Energy Efficiency and Building Science News

Monarch at Waugh Chapel Multi-family Development Uses Typar for Weather Protection System

Tue, 2019-07-23 15:06
Sponsored Headlines

When construction began on the new 246-unit Monarch at Waugh Chapel multi-family development in Gambrills, Maryland, protecting the building from the elements was a primary concern. That’s why subcontractor RPM Construction turned to TYPAR® for its weather protection needs. The construction team installed a total of 175,000-square-feet of MetroWrap™, 1,000 Flashing Panels, 600 rolls of 4-inch straight Butyl Flashing, 140 rolls of 9-inch Flexible Flashing, and 525 rolls of TYPAR® Construction Tape. 

See why the pros identified the TYPAR Weather Protection System as the superior choice for this project—along with key considerations for choosing a weather-resistant barrier.

The full article can be found on the Walls & Ceilings website.


D Magazine Features ANDRES' First National Bank Tower Project

Tue, 2019-07-23 14:55
Sponsored Headlines

After three years of starts and stalls, the 1.5 million-square-foot First National Bank Tower—which occupies the largest vacant block in the core of downtown Dallas—is getting a savior. Todd Interests is taking control, bringing with it new funding and a long track record of success. 

First National Bank Tower (Photo by Justin Schwartz)

Work on the 52-story tower at 1401 Elm Street quietly began ramping back up in recent days, while the deal with Todd Interests was still being ironed out. That’s because the project must hit a completion target of year-end 2020 to qualify for millions in entitlements.

Former redevelopment lead Drever Capital Management, which acquired the property in 2016, will continue in an advisory role, said Shawn Todd, CEO and founder of Todd Interests. “Maxwell Drever and his team gave it all they had and should be applauded for their efforts and for keeping the property out of foreclosure,” he said in a statement. “Our firm, this project, and our city will benefit greatly from Maxwell’s advisory role moving forward.”

The black-and-white skyscraper, bounded by Pacific Avenue and Akard, N. Field, and Elm streets, was the original Dallas home of First National Bank. Designed by noted architects George Dahl and Thomas E. Stanley, it was the tallest tower west of the Mississippi River when it opened in 1965, said Philip Todd, project lead and partner at Todd Interests: “First National Bank Tower will soon stand tall again, as it will undergo one of the largest historic renovation’s in the history of the United States.”

Todd Interests has had a string of impressive downtown redevelopments—the historic post office at 400 N. Ervay St.; the 30-story One Dallas Center on the DART rail line at St. Paul Street; and its latest venture, an 18-building mixed-use project called East Quarter. 

Philip Todd called First National Bank “the most complicated and challenging adaptive reuse” Todd Interests has ever taken on—not only in the complexity of the redevelopment itself, but in additional entanglements that involve legal documentation to qualify for Historic Tax Credits. What has saved the project as it has languished in recent years, he said, is the “unwavering commitment of Andres Construction and its loyal subcontractors” and Dallas’ ongoing willingness to provide TIF support.

Todd Interests has assembled an A-team of partners on First National Bank Tower: Berkshire Hathaway’s American Housing Partners will acquire the federal tax credits, statewide lender Stonehenge Financial will assume the statewide credits, and longtime equity partner Moriah Real Estate, which participated in the redevelopment of One Dallas Center, is at the top of the equity stack at $100 million. 

Construction resumes on the project at 1401 Elm St. in Dallas. About 500 workers are expected to be on site daily. (Photo by Justin Schwartz)


Merriman Anderson Architects has been involved in the project from the start; it was first engaged to work on a feasibility study when the tower went up for sale. “Since that time, we have been fortunate to continue with the project through owner and programmatic changes, said Aimee Sanborn, principal and team leader at Merriman. “We passionately believe that the current design and program is the highest and best use for the project and will greatly benefit downtown Dallas.”  

The massive redevelopment will focus on four uses: apartments, hotel, restaurants, and retail. A 200-room hotel, which will serve as a Texas flagship for Thompson Hotels, is scheduled to open on Sept. 1, 2020. The residential component will feature 318 luxury apartments, including some on the 48th floor—the highest in downtown Dallas. 

Kourtny Garrett, president and CEO of Downtown Dallas Inc., said the project “will transform downtown’s last major vacant building in the heart of a very active part of the center city, infusing life into a full city block that has been dark for a decade.

“Its magnitude is unparalleled,” she said. “At 1.5 million square feet, four projects in-one, the largest tax credit deal in the state’s history, local Tax Increment Financing, and significant private investment, it is one of the most complex redevelopments in the city to date.”


LP WeatherLogic Barrier System Protects Against Air & Water

Tue, 2019-07-23 14:43

Protect against air and water during construction and for years to come.

LP WeatherLogic® Panel

A water-resistive overlay is permanently bonded to the board and the edges are sealed. Applied as your framers install the sheathing, eliminating the need for a secondary wrap.

LP WeatherLogic® Seam & Flashing Tape

The LP WeatherLogic system comes with an AAMA 711-13 approved acrylic tape, specially formulated with one of the industry's most advanced adhesives. The tape is available in 3.75" and 6" widths and comes with squeegees in every box, used to smooth the tape to help ensure a firm seal.


Hemp Used for Construction Gains Popularity in U.S.

Tue, 2019-07-23 12:44
Building ScienceEnergy Efficiency

Builders who use natural materials in the United States have seen interest grow in "hempcrete," a renewable building material made with hemp that can take the place of traditional drywall, insulation and siding.

Since the 2018 Farm Bill legalized industrial hemp, the construction material -- used for 30 years in Europe -- has captured the imagination of American builders and homeowners.

The Highland Hemp House in Bellingham, Wash., is a solar-powered 1800s home with hempcrete-insulated walls. Photo courtesy of Hempitecture Inc.

"This year is the biggest year in hemp construction and it's really just beginning," said Tommy Gibbons of Ketchum, Idaho-based Hempitecture Inc.

Chipped hemp bark, lime binder and water are mixed together to make hempcrete. The material dries to a strong, stonelike substance that's fireproof, mold-proof and insect-proof.

Walls can be constructed by crews without power tools who mix the ingredients together in buckets and pour them into wooden forms.

In Bellingham, Wash., homeowner Pamela Bosch worked with Hempitecture to build a 2,000-square-foot hempcrete addition to her 1898 Highland Hemp House that overlooks the San Juan Islands.

"It's not a small experiment; it's a legacy-size demonstration," Bosch said.

She started her renovation looking for "natural insulation that didn't have toxic fiberglass or foam," she said. "I read about how hempcrete is used in Europe and never looked back."

A European dome home is constructed with hempcrete. Photo courtesy of Sergiy "Doctor Hemphouse" Kovalenskov

Helps the air

Hempcrete is a "carbon-negative" building material. The cellulose inside 2.5 acres of hemp can absorb more than 22 tons of atmospheric carbon dioxide, according to an Australian study. Hempcrete walls continue to sequester greenhouse gases as they cure.

The material is an antidote to the polluting construction industry, which belches out water and air pollution and fills landfills, said hempcrete pioneer Steve Allin, of Kerry, Ireland. Allin's 2005 book, Building with Hemp, and his workshops in the United States have been the catalyst for hundreds of builders to try their own hempcrete projects.

Hempcrete takes the place of fiberglass insulation and sheet rock and can be covered with a lime plaster for smooth walls. It is not load-bearing like sand-and-gravel concrete, but can be built around a supporting timber frame.

The 9- to 12-inch-thick walls create an insulation envelope, keeping the house cool in summer and warm in winter. Walls also "breathe" with vapor permeability that keeps air inside fresh and prevents mold rot, according to European natural builder standards.

Homeowners should consider hempcrete for remodeling and repairs, Allin said. "Not all that many people get to build their own house. It's not all about luxury homes."

Hempcrete does not require expensive building equipment and can be applied by teams of relatively unskilled workers, he said. "Hempcrete can be built with community participation on a very local level."

John Patterson, owner of Tiny Hemp Houses, stands beside a hempcrete retrofitted structure. Photo by Jean Lotus/UPI

Not easy to obtain

But it's not so easy to build a hempcrete house in the United States.

For one thing, hemp hurd, the plant material, is tough to acquire locally. Bosch and others have had to import hurd from Europe.

Farmers in this country have only just begun to grow hemp after it was formerly illegal in the United States for 80 years because of its relationship to its cousin, marijuana.

U.S. farmers appear more interested in growing the crop for CBD. That requires a short bushy plant, not the tall reed-like fiber variety. If farmers do grow the fiber plant, very few U.S. factories can process the crop.

"We need many processing facilities on the state level," said civil engineer and hempcrete builder Sergiy "Doctor Hemphouse" Kovalenkov of Hempire USA in Los Angeles.

The secret to sustainability is working with local farmers who can grow hemp close to the site, Kovalenkov said, adding, "There's no point in shipping hemp hurd from Poland when it could be grown locally."

Kelly Thornton of Boulder, Colo.-based Left Hand Hemp said, "There should be millions of acres grown and processing facilities around the country like silos for the farmers to bring in their crops."

The lack of hemp-processing facilities is the bottleneck unlocking the potential of hemp's many uses, he said.

Another challenge for builders is that hempcrete has not been incorporated into building codes, said John Patterson, a 30-year expert carpenter in Fort Collins, Colo., who constructs "tiny hemp houses."

Certifications sought

U.S. hemp builders plan to form a trade association this year whose goal would be creating a path to include hempcrete in residential building codes. The group also would submit the material to U.S. Green Building Council, which grants LEED certification for sustainable buildings, Patterson said.

Other natural-materials building processes, such as strawbale construction, have paved the way for hempcrete in the International Code Council's International Building Code.

Without proper certifications, it's tough to acquire home insurance, building permits and construction professionals who will sign off on hempcrete projects.

"We are working our butts off trying to get architects and engineers and building officials to understand that hempcrete can meet or exceed the intent of the code," Patterson said.

This year, some architects have taken notice of the material's potential.

In June, students used hempcrete to insulate a small building on the Princeton University campus at the School of Architecture's Embodied Computation Lab, Gibbons said.

"The material itself is exceptional, and it's incredibly exciting that our students got to see it and apply it with a hands-on experience," said Grey Wartinger, manager of digital fabrication, research and technologies at the lab.

A student works with hempcrete on a building project on the Princeton campus in June. Photo courtesy of Tommy Gibbons

Lower prices

Gibbons sees hempcrete as a way to build attainable homes for lower prices with hempcrete prefabricated walls, bricks, a spray application and even eventual 3D printing of hempcrete structures.

"We've seen the economics of this material, and how it can create jobs and build homes. We can help solve a lot of insecurity for people in my generation who can't afford their own shelter," Gibbons said.

Hempcrete is attracting homeowners who want a "rapidly renewable plant-based material that can change our manufacturing processes and move us away from oil," homeowner Bosch said.

For hempcrete pioneer Allin, the big picture for hemp is its role in fighting climate change.

"We need solutions. We've spent the last 20 years telling people about climate change, and with hempcrete, we have this path to reduce our carbon in the construction industry," he said.


L&W Supply Opens Three Branches

Tue, 2019-07-23 12:34

L&W Supply, a unit of ABC Supply, opened new locations in Modesto, Calif.Boise, Idaho, and Green Bay, Wis. Each location will offer wallboard, steel framing, acoustical ceilings, insulation, plastering, and other interior building products and materials.

Manny Inostros will serve as the branch manager for the Modesto, Calif., location. Inostros joined L&W Supply in 2011 and graduated from the distributor’s branch manager training program in 2019. Inostros began as a stocker/helper in the San Jose, Calif., branch and has served in roles with inside sales and as a branch supervisor. The Modesto branch represents the 8th northern California location for L&W Supply and the 16th overall across the state.

“The new Modesto branch fills a geographic gap in the footprint of the district that will allow us to better serve customers in the central valley,” said Don Wolf, district manager of Northern California/Nevada for L&W Supply.

Broc Whipple will serve as the branch manager of the Boise, Idaho, location. Whipple has held various positions, including stocker, inside sales, and branch supervisor, in his 20 years with the Chicago-based distributor. The Boise location is the 4th in Idaho for L&W Suppler.

The Green Bay, Wis., location represents a relocation of an older L&W Supply branch. Austin Heideman will be the branch manager of the new Green Bay location. Heideman previously served as the branch manager for the company’s Wausau, Wis., branch and has 15 years of industry experience, according to L&W Supply. The location is the 7th branch across Wisconsin.

With the three greenfield openings, L&W Supply, a specialty distributor of ceiling systems, steel framing, and other building materials, will operate over 170 branches in 35 states. The distributor opened locations in TexasVirginia, and California in June.


How Not to Kill Your Client

Tue, 2019-07-23 12:21
Building ScienceEnergy Efficiency

Most attached garages are unconditioned and effectively “outside,” so the wall between an attached garage and living space is part of a home’s thermal enclosure. The energy performance of the homes I build is important to me, but it turns out there are other important reasons for focusing my air-sealing efforts on the garage wall. For one, it’s an important fire barrier. According to the U.S. Fire Administration, around 7,000 residential fires start each year in the attached garages of one- and two-family homes, and the majority of these fires spread further and caused more damage than other residential fires, largely because of all the fuels—flammable liquids, paints, chemicals, ammunition, recyclables, and other items—stored in garages. This array of fuels also hints at the toxic cocktail of fumes from vehicles, lawn equipment, and all those chemicals that may be getting sucked into the house and creating terrible indoor air quality.

The most common and noxious of these gases is carbon monoxide (CO), which in the best of cases is released for only a moment when a car drives in or starts up. In the worst cases, however, the release of CO into the garage can be a sustained event that turns fatal. A report last year in The New York Times, “Deadly Convenience: Keyless Cars and Their Carbon Monoxide Toll,” examined cases of car owners leaving their cars running because the drivers didn’t know the cars were still running after they were parked. The CO buildup in garages leaked into the homes, tragically resulting in the deaths of occupants. For builders, all these issues—energy performance, fire safety, and indoor air quality—serve as so many wake-up calls, signaling what’s at stake if we don’t air-seal the garage wall.

In a typical one-story garage attached to a two-story home, the roof ties into the second-floor walls; in this case, into the knee walls of a much larger attic area. Below the rim joist, the author’s crew hangs drywall on the garage side of the wall, ahead of the drywall crew that will install drywall in the rest of the house.

This allows him to begin air-sealing penetrations, such as packing electrical boxes with a two-part, closed-cell spray foam.

The rim-joist area and the wall above the rim joist are insulated to the roofline of the attached garage with 6 inches of closed-cell foam. This not only insulates the wall but also seals all penetrations.

Complete Separation

In the photos in this article, we show a typical one-story garage attached to a two-story house. To create a tight, thermal barrier, my crew starts by hanging drywall on this wall after framing. This happens before the drywall subs come and hang all the drywall in the rest of the house. Most of the time, our exterior wall framing is 2x6. (Yes, the garage wall is an exterior wall; it’s the thermal boundary between inside and outside the home.)

Installing this drywall ahead of time allows us to take care of two critical details: penetrations and the roof bypass.

The garage-wall cavities are insulated with an open-cell spray foam. If installed to a depth of at least 4 inches, an open-cell foam provides a decent air seal to close off small cracks and gaps in the stud bays. Notice that the author frames with a California corner, so wall corners can be filled with insulation.

Penetrations. We install a two-part, closed-cell spray foam around any electrical boxes or other wall penetrations to create a tight air seal. In most residential garages, it is not practical to avoid outlets or lights on the garage wall; they serve a practical purpose for homeowners, and eliminating them is really not an option. But because we need to have these penetrations, we need to be certain they don’t leak.

Roof bypass. This detail is perhaps more important because it represents such a big air bypass. We seal the garage wall all the way up to the roofline. This means we extend the drywall to the rim joist, and, above the ceiling line in the garage, we sheathe to the roofline with 1/2-inch plywood or another sheet good. (This is one good place for Thermoply, which I would not ordinarily use as an exterior sheathing, but in this case is used solely as a backer for the insulation; the smooth surface adheres well to tape at the seams for a good air seal.) Without this added sheathing, the wall above the ceiling is completely connected to the second story of the home. It’s best to do this at the framing stage, before the mechanicals are installed. But we’ve also followed on the mechanical installations by sealing any wiring and other penetrations that run inside the garage wall.

On the house shown in these photos, we insulated the walls with Rockwool and with open-cell foam. While we need closed-cell foam to air-seal large and direct penetrations, we get a pretty good seal with open-cell foam in the wall cavities, as long as we apply it at least 4 inches thick. On the wall above the rim joist to the garage roofline, the insulation contractor will spray the sheathing with 6 inches of closed-cell foam so we get a good air seal and thermal barrier.

Thermoply is not a sheathing the author ordinarily uses for structural framing.

However, it proves to be an excellent backer for airsealing above the rim joist to the roofline. The reverse side of this sheathing was later insulated with 6 inches of closedcell foam.

Sill Seal

With a new home, we like to have the garage slab poured integrally with the rest of a structural slab for the house. But in existing homes we are renovating, it’s not uncommon to have the garage slab butting the main house foundation, whether that foundation is a structural slab, a stem-wall foundation, or a full basement. And whether there is a step up to the house from the garage slab or not, in all cases, we have a critical air seal to make between the concrete and the bottom sill of the garage wall.

For sealing the slab-to-wall transition, the easiest method is to simply lay a fat bead of caulk in the gap created by the foam sill seal between the foundation and the framing. A top choice is a single-component, nonhardening synthetic rubber, such as Tremco’s Acoustical Curtainwall Sealant (what has been commonly dubbed “black death” in the field). This material stays flexible for an incredibly long time. But an exterior silicone formulation for concrete or a high-quality polyurethane sealant can also work for this application. In any case, I prefer sealants that come in sausage packs and that can be applied with a professional-grade gun. A sausage gun is so much easier to control and much less tiring to use than a skeleton gun.

Seal along the base of the wall between the concrete and the bottom plate with more than the standard foam sill seal.

A siliconized acrylic caulk formulated for concrete or a good-quality polyurethane sealant works as a sealant here.

If there’s a step up from the garage and the concrete-to-wood connection is on the vertical plane of the wall, I prefer to use a fluid-applied sealant, such as Prosoco’s R-Guard Joint & Seam Filler. Or I use Blue Barrier, which is a bit thicker than R-Guard and fills gaps up to 3/4 inch. I do this before installing the drywall, and then we run the drywall past the sill plate to cover the joint and create a gasket effect. (We use the same material on the exterior walls for sealing the concrete-to-wood connection at the sill, usually after the walls have been sheathed. In this case, we will often run a temporary line of tape on the concrete so we get a clean line with the sealant that we can cover with the siding.)

The Prosoco product line evolved from material developed in Japan for installing windshields; the material is both adhesive and waterproof, and it sticks on just about any surface. These materials are moisture-curing compounds, so they bond directly to damp or dry surfaces, even green concrete, with no primer needed, and cure under a variety of weather conditions. Low temperatures and dry conditions will slow down the drying time, while high temperatures and high humidity or wet conditions will accelerate curing. But the bond will only improve over time, which strongly appeals to me. I also like that this material bonds without primer. In most other cases, there are almost always issues with sealing to concrete. Form oils, wax, concrete additives, and especially moisture all can affect the bond, and I always feel reserved about the long-term viability of an adhesive bond. These fluid-applied options form a “rubber barrier” at the base of the wall and do an excellent job at stopping airflow.

Bonus Coverage

The issues surrounding air-sealing are much more involved if the house has a “bonus room” over the garage. In my market, we don’t do those much, but they are popular in the production market, and they are often done very poorly. For information on this, see the article “Fixing the Bonus Room” by Matt Bowers (Mar/17), a home-performance contractor in upstate New York who has made a steady business of solving the comfort problems associated with living space over the garage. It’s worth keeping in mind that while the air leakage into these above-garage rooms during a cold, New York winter can render these rooms nearly uninhabitable, the problems don’t stop there. They are also potential indoor air-quality nightmares. 


Energy Upgrade Performed as Warranty Service Fixes "Bonus Room" Over Garage

Tue, 2019-07-23 11:36
Building ScienceEnergy Efficiency

I’m a HERS rater and project manager for Airtight Services, a home-performance contractor in upstate New York. In the photo at right, one of our carpenters is cutting open the gable-end wall over a garage on a brand-new house. He’s starting one of the jobs that have become part of our bread and butter: an energy upgrade performed as warranty service for a home builder on a cold, leaky “bonus room” over the garage.

In our area, bonus rooms have been a common feature of new construction since the 1970s. That’s because builders here have optimized their plans to fit more houses on a development, and one way they create inexpensive square footage is to build a second-story room over an attached garage, framing the roof and the bonus room in one quick step using an attic truss. The bottom chords of the trusses form the garage ceiling as well as the bonus-room floor. Vertical webs of the trusses form the sidewalls of the room.

It’s a frugal way to build what could be usable space, but the result is often uncomfortable space. Time after time, we are called because a homeowner has just moved into a house, and the room over the garage is 20°F colder than the rest of the house in the winter—the main house is a cozy 68°F, but the bonus room is in the 40s or 50s. We find this condition not only in older homes built under obsolete codes, but in brand-new houses built to comply with the 2009 International Energy Conservation Code (IECC) and even in homes built under the recently adopted 2015 IECC. The example shown in this story—a typical case—is warranty work on a new house built to comply with the 2009 energy code.

Now that the 2015 IECC has been adopted in New York, rooms like this one are likely to cause new homes to flunk the building envelope airtightness standard. New York’s new energy code requires homes to achieve no more than 3 air changes per hour at 50 pascals of pressure (3 ACH50) during blower-door testing.

To construct a typical bonus room, the builder first installs OSB subflooring on the truss chord.

The vertical sidewall truss webs are insulated with kraft-faced fiberglass batts.

Next, the builder applies drywall to the room walls—leaving space below the drywall for the carpet installers to attach a tack strip.

After carpet and trim are in place, a huge air gap remains at the base of the wall, communicating with the cold vented attic.

The photos above show a typical bonus room at various stages of construction. Because the framing is basically a set of trusses, there is no wall plate at the bottom of the wall. As a result, there’s a gap—typically a big gap—at the bottom of the wall. This allows air to leak freely into the room from the space behind the wall, which is connected to the outdoors via the roof eave soffit vents.

Bonus rooms have big leaks. In pressure diagnostics, if I close the door to a bonus room and isolate it, I often measure a 20- to 25-pascal difference between the bonus room and the main house—and you can feel the air pouring in under the door.

To make matters worse, the typical forced-air heat for a room like this tends to underperform. The ducts serving the room typically are insulated to only R-4.2 (code now requires R-8 for ducts 3-in. or greater in diameter that run through unconditioned space) and run the 24-foot length of the garage through unheated space and then back to the furnace in the basement—often the longest duct run in the house. The thermostat is generally located in the family room on the first floor. So, controlled by calls for heat from the warm inside of the house, the furnace would struggle to heat the bonus room adequately even if the bonus room weren’t leaky, poorly insulated, and exposed on five sides to outdoor temperatures.

Bonus-room conditions can get extreme. We’ve walked into older bonus rooms, built in the 1970s or 1980s, with built-in dresser cabinets added to the knee wall, projecting into the cold space. One occupant’s main complaint was frosty underwear on winter mornings. Homeowners in these situations aren’t focused on their heating and cooling bills. They don’t care what it costs, or how much they will save; they just want to be comfortable.

Working from outside, a carpenter cuts into unheated space above the garage next to the bonus room


Before we start a job like this, I look in the bonus room to make sure that there aren’t valuable things hanging on the walls. We are going to be nailing up an air barrier from the other side and don’t want to knock anything off the wall. I also find out where the duct registers are, so that we’ll have an idea of what to expect when we open up the space behind the wall. And finally, I like to double-check the room dimensions to make sure that when we cut open the gable end of the house, we won’t cut into the occupied space. I take a measurement from the window to the knee wall inside the room, and then we measure off the same window when we choose a place to cut open the gable end.

Gaining entry through the gable end is the simplest approach. We could cut through the drywall from inside the room, or we could go in through the ceiling of the garage, but then it would be hard to patch up the holes we would make. Vinyl siding just unzips; then you take a couple of nails out and peel back the housewrap, cut out a piece of sheathing, and climb in. On the way out (see photos, page 64), you replace the sheathing, tape up the housewrap, rehang the vinyl, and move along.

Under the low roof, he finds the back of the bonus-room wall, with a plastic air barrier stapled to the wall over the fiberglass insulation (but not sealed at the top or the bottom)

With the plastic removed, the R-19 batts bulge out beyond the 2x4 framing.

Where the wall meets the floor, nothing blocks air from flowing through fiberglass batts installed under the subfloor

What we found in the space behind the bonus-room knee wall in this house is typical. The white plastic air barrier is not sealed at the bottom or the top. (Air barriers on knee walls are required by code. This requirement is found in Table R402.4.1.1 of the 2015 IECC. The same table requires the knee walls to be sealed at top and bottom.) With the plastic sheeting removed, the R-19 fiberglass insulation bulges out from the 2x4 wall framing cavities. When I fold back that kraft-faced wall insulation at the bottom, we see the condition under the floor: two insulation batts stuffed up into the truss bays from below, with the lowermost batt’s kraft facing stapled to the truss sides to hold the insulation in place. And it’s a little hard to see in these photos, but the joint between the subfloor and the drywall is open half an inch—and there’s daylight between the baseboard and the carpet.

Click to enlarge.

Tim Healey

As originally built (above left), the bonus room’s air barrier allowed free airflow through the fiberglass insulation under the floor and in the walls. The author’s repair (above right) created a rigid air barrier that air-sealed the living space, protected the floor and wall insulation from air infiltration, and boosted the wall system’s nominal insulation value from R-19 to R-24.


Carpenters notch and fit 2-inch XPS insulation board over the wall studs, fastening the board with nails and washers as they compress the R-19 batts into the wall framing cavities.

On the left side of the illustration above, you can see the deficiencies that made this room so uncomfortable; on the right are the repairs that our crew made. When the original plastic air barrier membrane was installed, somebody took time to notch it out around the bottom chords of the trusses—but it was never sealed. Our goal was to seal our air barrier all the way around the truss chords and seal it to the drywall underneath.

Fabric wraps are difficult to work with, so we like to use a beefy rigid air barrier material here. For this job, we used 2-inch XPS foam, which adds R-value and is stiff enough to compress the existing R-19 batts into the 2x4 wall cavities (note: some jurisdictions may require a fire-rated material such as Dow Thermax at this location).

They cover the whole wall with 2-inch (R-10) XPS, notching around the upper truss chords at the top of the wall.

We notched the XPS out carefully to fit around the trusses, making sure the board contacted the drywall at the bottom of the truss cavity, and attached the boards with 3-inch nails and washers, which we have found give a better positive attachment than ordinary cap nails.

Compressing the R-19 batts into the 2x4 cavity gives an effective R-value of R-14; in new construction, a high-density R-15 batt would cost less and perform better. But with the XPS, our retrofit still achieves a nominal R-24. And by abating the convection and thermal bridging that had reduced the effectiveness of the original R-19 batts, our upgrade substantially boosts the wall’s performance.

At the top of the wall, the existing air barrier membrane was never sealed to the vent channel installed under the roof sheathing—again, exposing the fiberglass to wind-washing. So when we notch the foam board around the top chords of the trusses, we seal the edges to the vent channel as well as to the trusses.

They seal the foam board to the framing with gun foam, sealing duct penetrations at the same time.

Finally, they tape the seams between sheets of foam board to perfect the airtight seal.

Finally, we seal the seams between the pieces of foam board using 3M Venture Tape Metal Building Facing Tape, which clings tenaciously and is much cheaper than some specialty tapes.


As I mentioned earlier, the ductwork for a bonus room tends to be the longest duct run in the home, and it’s usually only insulated to R-4.2. The airflow in the ducts suffers from friction losses, and the air loses heat to the cold attic space as it makes its way to the room. So after we seal up the insulated air barrier for the bonus-room knee wall, we install a thick blanket of cellulose insulation around the duct. This helps keep the supply air coming into the room nice and warm. We put about 10 inches of insulation on all sides of the duct—including below it—for a good R-30 to R-40.

With the new foam-board air barrier in place and sealed with gun foam and tape, the crew augments the insulation wrap on the flexible heating duct with an additional 10-inch blanket of blown cellulose.

With that done, all we have to do is go back out through the hole in the wall, nail the OSB sheathing back in place, staple the housewrap back onto the wall, and tape the housewrap seams. Then we reattach the vinyl siding, and we’re done. It’s a one-day job; start to finish, the whole job typically takes about three hours for each side of the room.

Then the carpenters nail the cut-out section of wall sheathing back in place, and reattach the housewrap and seal the seams with tape.

Finally, they replace the vinyl siding, leaving no visible trace that any repair ever happened.

So how could a builder avoid this callback? Well, the big problem is the air barrier, and the major flaw is the floor-to-wall joint. So when the subfloor and the drywall are both installed, but before trim or carpet are installed, one good step would be to air-seal that joint with a can of gun foam—or better yet, with tape. Blocking nailed between the trusses behind the drywall at the wall base, to make up for the missing wall plate, would also help.

If you are hoping to meet an above-code standard or to surpass code-required insulation and airtightness levels in this relatively vulnerable room, there’s another option: Specify a truss with a shorter knee wall, and frame a whole separate wall inboard of that for your room. That way, you’ll have room for more insulation than an R-19 batt.


Court Says ICC Can Proceed with Copyright Complaint Against IAPMO

Tue, 2019-07-23 11:06
Building Codes

A federal court on Sept. 19, 2016 cleared the path for ICC Evaluation Services to proceed with its copyright infringement complaint against the International Association of Plumbing and Mechanical Officials, Inc. when the court denied IAPMO’s motion to have the case dismissed.

On Jan. 13, ICC-ES, a subsidiary of the International Code Council, filed a lawsuit against IAPMO and IAPMO Evaluation Service, LLC, in the U.S. District Court for the District of Columbia, alleging the willful and unauthorized copying of at least 17 ICC-ES copyrighted works, including 14 ICC-ES evaluation reports and four acceptance criteria that thousands of designers, manufacturers, and building safety and fire prevention professionals rely on to ensure the highest standards of construction safety across the United States.

IAPMO responded by asking the Court to dismiss the case.

U.S. District Judge Emmet G. Sullivan struck down IAPMO’s arguments to dismiss ICC-ES’ federal copyright claims as “unavailing,” noting that side-by-side comparisons of ICC-ES’ copyrighted materials with IAPMO’s allegedly infringing works that were presented to the court as evidence along with ICC-ES’ complaint, “could permit a reasonable observer to conclude that appropriation occurred.”

IAPMO now must submit an answer to the court responding to ICC-ES’ copyright infringement claim by Oct. 3.


Can a Private Organization Copyright the Law?

Tue, 2019-07-23 10:59
Building Codes

Potential productivity benefits for architecture, engineering, and construction may depend on the outcome of copyright litigation by the International Code Council (ICC) against San Francisco-based startup UpCodes. The firm, which aims to reduce perceived bottlenecks in the implementation of the nation’s 93,000 building codes, faces charges that its public posting of codes undermines the public-private partnership that develops them.

The United States Supreme Court Building in Washington, D.C. While the ICC's case hasn't reached this court, other intellectual property cases certainly have. (Claire Anderson/Unsplash)

The nonprofit ICC, which prepares the International Building Code and other model codes adopted by multiple jurisdictions, contends that UpCodes has appropriated its property and “does not need to violate ICC’s copyrights to further its claim to innovate,” an anonymous ICC spokesperson commented for this article through its public relations firm. UpCodes regards its practice as fair use, citing precedents establishing that information “incorporated by reference” into law (the applicable legal term) enters the public domain. Other appeals courts, ICC counters, have protected copyrights in cases it considers comparable.

The suit involves a tension that jurists have long recognized in copyright law: the need for material support and incentive for creators (who have exclusive rights “for limited times” under the Constitution’s copyright clause) versus the need to prevent monopoly control from stifling the circulation of ideas. The conflict pits ICC’s interests in codebook development and sales, and its assertion that its website already provides adequate access, against UpCodes’ interests in expanding access and linking codes with building information modeling (BIM) systems.

An example of the UpCodes plugin in Revit. (Courtesy UpCodes)

Brothers Scott and Garrett Reynolds, the first formerly an architect with KPF and the latter an engineer with construction-software firm PlanGrid, founded UpCodes in 2016 to streamline the often-tedious aspects of code review. Automating this process, they contend, can reduce errors and free up architects’ attention and time. Opposing ICC’s don’t-fix-what-ain’t-broke legal position, Scott Reynolds commented, “I think it actually is a broken system.” An estimated multi-billion-dollar annual expenditure goes into construction rework due to compliance errors, so there’s a huge amount of wasted expenditure simply from code mistakes.”

He is not alone in finding code review laborious. The Economist, citing McKinsey Global Institute findings on the $10 trillion construction industry’s historically low productivity, advocates standardizing codes, alongside steadier public infrastructure investment and incentives for BIM adoption, as strategies to modernize the sector. The National Association of Home Builders estimates that 24.3 percent of the final price of an average new single-family house, over $84,000, is attributable to regulation, with an even higher burden, 32.1 percent, for multifamily developments.

UpCodes, supported by the prominent seed accelerator Y Combinator, offers two products out of beta as of May 2019: UpCodes Web, a searchable code repository, and the extension UpCodes AI, a Revit add-in that analyzes 3D digital models and provides real-time compliance checks. The web product is the target of ICC’s suit. The AI product uses the code database as its foundation, automatically synchronizing with code updates; it is often compared to editorial tools like spellcheckers and Grammarly, or the Lint analytic utility for Unix. A key feature of UpCodes AI, Garrett Reynolds notes, is that “checking models in 3D is orders of magnitude easier than checking 2D plans… For example, stair headroom clearance is pretty difficult to tell in a 2D plan, but in a 3D, we can just draw a box and check for intersections.”

The ICC views UpCodes as infringing on a successful process that makes U.S. buildings safe, balancing efficient standardization with adaptability to local conditions. Its statement notes that the organization “develops the model codes through a rigorous, transparent, consensus-driven process involving nearly 55,000 industry sector members and over 9,500 government agency members. It provides free access to view the codes on its website. The sale and licensing of the codes to professionals and governmental organizations defrays the cost of the code production process.”

“The Code Council’s position is that incorporation into law does not terminate the copyright in the Code Council’s model codes,” the statement continues, adding that “UpCodes—a for-profit company—is trying to solve a problem that does not exist because the Code Council already makes its model codes freely available to all to read on its website.”

The ICC’s website and some jurisdictions, Scott Reynolds allows, offer online access to codes, but not in practical form. “You can’t copy. You can’t paste. You can’t print,” he says. “You just can’t work with the text. You can simply have read-only access, and from a professional standpoint, or [for] a homeowner, that just doesn’t suit the needs that you have. And then there’s even jurisdictions like Michigan where you can’t access the code; they don’t host free access.” Such limitations, he argues, amount to constriction of the very processes ICC claims to promote. They arguably border on privatizing the law: “If you are legally bound to follow rules of the government, and you will face civil and criminal penalties if you don’t, you have to be able to read those rules. They can’t be put behind a paywall.”

“The key distinction in these cases is not whether something is a code or not but whether it’s legally binding,” noted Mitch Stoltz, an intellectual-property attorney with the Electronic Frontier Foundation (EFF), supporting the Reynoldses’ position with a historical comparison. “Supposedly the Roman emperor Caligula would write the laws in small print and hang them up very high, so no one could actually read them. That’s a problem for democracy.” The EFF is not involved in the ICC–UpCodes suit but is defending the nonprofit organization Public Resource in a similar case involving publication of documents from three standards-development organizations: the American Society for Testing and Materials, National Fire Protection Association, and American Society of Heating, Refrigerating and Air-Conditioning Engineers.

ICC’s charge that loss of copyright could impair code development, Stoltz adds, does not square with the underlying economics. “They are happy to make money by rationing access to codes,” he said, but “their business model in the end doesn’t depend on that, because the actual work of creating these codes [in] most industries is done by volunteers from that industry and from the government. They’re not paying people to write the things. People are coming together voluntarily to write them.”

The Reynoldses emphasize that UpCodes is not meant to put code specialists out of business, but to help more people implement codes properly and safely. “We really wanted to democratize the process of code research and empower all individuals or professionals to navigate through that process themselves,” Scott said. “The first thing we tell a user is, UpCodes AI is not a replacement for a professional code consultant,” Garrett added, noting that “spellcheck doesn’t put editors out of work.” He described the ICC’s work as “really important, and we want them to continue doing it. Their main revenue stream actually isn’t from selling books of the law. It actually comes from program services: things like consulting, accreditation, training, consulting.”

UpCodes AI flagging violations on a Revit model. (Courtesy UpCode)

An initial co-plaintiff, the American Society of Civil Engineers (ASCE), withdrew from the suit but maintains that its materials are copyrighted and describes its economic model differently. Alexa Lopez, ASCE’s senior manager for public affairs and media relations, provided a written comment: “Upcodes is a for-profit entity that posted these copyrighted materials online for profit. For awareness, ASCE is a 501(c)(3) non-profit organization with a long history of promoting the education, science and profession of civil engineering. ASCE expends significant resources on standards development, including convening staff and volunteer experts from across the country and globe, compliance with ANSI standards, public input, and balloting. ASCE recoups some of these costs through standards sales, the proceeds of which are used to promote the Society’s educational and charitable 501(c)(3) activities. The Society’s standards are protected by copyright and registered with the U.S. copyright office.”

The most relevant precedent, the Reynoldses and their allies hold, is Veeck v. Southern Building Code Congress International, Inc., 293 F.3d 791 (5th Cir. 2002), where the Fifth Circuit Court of Appeals held that model codes developed by the SBCCI (one of three organizations that merged to form the ICC in 1994), once enacted into law, forfeited copyright protection. An earlier case, Building Officials & Code Adm. [BOCA] v. Code Technology, Inc., 628 F.2d 730, 734 (1stCir. 1980), also defined Massachusetts building codes as law not protectable by copyright.

The ICC’s position distinguishes between legislatively-generated laws and model codes developed through public-private partnerships, pointing to decisions in which copyrights incorporated by reference were preserved for other privately created information, such as the American Medical Association’s procedure-coding system, or a used-car valuation guide mentioned in insurance regulations. Stoltz contrasts Veeck, where code was explicitly made part of the law, with the used-car price book case (CCC Information Services, Inc. v. Maclean Hunter Market Reports, Inc., 44 F.3d 61 (1994)): “The court said that didn’t put that book in the public domain. But that’s different from saying ‘This document establishes rules for fire safety in the construction of an office building, and it is hereby incorporated into this regulation’”

To Garrett Reynolds, ICC’s action is “a suit where they said, ‘Let’s try to kill them out of the gate.’ I think they thought they could bury us in litigation costs, and they have succeeded in that strategy many times” with other firms. Scott noted that of the three groups that formed ICC, “one of those three is SBCCI, and then another one of those three is BOCA. So, two of those three organizations have already litigated the case and lost. But now it’s a new entity, and they can threaten, and they can litigate again. So yeah, I do think it’s a tactic of intimidation.”

An example of the UpCodes plugin in Revit flagging several violations. (Courtesy UpCodes)

Architects contacted for comment describe UpCodes as a time-saver, though not a panacea.

Rob Pivovarnick, AIA, a senior project architect at Michael Graves Architecture & Design and an early adopter of UpCodes AI, has found the program useful, though not without a few false-positives—e.g., mistaking 20-inch stadium stairs, meant for seating rather than walking, for ordinary steps limited by code to a seven-inch height. It is particularly helpful, he said, in checking ADA-compliant bathroom details.

“It looks for the ambulatory stall, it checks returning spaces, it checks for accessible sinks and toilet-seat heights.” He is careful to manage expectations: “There’s no software out there that you’re going to unleash and say, ‘This thing is doing my code review,’ and they make that clear on their website…. I don’t think UpCodes or Revit are ever going to preclude the use of a code consultant on a job. There’s just too much information there for somebody to build a pro piece of software that’s going to run all those checks.” Yet, since UpCodes is currently free of charge, “if it catches one thing, then it’s valuable,” he added. “[It] can be a $100,000 problem if the toilet room isn’t big enough to hold the ambulatory stall, and then it gets built, and then walls need to move and plumbing needs to change.”

Depending on what price point UpCodes eventually chooses for individual or network licenses for its AI product, Pivovarnick speculated, it may be a valuable investment. At a previous firm he used MADCAD, a program that centralizes codes from ICC and other organizations, largely on a paid basis; he finds UpCodes more flexible, especially in the field. “Instead of having to remember the code section, I can type stairs or firewall or fire partition and things like that, and it brings up all the relevant sections, which is great.”

The ICC’s statement includes a description of its efforts in the digital realm: “We have worked with our members and partners to harness a variety of innovative ideas to take advantage of breakthroughs in technology, such as, and will continue to do so. Paramount, however, is ensuring that the public continues to have confidence that buildings are being constructed according to the most modern codes and safety standards.” If Pivovarnick’s experience is representative, free digital instruments are already performing more nimbly than their paid equivalents. It now falls to the courts to determine whether a copyright in this disruptive realm hinders or advances aims that all parties share.


JM Wool Production Line to be Built in McPherson, KS

Tue, 2019-07-23 10:52
Building ScienceEnergy Efficiency

Johns Manville (JM), a global building and specialty products manufacturer and a Berkshire Hathaway Company, announced a new Climate Pro®blowing wool production line will be built in McPherson, Kan.

“Climate Pro insulation is a preferred solution for many contractors and distributors,” said Mary Rhinehart, President and CEO of Johns Manville. “The production expansion at our plant in McPherson will help us meet current and future market demand for blowing wool.”

JM will begin construction on the expansion project later this year, pending various governmental approvals, and anticipates the completion in early 2021. When complete, JM will employ more than 330 people in McPherson.

“Our central location in McPherson gives us easy access to many markets and positions Johns Manville to offer more of this premium product to our customers,” said Bob Wamboldt, President of JM’s Insulation Systems business.

Climate Pro® blow-in fiberglass insulation fills those hard-to-reach cavities and corners while offering more consistent coverage – resulting in a more comfortable, energy-efficient home. It offers a range of R-values and is quick for professionals to install.

“Johns Manville is proud to be part of this community and we are eager to add people to our team,” said Mindy Lanning, Plant Manager in McPherson. “We will be hiring operators, maintenance technicians and warehouse employees. As part of our team, employees enjoy the stability of an established company and a strong family-like environment. We offer competitive hourly rates and training opportunities to learn new roles and develop new skills.”

Local and state officials applauded JM’s decision to expand in McPherson:

“Advanced manufacturing is a staple of McPherson,” Kansas Secretary of Commerce David Toland said. “The community houses a significant number of innovative, progressive manufacturing companies pushing the envelope in their industry. It is clear that Johns Manville has chosen the right location for its expansion.”

“This project is an important step forward in the McPherson manufacturing market. Johns Manville is an important corporate citizen in our community,” said McPherson Mayor Tom Brown.

“What an exciting win for McPherson, Kansas! We are grateful to our partners at the Kansas Department of Commerce for coming along side us to get this deal done. We are honored to have JM continue to invest and grow in our community,” said Kasi Morales, Executive Director of the McPherson Industrial Development Company.


Peter Pfeiffer POV – Spray Foam Detail & Considerations

Tue, 2019-07-23 10:43
Building ScienceEnergy Efficiency

There is more than one way to build an energy efficient wall assembly using spray foam as a key component. Being a new product on the construction scene, driven largely by changes in the energy code, where continuous insulation and air tightness are valued, it is clear that spray foam will become a much more common application. There are a variety of ways to install and integrate spray foam into a building assembly. To shed some insight please review the approach taken by energy-efficient building architect Peter Pfeiffer from Texas.

Peter Pfeiffer

No other insulation system I am familiar with provides the real r-value that spray foam does, accomplishes the air-sealing it does, or thwarts vapor flow as well. Closed-cell spray foam greatly reduces the chance for condensation within the framing of a home. I think it is critical that houses be built to thwart vapor flow correctly. I insulate all homes pretty much the same. However, in colder climates, I use 2x6 exterior walls, create a cold roof, and insulate the basement or crawlspace. 

Read Full Article


Bruce Harley POV – Spray Foam Detail & Considerations

Tue, 2019-07-23 10:06
Building ScienceEnergy Efficiency

There is more than one way to build an energy efficient wall assembly using spray foam as a key component. Being a new product on the construction scene, driven largely by changes in the energy code, where continuous insulation and air tightness are valued, it is clear that spray foam will become a much more common application. There are a variety of ways to install and integrate spray foam into a building assembly. To shed some insight please review the approach taken by energy-efficient building expert Bruce Harley from Vermont.

Bruce Harley

Spray foam can be a great material, but understanding its use is often hindered by overeager installers who emphasize the magic rather than the real properties of the products. Too often, I hear from clients that “my dealer said that I only need 2 in. to 4 in. of foam in my walls because it performs just like r-40 fiberglass and prevents any possible moisture problems.” It’s just not true. An r-12 wall is an r-12 wall, no matter what the material is. Cutting air leakage saves energy, but it doesn’t make up for a low r-value. For best performance, I use spray foam in a variety of ways when designing the shell of a home.

Read Full Article


Project Spotlight: A Green Professional Walks The Walk

Tue, 2019-07-23 09:32
Building ScienceEngineering & Testing

Chris Byers has a long history in the green building industry and currently works as a Commercial Solar Developer at Namasté Solar. Throughout his career he has assisted in the development and construction of over 24 MW of projects since 2016. Byers has designed and managed solar projects in the United States, Haiti, and Kenya. Because of this, it only seemed suitable that Byers himself take the same approach to sustainability that he has always advocated for when creating his own home. Recently, we had the opportunity to speak with Chris in order to learn more about the team’s approach to the building envelope.

The team Chris assembled included the Philadelphia based firm, Bright Common Architecture & Design, which is no stranger to working with 475 products. Chris’s home was designed by Jeremy Avellino of Bright Common and Jessica Jolin of Mobile Studio Design . The design was brought to life by the general contractor, Eric Favreau and his company Spindrift Carpentry, and Jon Riley with Casco Bay Insulation, who completed the interior air barrier and insulation.

Assembly Approach:

The project team decided to go with designing a double-stud wall with a CDX sheathing at the exterior. In order to combat the risk of condensation on the inside face of the CDX, they went with the go-to, INTELLO PLUS as the smart vapor control layer and primary air barrier, placed inboard of the insulation. Inboard of the INTELLO PLUS is a framed service cavity for electrical wiring and plumbing, reducing penetrations in the control layers and protecting the inboard air and vapor control.

Because you can never have too many air barriers (as long as they let the vapor dry out!), they chose to tape the sheathing seams with TESCON VANA, in addition to installing SOLITEX MENTO 1000 as the airtight and vapor open WRB. Chris said that the SOLITEX MENTO 1000 was especially durable, and he knows it will stay durable over time. As for the tape, according to Chris,“The TESCON VANA tape was super easy to work with, and stuck really well to the CDX.”

After selecting all the materials, the team decided to further optimize the assembly performance by creating a ¾” rain screen on the exterior using strips of locally sourced pine. They were pleased to know that the wall assembly can dry to the exterior, as well as the interior. Since the team used dense pack cellulose, which is hygroscopic, Chris knows moisture won’t build up. Furthermore, by creating drying capabilities in both directions, Chris states that they were able to reduce the risks of highly insulated enclosures. They wanted a wall design that would be, “dynamic, and handle the multiple temperature shifts and climate changes we incur in Maine.”

At windows they utilized EXTOSEAL ENCORS self-healing, form-fitting, tape at the sills, with vapor open CONTEGA SOLIDO EXO tape at the exterior jambs, and TESCON PROFIL split backed tape at inside corner connections at window interior.

Chris also explained to 475 that the INTELLO PLUS air barrier was connected to the sub slab vapor barrier providing uninterrupted vapor control. Above, the ceiling trusses act as uninsulated service cavities with taped sheathing above and insulation above that in the gabled attic. Finally, Chris noted that an energy recovery ventilation system was installed: “another key part to making the house healthy and balanced.” The final result is an elegant low-energy home that should perform for the life-time of the occupants and of the building itself.


In Puerto Rico, the Campaign For A Hurricane Proof House

Wed, 2019-07-17 19:19
Building Science

In Puerto Rico, nearly two years after hurricane Maria, the need for safe, affordable housing is still a massive challenge. "We have more than a half million people affected. And we have to build, minimum, 75,000 homes, " says Astrid Diaz, a well-known architect in Puerto Rico. She was part of a FEMA team that assessed the island's infrastructure after the storm.

Diaz often appears on television wearing her trademark yellow hardhat, promoting her "Casa Segura-Safe Homes" campaign.

Astrid Diaz is a well-known architect in Puerto Rico and has designed a new modular home resistant to hurricane-force winds. Greg Allen/NPR

But long before the storm, she urged residents on the island to develop a disaster plan and to make their homes hurricane-resistant. Since the storm, Diaz has a new project. She's designed a modular home, resistant to hurricane-force winds that she says can be built for $30,000. Not coincidentally, that's the maximum amount of assistance FEMA makes available for homeowners. "I started thinking that I need to design a house for people in Puerto Rico, a house where they feel safe."

Diaz's new modular home is on display at a building products factory in Toa Baja, about 20 miles west of San Juan, the island's capital. Right now it's just a prototype, a few walls and a roof of polyurethane foam — a lightweight, economical and durable building material.

"It's strong," because the foam panels are covered with a galvanized steel mesh that provide structure and load-bearing capacity, she says. Once the polyurethane foam and steel panels are available on site, Diaz says, "it's easy then to [assemble] a house in a few days." Mortar is then applied to the exterior, adding weight and structural stability and giving it the appearance of a typical Puerto Rican home made from concrete blocks and cement.

Astrid Diaz's new modular home is on display. Right now, it's just a prototype ― a few walls and a roof assembled using a lightweight, economical and durable building material: polyurethane foam. Greg Allen/NPR

Diaz has designed one, two and three bedroom versions of her modular home, including traditional Puerto Rican features. "We like cross-ventilation, natural illumination. We like the balcony," she says. "With the new building technology, we can build it rapidly and ecologically."

An added feature Diaz offers is an "eco-capsule" — a cistern for capturing rainwater with attached solar panels, batteries and a wind generator.

And because the ability to expand homes is important to people in Puerto Rico, Diaz designed her homes to be able to do that, too, with additional rooms and even a second story. Diaz says traditional homebuilding led some homeowners to leave steel reinforcing columns exposed on the roof to make it easy to add a second floor later. "After years, the corrosion affected the structural stability of those homes," she says.

That's one reason why many homes collapsed in the storm but the new modular homes won't have that vulnerability, she says. Diaz says her homes will comply with Puerto Rico's new building codes, which require construction to be able to withstand wind speeds up to 184 miles per hour and higher, depending on the location.

She has two modular homes going up soon on the island of Vieques, the first of what she hopes will be a new generation of affordable, hurricane-proof homes for Puerto Rico.

For more information on Gulf Concrete Technology’s (GCT) Insulated Concrete Panels, review their Technical Evaluation Report (TER) on the DrJ Certification website. DrJ Engineering is a civil engineering firm that is an ISO/IEC 17065 accredited product certification body through ANSI Accreditation Services. DrJ has provided many innovative companies with engineering and related services. If you have a new product to bring to market, contact DrJ today.


Cameron Ashley Opens Two Distribution Centers in Las Vegas, Houston

Wed, 2019-07-17 19:07

Cameron Ashley Building Products recently announced the opening of two new building products distribution center in North Las Vegas and Houston. Both distribution centers will provide sales, marketing, merchandising, and local inventory support for roofinginsulation, and other building materials. Each facility represents a brand new market opportunity for Cameron Ashley.

These distribution centers provide both new opportunities and the ability to better serve current customers in both locations.

These facilities represent the fifth and sixth centers the Greensville, S.C.-based company has opened in 2019. The company previously opened distribution centers in Rocky Mount, N.C., and Macedonia, Ohio, in January, a location in Columbia, S.C., in February, and a distribution centers in Phoenix, Ariz.

Cameron Ashley, a company of Pacific Avenue Capital Partners, is a distributor of roofing, insulation, gypsum, and other specialty building products with more than 35 distribution centers nationwide. In addition to the six distribution center openings in 2019, Cameron Ashley also announced its acquisition of St. Louis-based distributor Warrior Building Products in late January.


What Are Your Thoughts on These Inspection Photos?

Wed, 2019-07-17 15:52
Building Science

Every now and then our staff gets involved in inspections, where the photographs taken tell a very interesting story. Please review the twelve photos that follow and provide us back with your thoughts regarding:

  1. What do you think happened to cause this kind of degradation?
  2. What are your observations with respect to:
    1. Window installation performance
    2. Flashing performance
    3. WRB performance
    4. OSB sheathing performance 
    5. Foam sheathing performance
    6. Wood structural member performance
  3. What other observations come to mind?

Please share your perspective. There are more pictures, so it is likely that, if observations are sent back, there is more insight that can be provided. Our goal in asking is to not taint points of view, but rather seek top of mind thoughts that can be used to provide additional commentary.

Photo 1 Photo 2 Photo 3 Photo 4 Photo 5 Photo 6 Photo 7 Photo 8 Photo 9 Photo 10 Photo 11 Photo 12

  Previous   Next

For more information on thermal performance, moisture protection and vapor barriers, visit


National Building Code of Canada Recognizes XPS Aged R-Values

Tue, 2019-07-16 10:57
Building Codes

Thermal insulation materials are critical to a building's design and its ability to reduce energy consumption.

In 2017, the ULC Standards Committee on Thermal Insulation Materials and Systems approved an updated fifth edition of the CAN/ULC-S701.1, Standard for Thermal Insulation, Polystyrene Boards. This standard specifies the requirements for rigid expanded polystyrene (EPS) and extruded polystyrene (XPS) insulation.

Following the S701.1 standard update, the Canadian Commission on Building and Fire Codes has recognized the Fifth Edition as the new reference document for EPS and XPS insulation in the interim revision to the 2015 National Building Code of Canada. Now that NBC 2015 recognizes S701.1, Canadian provinces can adopt the requirements in Provincial jurisdictions. Three provinces, Alberta, British Columbia, and Saskatchewan have already adopted the NBC 2015.

Two changes to the Fifth Edition were significant for providing greater clarity on thermal performance. First, this edition removed the conditioned thermal resistance requirements for XPS in favor of requiring the Long-Term Thermal Resistance (LTTR) determined using CAN/ULC-S770-15, Standard Test Method for Determination of Long-Term Thermal Resistance of Closed-Cell Thermal Insulating Foams.

This test method is used to determine the LTTR for products that contain a cell gas (other than air) which diffuses over time, i.e., foam plastic insulation like XPS that are subject to aging. CAN/ULC-S770 predicts the 5-year aged R-value (equal to the 15-year time-weighted average R-value). In contrast, EPS insulation, which contains only air in its closed cell structure and therefore does not age, continues to have its R-value determined by ASTM C518.

The second change mandated that the LTTR, rather than the initial R-value or conditioned R-value, be marked on the XPS insulation products for greater clarity for consumers and designers. These two changes are consistent with the requirements of the building code to use LTTR values in energy calculations for foam plastic insulations that retain a blowing agent other than air for a period longer than 180 days.

To characterize the effective R-value of polystyrene insulation considering the effects of aging and conditions of application, the EPS Industry Alliance has recently published a paper, Polystyrene Foam Insulation in Long-Term Building Applications, Effective R-Values, that provides a method to estimate R-value by accounting for these factors.

R-value test standards, specifications, and labeling requirements are critical to providing consumers and designers with information necessary to predict the thermal performance of the insulation product. Without an understanding of aged R-value, consumers, building designers, and specifiers will overestimate the insulation's performance and underestimate the energy consumption of the building over its lifespan.

The EPS Industry Alliance is the North American trade organization representing the expanded polystyrene industry and focuses on the advancement and innovation of EPS products in construction and packaging.


EIMA Takes Texas Back in Major Victory

Tue, 2019-07-16 10:51
Building Codes

Texas Governor Greg Abbott officially signed H.B. 2439 into law on June 14, 2019. This legislation, which received overwhelming bipartisan support in both the Texas House of Representatives and the Texas Senate, prohibits local governments in Texas from mandating the use of only specific products, and it will allow the use of products and materials permitted in current national building codes. The law now goes into effect on September 1, 2019.

For the better part of a decade, EIMA had been working on a case-by-case basis on EIFS prohibitions and restrictions in Texas as they came to the association’s attention. On multiple occasions, EIMA offered to its local allies educational services, tools and advice on how to combat ordinances, and gathered information on efforts by other competing interest which favored a limiting the number of building materials and products.

In early 2019, after a great deal of research and study on the situation in Texas, EIMA launched the “Take Back Texas” initiative to overturn the 220 plus restrictions against the usage of EIFS. One of the steps of the initiative was to partner with other interested parties, which is where the big break occurred.

Shortly after the initiative launched during the 2019 EIMA Annual Meeting in Houston, Texas, EIMA became an active participant in a coalition seeking to overturn all of these prohibitive codes and ordinances in a sweeping manner. The effort included the Texas Association of Builders, Safe Building Materials Association of Texas, and many other leaders in the building industry. The coalition’s efforts led to the introduction of H.B. 2439 by Rep. Phelan in the Texas House of Representatives, which was filed on February 25, 2019.

“This is one of the single biggest victories our industry has seen in years,” said EIMA President Peter Daechsel, who is a Manager of BASF Wall Systems. “Thanks to a large effort from several in the construction and building industry, the 220 plus restrictions against our industry are no more.” The bi-partisan legislation was approved by an overwhelming vote of 124-21-2 in the Texas House of Representatives, and an equally significant margin of 24-5 in the Texas Senate. Texas represented one of the many areas that EIMA has been spending resources to overturn restrictive ordinances against the EIFS industry.


This House Is Built to Stare Down a Hurricane

Tue, 2019-07-16 10:31
Building Science

Breezy Point is beautiful in the summertime, a quaint neighborhood sitting on a slim peninsula that juts out into the Atlantic just south of New York City.

In a storm, though, that dreamy setting can become a nightmare.

Home designed by Azaroff in Breezy Point, Queens. Photographer: Victor J. Blue/Bloomberg

Breezy Point was devastated by Hurricane Sandy in 2012. Flooding, high winds and fires destroyed more than 300 homes, with many more left damaged and unlivable. Now, seven years later, architect Illya Azaroff has designed and built a home there he says can withstand a storm even more powerful than Sandy, "maintaining operation, even if all else fails.’’

Welcome to the home of the future in a time of climate change. As weather gets wilder and less predictable, firms that design, construct or improve housing with storm safety and resiliency in mind are increasingly in demand, said Matt Belcher, a builder in tornado-prone St. Louis. It’s a powerful marketing message that cuts across the political divide, he said.

“The frequency and severity of the storms are increasing," said Belcher, who builds houses designed to withstand 140 mile-an-hour winds. "Whether people credit it to climate change or think it’s cyclical, it doesn’t matter if your house is destroyed. Either way, resiliency applies.”

A Home Built for Extreme Weather

Strategies to increase the chances of surviving climate disasters

In 2008, the Insurance Institute for Business & Home Safety, an industry research group, created a set of construction standards that generally exceed local building codes, certifying that a home is likely to survive hurricane-force winds and rain.

The needle barely moved on the number of homes meeting the designation in a handful of hurricane-prone states from 1,122 in 2008 to 1,638 in 2014. By 2018, the number jumped ten-fold to 11,031 homes, and it’s moved to 12,530 in the first four months of 2019.

Building Strong

Fortified homes in hurricane-prone U.S. states soar

Source: Insurance Institute for Business & Home Safety

The "fortified" designation is provided by trained evaluators primarily based in Texas, Florida, the Carolinas and Alabama, though the institute is now expanding the numbers of states they serve. In some areas, the designation can help homeowners with insurance and renovation costs.

"When the consumer has a different perception of the risk, it changes the demands they make on home builders," said Roy Wright, the group’s leader and a former head of risk mitigation at the Federal Emergency Management Agency. "The home building industry will respond to the market, they always do."

A resident looks over damage in Breezy Point, Queens on Oct. 31, 2012. Photographer: Scott Eells/Bloomberg

The Breezy Point design by Brooklyn-based Azaroff, who also serves as the New York disaster coordinator for the American Institute of Architects, keeps Sandy’s devastation in mind, from the bottom up:

  • The house is elevated more than 3-feet above average flood elevation, with vents that let flowing water easily escape underneath the house.
  • The walls and floor are made with concrete-filled forms made from polystyrene and recycled plastic that can withstand driving rain and 300-mile per hour winds.
  • It has fire-resistant fiber cement-board siding, and safety glass in the windows can withstand a 9-pound piece of wood flying at 34 miles per hour.
  • And the roof is held in place with ultra-strong connectors.

Flood vents in the solid concrete foundation. Photographer: Victor J. Blue/Bloomberg

Cost remains key for homeowners. The hurricane-strong house, as Azaroff has labeled it, is about 7% to 9% more expensive to build. But with energy and insurance savings, the upgrades should pay for themselves in 8-10 years, according to Azaroff.

While the Breezy point house is built to withstand hurricanes, architects elsewhere face other issues. Texas, Oklahoma, Kansas and Nebraska are the center of a region sometimes called Tornado Alley, and other times known as Hail Alley. Extreme weather there can can mean violently rotating winds that move in excess of 110 miles per hour.

Q4 Architects Inc., a Canada-based group, has designed a home that will not only keep residents safe during a tornado, but allow them to live at home for months, even if basic services are cut off.

At the house’s center is a concrete and steel reinforced space that includes the kitchen, bathroom, laundry and an emergency supply closet. There’s a cistern that captures rainwater and filters it, solar panels for electricity, a sun tunnel that can be opened or closed for natural light and Murphy beds.

A tornado can destroy a home in four seconds, said Jason Sampson, an architect at Canada-based Q4. “The initial ideal was to ensure some sort of comfortable living situation while disaster relief was put into place,’’ he said. “This could take months, so let’s make sure they have the right systems in place to live there."

Concrete and steel-reinforced safe room in Tornado-alley design by Q4 Architects Inc. Q4 Architects Inc.

Rima Taher, a civil and structural engineer who teaches at the New Jersey Institute of Technology, has published the textbook “Building Design for Wind Forces.” The strategies behind recent improvements in housing resiliency can be attributed to improved building codes based on research in wind engineering that started back in the 1960s, she said.

"We have more knowledge in this field now, and building codes and standards are stronger," Taher said by telephone.

Taher frequently gets calls for advice, she said, noting that a couple of important things to focus on are roof design and strong connections between walls, between the walls and the roof, and between the structure and its foundation. Taher advises "hurricane ties," or straps, to join the roof tightly to walls, and says roofs should be designed with multiple slopes with overhangs limited to less than 20 inches.

"The roof can be the first thing to go," she said.

Architects and builders are searching out materials designed for every environment, said Wright, the insurance institute chief executive officer. The group tests home designs in a giant wind tunnel that can simulate hurricanes, rain, hail and flying fire embers, he said.

Products made by some of the world’s largest businesses for years are increasingly coming into play, he said, as builders and architects move to meet consumer demands. A DowDupont Inc. roof membrane that keeps the indoors cooler is being tested in brutal heat in India. LafargeHolcim Ltd. makes a lightweight concrete cladding that was used on a shoreline museum in Miami to add strength to window casings and walls.

While few of these materials are new, they are more frequently being experimented with in designs for new homes in storm-prone areas.

But it’s not just new houses being worked on with extreme weather in mind. Older houses on the East Coast offer other opportunities for builders. In the Carolinas and on New York’s Long Island, local contractors have raised hundreds of houses six-to-eight feet higher within the past few years, taking advantage of government programs that popped up after major hurricanes.

Mike Rom’s company, Long Island House Lifting, now raises 45 to 50 homes a year at a cost of between $150,000 and $300,000 apiece.

In the wake of Hurricane Sandy, he said, “every other house is up in some neighborhoods." But it’s not just the big storms that are a problem, according to to Rom. Shoreline areas that used to see street flooding at most two or three times a year now see it monthly, he said.

Billy Ward, co-owner of AABC House Moving in Camden, South Carolina, used to raise only one or two homes a year. That’s changed in the wake of hurricanes Matthew, Irma and Florence in 2016, 2017 and 2018.

“We all talk about it," Ward said. “How things have gotten a lot worse."


Builder Creates a Home Out of 612,000 Plastic Soda Bottles

Tue, 2019-07-16 10:14
Building Science

Here's a new use for those plastic soda and water bottles flooding the ocean and sitting in landfills for years: home construction. 

JD Composites, the Canadian homebuilder built a three bedroom house in Nova Scotia that is made out of 612,000 plastic soda bottles.

Exterior of home made from plastic bottles (JD Composites)

The plastic was melted and injected with gas to make the 15 centimeters think plastic walls. According to reports, the material provides better insulation in the summer and winter, are resistant to moisture and mildew and enable a house to be built in days rather than months. 

Even more appealing, at least to homeowners living in hurricane areas, is its ability to withstand extreme winds.  JD Composites sent a sample of its plastic walls to be certified for hurricane resistance. It was put through the paces, even what a category 5 hurricane would feel like.  The plastic panels were able to stand up to wind speeds up as much as 326 miles per hour.  The walls could withstand even stronger winds. The company said the testing machine maxed out and the walls were still in one piece. 

While this house costs about $400,000 to erect, it is expected to have fewer issues down the road because the material is so durable. That could appeal to some homebuyers who are already spending around $400,000 for new construction. JD Composites, which operates in the boat building industry, said it intends to put the house up for sale but if there are no buyers it will list it on AirBNB. 

Developers Race to Develop Hurricane Proof Structures 

For years home builders and construction companies have been trying to develop homes that can withstand the hurricane season which has increasingly gotten worse in the past few years. One just needs to look at hurricane Maria in Puerto Rico for evidence.  That category 5 hurricane decimated the island in September of 2017. 

With the worst Atlantic hurricane season top of mind, architects and urban planners have been working hard to develop cities that can stand up to hurricanes.  In late 2017 architect Koen Olthuis teamed up with a housing startup to develop a hurricane proof house, that ditches land in favor of an aquatic location. The luxury accommodation concept is designed to float on close-to-shore waterways like bays and rivers.

Meanwhile, in the UK Baca Architects and Floating Homes are working on a series of floating homes along London's canals. The building would house as many as 7,500 people in need of homes. The structures would be prefabricated and dropped into the site.