Energy Efficiency and Building Science News

Sika Interested in Parts of BASF's Construction Chemicals Business

Wed, 2019-03-06 18:05
Building Science

Switzerland’s Sika would be interested in buying some parts of BASF’s construction chemicals business but has ruled out bidding for the whole business, Chief Executive Paul Schuler told Reuters on Friday.

The Swiss chemicals maker is still awaiting a sales pack from bank Goldman Sachs which has been appointed by BASF to oversee the sale of the business which could carry a price tag of up to 3 billion euros ($3.4 billion).

Schuler said Sika would be interested in parts of BASF’s business, for example its sealants, flooring and mortar units.

But competition concerns means Sika would not launch a bid for the whole business, he said.

“We would have a look at it,” Schuler said. “BASF have some fantastic businesses in there, they have a lot of interesting things which we would pick up if we could.”

“But buying the whole thing is out of the question.”

Funding a deal would not be a problem for Sika, which is mainly concerned about an overlap between the two companies business in concrete admixtures, used to waterproof or strengthen building projects.

In some markets a combination of Sika and BASF’s concrete admixtures businesses would have a market share of up to 80 percent, meaning a tie-up could fall foul of market regulators.

Sika would instead wait on when and how BASF decided to dispose of the business, Schuler said.

One possibility could be Sika teaming up with other industry players, who would divide the business after buying it.

Tips for Creating an Effective Insulation and Air Barrier Plan

Wed, 2019-03-06 17:56
Building Science A complex house demands a careful insulation and air-barrier plan

Building this net-zero house relies on a strategy of energy conservation. This includes blanketing the building with interior and exterior insulation and installing a continuous air-seal around the shell of the building. This thermal envelope dramatically reduces the demands of heating and cooling so they can be met with a modest PV solar array.

To achieve this on a complex design, with multiple forms and intersection points, means every assembly and critical connection is designed, drawn out, and included in the architectural plans for the builders to follow.

To air-seal, they used a broad range of Dorken Delta tapes and membranes that are compatible with one another, and then insulated the house with Rockwool insulation using both rigid and batt forms. For installation, they relied on Stanley FatMax tape measures to fit and fill all the complexities of the design.

In the mechanical pit, or traditionally poured foundation, the concrete is the air barrier, but it needed both insulation and a vapor barrier. Beneath the slab they installed 5 in. of  Rockwool ComfortBoard insulation for R-21 and Delta-MS dimple membrane as the vapor barrier.

The poured concrete walls have 4 in. of ComfortBoard on the interior that meets the subslab insulation for continuous thermal break. Inboard is an additional R-23 of Rockwool batts in a framed 2×6 wall, with a layer of Delta-Sd-Flexx adaptive, vapor-permeable membrane that has a taped connection to the dimple board under the slab.

At the top of the wall, the membrane laps onto the Delta-FL dimple membrane that is the vapor barrier over the pan-deck slab. The slab is then insulated with R-15 ComfortBatts between sleepers plus a layer of R-30 and a layer of R-23 batts installed in the TJI bays that bring the floor system to R-68.

On the walls, the plywood sheathing is covered with Delta-Vent SA, a vapor-open self-adhering weather-resistant barrier that laps down and is sealed to the foundation walls and curbs to continue the air barrier from the foundation.

The walls are insulated with R-23 ComfortBatts on the inside­ with two offset layers of 2-in. ComfortBoard on the exterior for an R-39 wall assembly.

On the roof, the plywood sheathing is the air barrier.  All the seams are taped with Delta-Multi-Band, including the edge transition from roof deck to walls.  This, like all penetrations through the envelope at any stage of the build, are carefully air-sealed for a continuous air-barrier.

Once air-sealed, Delta-Vent S—a tough, vapor-permeable waterproof underlayment—was installed, before the 5-in.-thick rigid-board Rockwool called TopRock DD that will allow the standing-seam metal to roof to be installed directly over the insulation without additional sheathing. Combined with the insulated deep rafter bays below the lid of the house makes a cozy R-80.

Heating, air conditioning, and more

With the insulation and air-sealing work complete, the combination of products, critical design work, and attention to detail brought this house in at 0.6 ACH50—which means today, with these Passive-house-level numbers, it’s one of the tightest homes in California.  This means the builders can rely on the roof-mounted PV array to power small, very efficient air-source heat pumps used for space heating and cooling.

The compressors are mounted to the outside of the building and sheltered by the pan deck above, as is the compressor for the heat-pump water heater that will dump cool air into the atmosphere rather than in the home.

Mitsubishi heat pumps were used because of their efficiency. The hyper-heat models operate at 100% efficiency down to 5°F, well below the typical winter conditions this house will see.

Inside the home, the designers selected locations out of the line of site from the main living areas to mount the heat-pump distribution units. On the second floor, one unit is mounted on the backside of a doorway, in the hallway leading to the master bedroom, and on the first floor, another is placed over a closet in the mudroom. The third and final unit is tucked away above the cabinets over the refrigerator built-in.

Other mechanicals will include a washer and dryer. Here, a Dryer Box was installed so the dryer can be pushed flush against the wall without damaging the hose or compromising the air flow.  The warm moist air will then travel to the outside of the building where a dampened DryerWallVent will minimize air intrusion.

Video: Understanding Air and Vapor Barriers

Wed, 2019-03-06 17:44
Building Science

From Siga headquarters in Switzerland, Matt Risinger explains the science of controlling both air and vapor in buildings. The elegance of this video comes, in part, from Matt's clear way of summarizing, and prioritizing, the control strategies available to builders. He stands here on the shoulders of giants, namely Joe Lstiburek, whose work Matt has been a diligent student of for many years. He doesn't hide this, but he also provides a helpful complement to his mentor's work by succinctly capturing the key principles. It's a sound introduction to the dynamics of heat and moisture flow through building assemblies.

If you're interested in delving further, this video offers a helpful introduction to a number of JLC features, as well:

Matt's science lesson is also artfully woven with a look inside Siga, the Swiss maker of tapes and membranes designed specifically for controlling air and vapor in building assemblies. This "inside look" adds a layer of interest for veterans and novices of building science alike.

About the Author

Matt Risinger

Matt Risinger owns Risinger & Company in Austin, Texas. He is a frequent contributor to JLC, where you can find selections from his blog and his YouTube channel.

Wall Panel and Insulation Combo Streamlines Installation

Wed, 2019-03-06 17:36
Building Science

Hunter Panels, in partnership with Covestro, is bringing time- and cost-saving technology to the residential construction market. Their first integrated residential wall construction advancement —PUReWall™—is a smart-solution for the skilled labor shortage. The panelized wall assembly reduces jobsite labor, shortens build time and cuts homeowner energy costs all while ensuring a high-quality system.

The partnership between Covestro, one of the world-leading producers of high-performance polyurethane raw materials, and Hunter Panels, a division of Carlisle Construction Materials, the largest domestic producer of SPF and polyiso, is paving the way forward in residential wall construction.

PUReWall™ by Hunter Panels is a panelized wall assembly with a proprietary combination of PUReWall™ Polyiso continuous insulation on the exterior and PUReWall™ Structural Foam (SPF) in the wall cavity. It is pre-assembled with both products and 2”x4” studs, up to 24” on center, in a controlled panelization facility, and is offered as a complete solution to streamline installation. As an added benefit, the system’s continuous insulation and taped joints allow it to function as a weather-resistant barrier, eliminating the need for house wrap.

“We hear homebuilders and forecasters alike talk about the continued labor challenges the industry is facing,” said MacGregor Pierce, PUReWall™ product manager. “By joining forces with Covestro, we’re able to combine two products with a proven track record to alleviate jobsite demands. PUReWall™’s ability to simplify construction, combined with the opportunity to make continuous insulation a standard energy-saving building practice, make it a perfect solution for both today’s custom and production homes.”

PUReWall™ panels will be on display at the 2019 PCBC in San Francisco, California, May 30-31. PUReWall™ samples and product experts will be on hand at the show to explain the assembly in more detail, talk about homes already using the product, and share how builders can begin using this innovative panelized wall assembly to meet their construction needs. 
For more information please visit our website at Hunterpanels.com/purewall or follow us on LinkedIn, Facebook, or Twitter for updates and project highlights.

About Hunter Panels 
Hunter Panels, owned by Carlisle Construction Materials, produces Hunter Xci wall insulation and Hunter roof insulation. The company is headquartered in Portland, Maine, with seven state-of-the-art polyiso manufacturing plants in New York, Pennsylvania, Florida, Illinois, Texas, Utah, and Washington. For more information, visit http://www.hunterpanels.com or call 888-746-1114.

About PUReWall™ 
PUReWall™ is a wall panelization system developed by Covestro LLC. Designed for use in residential construction, it replaces traditional exterior sheathing with a combination of polyisocyanurate (polyiso) continuous insulation on the exterior and spray polyurethane foam (SPF) in the wall cavity.

APA - Allowable Design Values - IRC Wall Bracing = 175 PLF

Wed, 2019-03-06 17:26

APA provided a report, which evaluated the available IRC compliant braced wall line test data, for the National Institute of Building Sciences' Building Seismic Safety Council. This data was then compiled, organized, and publicly reported.

Report to BSSC Bracing Committee

May 2007
©2007 APA – The Engineered Wood Association

The APA report states the following purpose:

A REVIEW OF LARGE SCALE WOOD STRUCTURAL PANEL BRACING TESTS

By Zeno Martin, P.E., Tom Skaggs, Ph.D., P.E., Ed Keith, P.E., Borjen Yeh, Ph.D, P.E.
APA – The Engineered Wood Association

1. OVERVIEW AND PURPOSE

This report summarizes available large scale test data for wood structural panel conventional construction wall bracing. Several 4-ft long wall tests are included, but the majority of test data is taken from tests where wall lengths are at least 12-ft. The purpose of assembling this information is to help evaluate and determine the strength of wood structural panel wall bracing.

This APA-BSSC report documents the OSB tests in a number of tables. Table 1, copied from this report, documents testing of wall assemblies with IRC-compliant OSB braced wall line segments. For this sampling of tested wall assemblies, representing single story walls using traditional anchor bolt restraint, OSB (i.e. wood structural panels (WSP)) provided an average ultimate lateral resistance capacity of 351 plf with no interior gypsum wallboard (GWB) applied. This means that OSB has an IRC allowable design capacity of 175 plf (351 plf divided by 2 per Special Design Provisions Wind and Seismic (SDPWS) section 4.3.3).

Summary of test results for isolated wood structural panel wall bracing without gypsum finish.

Row
#

Description

Load at
0.5% drift

Peak Load

Total
Length of Wall

Total Length of Bracing

Gyp

Bracing

Test Protocol

Segment Width

Test #
in Ref.

Reference

(plf)

(plf)

(ft)

(ft)

--

--

--

(ft)

--

 

 

Average =

187

351

 Allowable lateral resistance design capacity is 175 plf.

Minimum =

115

180

Maximum =

307

582

Table 1: Large scale wall bracing tests APA-BSSC report. See appendix B for the full table.

Additionally, the APA-BSSC report shows that IRC compliant OSB braced wall lines with GWB attached, in accordance with the IRC (i.e. screws spaced 16:16), provides an average ultimate lateral resistance capacity of 383 plf. This means that OSB with GWB has an IRC allowable design capacity of 192 plf (383 plf divided by 2 per SDPWS). Please review Table 2.

Summary of test results for isolated wood structural panel wall bracing with gypsum finish.

Row
#

Description Load at
0.5% drift Peak
Load Total
Length of
Wall Total
Length of
Bracing Gyp Bracing Test
Protocol Segment
Width Test #
in Ref. Reference   (plf) (plf) (ft) (ft) -- -- -- (ft) --   Average = 255 383 Allowable lateral resistance design capacity is 192 plf.

Table 2: Isolated bracing with GWB APA-BSSC Report. See appendix C for the full table.

The APA-BSSC report of IRC compliant braced wall line assembly tests suggest that the application of GWB is only adding 32 plf (383-351= 32).

The Structural Building Component Research Institute (SBCRI) also undertook IRC code compliant OSB braced wall line testing without interior GWB. This testing yielded the results¹ found in Table 3.

Full-Scale Monotonic Lateral Wall Testing in a 12' x 30' Building: 3/8" WSP 6' from End Wall, No Interior GWB (with Load Path to the Foundation) 2 1/2" x .131 Nail 6:12 371

Allowable lateral resistance design capacity is 187 plf.

Note  [1] These are proprietary tests and proprietary intellectual property, which is being provided herein to increase decision-making knowledge regarding IRC compliant braced wall line performance

374

Table 3: SBCRI testing of IRC Compliant (i.e. anchor bolt hold downs) OSB Braced Wall Lines. See appendix D for full table.

In the IRC code compliant OSB braced wall testing, the SBCRI test minimum was 334 plf and averaged 374 plf. This testing confirms the APA-BSSC report generated OSB capacity of 350 plf. Please see appendix A for photos of the SBCRI testing.

30 foot Wall Experimental Testing to Determine Contribution of 1/2" GWB 16:16 PLF on a 30' basis to define GWB contribution Contribution of GWB 7/16" 8d 6"/12" IRC Test 4_1 WSP@ each corner; full roof dead; NO wall gyp; ultimate ave of two walls; anchor bolts 114   7/16" 8d 6"/12" IRC Test 4_1 2- WSP@ each corner; full roof dead; 30' wall gyp; ultimate ave of two walls; anchor bolts 215 102 7/16" 8d 6"/12" IRC Test 2; WSP 2 @ 6' from corner; full roof dead; NO wall gyp; ultimate ave of two walls; anchor bolts 110   7/16" 8d 6"/12" IRC Test 2; WSP 2 @ 6' from corner; full roof dead; 30' wall gyp; ultimate ave of two walls; anchor bolts 251 141

Table 4: SBCRI testing of IRC Compliant (i.e. anchor bolt hold downs) OSB Braced Wall Lines with Interior GWB (screws 16:16)

Table 4 provides SBCRI testing of IRC compliant OSB braced wall line with interior GWB installed. The OSB testing yielded a 102 and 141 plf contribution for the GWB when screws are spaced at 16:16. Testing was also performed on proprietary engineered fiberboard sheathing where the GWB contribution was 110 plf. SBCRI testing confirms the APA-BSSC report generated capacity of 383 plf when OSB has interior GWB attached.

Given the testing performed, and to be reasonable, SBCRI has used an interior GWB contribution of 100 plf, when attached using screws at 16:16. This addition is for code compliant IRC braced wall lines when OSB is applied as isolated panels (i.e. 4x8 sheet in corner or 6 feet from corner).

Given the foregoing set of undisputed facts, IRC code compliant walls are using a systems effect factor of roughly 1.8 for walls sheathed with OSB only. (600/334 using the minimum OSB performance to be conservative is 1.8).

Additionally, IRC code compliant OSB walls with interior GWB attached are using a systems effect factor of roughly 2.19 (840/383) if APA-BSSC report generated numbers are used and 1.8 (840/450) for walls tested by SBCRI. It is an SBCRI opinion that 450 plf most accurately reflects the lateral resistance for a braced wall line sheathed with OSB and interior GWB (840/434 as the minimum OSB performance to be conservative is 1.9).

For proprietary products that compete with OSB sheathed walls, it is critical for them to be able to compete on a level-playing field basis. SBCA created an IRC code change proposal to reflect APA and SBCRI testing. This 2013 code change proposal, which provides what SBCRI believes are reasonable “standard equivalency factors”, is provided in Table 5:

This item is on agenda for individual consideration because a public comment was submitted.

Public Comment:

Larry Wainright, Qualtim, representing Structural Building Components Association, requests Approval as Modified by this Public Comment.

Modify the proposal as follows:

TABLE R602.10.4.4
SIMPLIFIED SHEAR VALUES FOR WIND LOADING BRACED WALL PANELS

Sheathing
Material
Bottom plate connection to foundation Fastener Fastener Spacing Any Species Stud Framing Tested Capacity System Effects Factor IRC Lateral Design Capacity 3/8", 7/16" or 15/32" WSP @16" and 24" o.c framing Anchor bolts in accordance with code requirements 6d (2" x 0.113" nails) or 8d (2 1/2 x 0.131") 6:12 335 350 1.80 600 3/8", 7/16" or 15/32" WSP @16" and 24" o.c framing (with 1/2" gypsum on interior face of wall. Anchor bolts in accordance with code requirements 6d (2" x 0.113" nails) or 8d (2 1/2 x 0.131") nails and Types S or W drywall screws 6:12 WSP & 16:16 for GWB 465 450 1.80 840

a. The lateral design capacity of braced wall panels is based on full scale wall assembly tests using the minimum restraint provisions of the IRC, further adjusted by the partial restraint/systems effect factor.

Note: the change from 335 to 350 plf for the walls without GWB changed the system effect factor to 1.7 and similarly for walls with GWB so that a common “standard equivalency factor” could be used. This change accurately reflected tested performance well.

Table 5: Proposed 2013 IRC Code Change Proposal table showing “standard equivalency factors”, which APA acknowledges exist in APA’s bracing spectrum analysis which can be read in the APA-BSSC report.

APA, the American Wood Council (AWC) and NAHB vigorously opposed this code change proposal, and the IRC committee denied it.  The  APA-BSSC report stands undisputed by APA and confirmed by SBCRI testing, which means that the testing is correct and the IRC still has “standard equivalency factors” embedded in the building code and codified into law.

On January 3, 2013, SBCA attended a meeting with APA to address OSB design values and “standard equivalency factors”, which clearly exist in the IRC. Mr. Ed Elias, president of APA attended the meeting and responded with via letter to SBCA, where he discusses the concept of “standard factors” for “product equivalency.” Specifically, he wrote:

"APA staff has reviewed the information that was shared with us and we have the following comments and concerns:……….

We believe that a major goal for the SBCA position is to provide a cost-effective engineering solution to their membership and as such this goal serves the SBCA membership well. However, by establishing standard factors in which product equivalency or system performance are applied generically, an unintended consequence may be that non-wood products (e.g. foam sheathing) gain an advantage and supplant traditional OSB market share.

This is not in our Association member’s best interests."

…………

We fully understand APA’s desire to have a competitive advantage codified into the IRC as the law of the land. All sheathing manufacturers would like this to be the case for their products.

SBCA has provided, and will continue to provide transparency to the market with respect to “standard equivalency factors.” These factors should be used to establish IRC compliant OSB equivalency for any braced wall line product including OSB.

Knowledge of the APA-BSSC report test data and how OSB braced wall line lateral resistance is codified provides code officials and manufacturers with the knowledge and tools needed to use IRC “standard equivalency factors.” The goal of any free, fair and competitive market is to use accurate design values and any associated “equivalency factors” so that a level playing field is provided. In 2007 APA acknowledges that this should be done in their APA-BSSC report and bracing spectrum analysis.  

Related Articles and Information

OSB as a Raw Material (background information on OSB testing and engineering analysis)

Appendix A

Photos of SBCRI OSB Testing

Appendix B

Table 1: Large scale wall bracing tests- APA- BSSC Report

Summary of test results for isolated wood structural panel wall bracing without gypsum finish.

Row
#

Description

Load at
0.5% drift

Peak Load

Total
Length of Wall

Total Length of Bracing

Gyp

Bracing

Test Protocol

Segment Width

Test #
in Ref.

Reference

(plf)

(plf)

(ft)

(ft)

--

--

--

(ft)

--

 

25

4-ft wall isolated bracing segment

131

180

4

4

No

Isolated

mono.

4

718&719

Simpson, 2007a

30

20-ft wall isolated bracing segments, "Cabo"

136

204

20

8

No

Isolated

mono.

4

713&714

Simpson, 2007d

19

4-ft wall isolated bracing segment

210

225

4

4

No

Isolated

SPD

4

7

APA, 2006

31

20-ft wall isolated bracing, "Cabo" with 2x10 rim joist

158

238

20

8

No

Isolated

mono.

4

721&722

Simpson, 2007d

43

3D - NW: Cabo, NE: Cabo, SW: Cabo, SE: Cabo (+45)

177

256

20

32

No

Isolated

mono.

4

2006744

Simpson, 2007o

47

3D - NW: Cabo, NE: Cabo, SW: Cabo, SE: Cabo (-45)

168

265

20

32

No

Isolated

mono.

4

2006732

Simpson, 2007s

28

20-ft wall isolated bracing, "IRC Center"

115

294

20

4

No

Isolated

mono.

4

702&709

Simpson, 2007c

40

3D - W: Cabo, E: Cabo, N: Cabo, S: Cabo (90)

222

363

20

16

No

Isolated

mono.

4

2006715

Simpson, 2007l

39

3D - W: IRC Center, E: IRC Center, N: IRC Center, S: IRC Center (90)

181

394

20

8

No

Isolated

mono.

4

2006700

Simpson, 2007k

32

20-ft isolated bracing segment "IRC Side"

147

401

20

4

No

Isolated

mono.

4

710&711

Simpson, 2007e

46

3D - NW: IRC Center, NE: IRC Center, SW: IRC Center, SE: IRC Center (+45)

177

420

20

16

No

Isolated

mono.

4

2007001

Simpson, 2007r

29

20-ft wall isolated bracing, "IRC Center" with 2x10 rim joist

172

467

20

4

No

Isolated

mono.

4

723&724

Simpson, 2007c

34

3D - W: Cabo, E: Cabo, N: Cabo, S: Cabo (0)

281

469

20

16

No

Isolated

mono.

4

2006716

Simpson, 2007f

38

3D - W: IRC Center, E: IRC Center, N: IRC Center, S: IRC Center (0)

219

513

20

8

No

Isolated

mono.

4

2006703

Simpson, 2007j

33

20-ft isolated bracing "IRC Side" with 2x10 rim joist

307

582

20

4

No

Isolated

mono.

4

726&727

Simpson, 2007e

 

Average =

187

351

 Allowable lateral resistance design capacity is 175 plf.

Minimum =

115

180

Maximum =

307

582

Appendix C

Table 2: APA BSSC report- Isolated bracing with GWB.

Summary of test results for isolated wood structural panel wall bracing with gypsum finish.

Row
#

Description Load at
0.5% drift Peak
Load Total
Length of
Wall Total
Length of
Bracing Gyp Bracing Test
Protocol Segment
Width Test #
in Ref. Reference   (plf) (plf) (ft) (ft) -- -- -- (ft) --   3 40-ft wall with isolated bracing 237 366 40 12 Yes Isolated mono. 4 E Dolan and Heine, 1997a 6 40-ft wall with isolated bracing 273 400 40 12 Yes Isolated SPD 4 E Dolan and Heine, 1997b Average = 255 383 Allowable lateral resistance design capacity is 192 plf.

Appendix D

Table 3: SBCRI testing of IRC Compliant (i.e. anchor bolt hold downs) OSB Braced Wall Lines

Full-Scale Monotonic Lateral Wall Testing in a 12' x 30' Building: 3/8" WSP 6' from End Wall, No Interior GWB (with Load Path to the Foundation) 2 1/2" x .131 Nail 6:12 371 Full-Scale Monotonic Lateral Wall Testing in a 12' x 30' Building: 3/8" WSP 6' from End Wall, No Interior GWB (with Load Path to the Foundation) 2 3/8" x .113 Nail 6:12 391 Full-Scale Monotonic Lateral Wall Testing in a 12' x 30' Building: 3/8" WSP 6' from End Wall, No Interior GWB (with Load Path to the Foundation) 2 3/8" x .113 Nail 6:12 402 Full-Scale Monotonic Lateral Wall Testing in a 12' x 30' Building: 3/8" WSP 6' from End Wall, No Interior GWB (with Load Path to the Foundation) 2 3/8" x .113 Nail 6:12 339 Full-Scale Monotonic Lateral Wall Testing in a 12' x 30' Building: 3/8" WSP 6' from End Wall, No Interior GWB (with Load Path to the Foundation) 2 3/8" x .113 Nail 6:12 407 Full-Scale Monotonic Lateral Wall Testing in a 12' x 30' Building: 7/16" WSP 6' from End Wall, No Interior GWB (with Load Path to the Foundation) 2 1/2" x .131 Nail 6:12 334 Full-Scale Monotonic Lateral Wall Testing in a 12' x 30' Building: 7/16" WSP 6' from End Wall, No Interior GWB (with Load Path to the Foundation) 2 1/2" x .131 Nail 6:12 414 Full-Scale Monotonic Lateral Wall Testing in a 12' x 30' Building: 7/16" WSP 6' from End Wall, No Interior GWB (with Load Path to the Foundation) 2 1/2" x .131 Nail 6:12 410 Full-Scale Monotonic Lateral Wall Testing in a 12' x 30' Building: 7/16" WSP 6' from End Wall, No Interior GWB (with Load Path to the Foundation) 2 1/2" x .131 Nail 6:12 330 Full-Scale Monotonic Lateral Wall Testing in a 12' x 30' Building: Two 3/8" WSP Panels 6' from End Wall, No Interior GWB (with Load Path to the Foundation) 2 3/8" x .113 Nail 6:12 356 Full-Scale Cyclic Lateral Wall Testing, 3/8" OSB 4' From Corner, No Interior GWB, w/o Hold-Down 2 3/8" x .113 Nail 6:12 316 Full-Scale Cyclic Lateral Wall Testing, 3/8" OSB 4' From Corner, No Interior GWB, w/o Hold-Down 2 3/8" x .113 Galvanized Nail 6:12 321

Allowable lateral resistance design capacity is 187 plf.

Note  [1] These are proprietary tests and proprietary intellectual property, which is being provided herein to increase decision-making knowledge regarding IRC compliant braced wall line performance

374

IRC Wall Bracing Testing

Tue, 2019-02-26 17:26

APA Knows IRC OSB Lateral Resistance Capacity is 350 plf & 383 plf with GWB

APA provided a report to the Building Seismic Safety Committee as follows:

The APA report states the following purpose:

This APA-BSSC report documents a large variety of wall bracing tests. Table 3, of this report, documents testing of wall assemblies with IRC compliant OSB braced wall line segments. The result is that for this sampling of assemblies, representing single story walls using traditional anchor bolt restraint, wood structural panels provide an average ultimate lateral resistance capacity of 351 plf. In other words, the allowable design capacity is 175 plf.

Table 1: Large scale wall bracing tests- APA- BSSC Report.

 

Additionally, the APA-BSSC report shows that IRC compliant OSB braced wall line segments with gypsum wall board (GWB) attached in accordance with the IRC (i.e. screws spaced 16:16) provide an average ultimate lateral resistance capacity of 383 plf. In other words, the allowable design capacity is 192 plf.

Table 2: APA BSSC report- Isolated bracing with GWB.

The APA-BSSC report of IRC compliant braced wall line assembly tests suggest that the application of GWB is only adding 32 plf (383-351= 32).

The Structural Building Component Research Institute (SBCRI) also undertook IRC code compliant OSB braced wall line testing without interior GWB this testing yielded the following results:

Table 3. SBCRI testing of IRC Compliant Braced Wall Lines -- OSB Only -- Anchor Bolts

 

In the IRC code compliant OSB braced wall testing (see appendix A for photos of the SBCRI test approach), the SBCRI test minimum was 334 plf and averaged 374 plf. This testing confirms the APA-BSSC report generated OSB capacity of 350 plf.

Table 4. SBCRI testing of IRC Compliant Braced Wall Lines -- OSB with Interior GWB (screws 16:16) -- Anchor Bolts

 

SBCRI also tested IRC compliant OSB applications with interior GWB installed. The OSB testing yielded a 102 plf contribution for interior GWB with screws sapced at 16:16. Testing was also performed on proprietary engineered fiberboard sheathing where the GWB contribution was 110 plf.  Testing confirms the APA-BSSC report generated OSB with interior GWB capacity of 383 plf.

Given the testing performed, and to be more accurate, SBCRI has used a contribution of 100 plf for the addition of interior GWB using screws at 16:16. This addition is for code compliant IRC braced wall lines when OSB is applied as isolated panels (i.e. 4x8 sheet in corner or 6 feet from corner).

It follows that IRC code compliant walls are using a systems effect factor of roughly 1.8 for walls sheathed with OSB without interior GWB attached (600/334 using the minimum OSB performance to be conservative = 1.8).

It also follows that IRC code compliant walls with interior GWB attached are using a systems effect factor of roughly 2.19 (840/383) if APA-BSSC report generated numbers are used and 1.8 (840/450) for walls tested by SBCRI. It is an SBCRI opinion that 450 plf most accurately reflects the lateral resistance for a braced wall line sheathed with OSB and having GWB attached (840/434 as the minimum OSB performance to be conservative = 1.9).

For proprietary products that compete with WSP sheathed walls, it is critical for them to be able to compete on a level-playing field basis. SBCA provided a code change proposal to reflect APA and SBCRI testing. This IRC code change proposal, which provides what SBCRI believes are reasonable “standard equivalency factors”, follows:

Table 5. Proposed table showing systems effect factors for IRC construction.

Note: the change from 335 to 350 plf for the walls without GWB changed the system effect factor to 1.7 and similarly for walls with GWB so that a common “standard equivalency factor” could be used. This change accurately reflected tested performance well.

APA, the American Wood Council (AWC) and NAHB vigorously opposed this code change proposal, and it was denied by the IRC committee.  The  APA-BSSC report stands undisputed by APA and confirmed by SBCRI testing, which means that the testing is correct and the IRC still has “standard equivalency factors” embedded codified into law.

On January 3, 2013, SBCA attended a meeting with APA to address OSB design properties and “standard equivalency factors”, which undisputedly exist in the IRC. Mr. Ed Elias, President, APA and attendee of the meeting, responded with a letter where he discusses the concept of “standard factors” for “product equivalency.” Specifically, he wrote:

"APA staff has reviewed the information that was shared with us and we have the following comments and concerns:

We believe that a major goal for the SBCA position is to provide a cost-effective engineering solution to their membership and as such this goal serves the SBCA membership well. However, by establishing standard factors in which product equivalency or system performance are applied generically, an unintended consequence may be that non-wood products (e.g. foam sheathing) gain an advantage and supplant traditional OSB market share.

This is not in our Association member’s best interests..."

We fully understand APA’s desire to have a competitive advantage codified into the IRC as law. All sheathing manufacturer would like this to be the case for their products.

SBCA has provided and will continue to provide transparency to the market with respect to “standard equivalency factors” that should be used to establish IRC compliant OSB and OSB equivalency. Knowledge of APA-BSSC report test data and how OSB braced wall line lateral resistance is codified provides code officials and manufacturers the knowledge and tools needed to use “standard equivalency factors”. The goal of any free, fair and competitive market is to use accurate design values that provide for a level playing field.  

 

Related Articles and Information
When Does 450=840? Why Not Fix It? SBCA Tried..., October 2015
APA Introduces "Standard Factors for OSB Equivalency" Concept, July 2018
OSB as a Raw Material (background information on OSB testing and engineering analysis)

Appendix A

Photos of SBCRI OSB Testing

 

 

 

 

Video: How to (Not) Ruin a Perfectly Good Wall

Tue, 2019-02-26 17:16
Building ScienceEnergy Efficiency

In this series of articles (see list below), we’ve been highlighting the benefits that continuous insulation can have in pretty much any wall design. 

But any wall, no matter how well insulated or built, will surely deteriorate if it permits water to intrude.  Keeping bulk water out is probably the most important thing that a wall does.  How this is done today is pretty simple: before rain can get to anything it can damage, it hits a continuous drainage plain and runs down until it falls off the drip edge of flashing at the bottom.  The details are important here, and to make sure that it works well, all the pieces need to be carefully integrated together.  The good news is that integrating continuous insulation and the water resistive barrier is not rocket science.  The insulation can simply be installed as found in the Department of Energy graphic Figure 1 at right.

A labor cost effective option with certain products is to use continuous insulation as its own WRB, by taping all seams and overlapping the insulation boards over the flashing (be sure to check that your insulation product is approved for this usage, and follow manufacturer’s instructions).

There are plenty of water control resources available at continuousinsulation.org.  A good place to start would be the water resistive barrier topical library.  The video below explains the importance of the WRB:

 

 

For additional information, please review the following articles, as well as the previous videos in this series:

Perfect Wall Articles

  1. Polyiso CI Helps Designers Achieve a 'Perfect Wall'
  2. New Wall Design Calculator for Commercial Energy Code Compliance
  3. Energy Code Math Lesson: Why an R-25 Wall is Not Equal to a R-20+5ci
  4. Continuous Insulation Solves Energy Code Math Problem
  5. Perfect Walls are Perfect, and Hybrid Walls Perfectly Good
  6. Wood Framed Wall Insulation Calculator Explained

Video Series

  1. Fear Building Envelopes No More with This Website & Videos
  2. Thermodynamics Simplified Heat Flows from Warm to Cold
  3. Moisture Flow Drives Water Induced Problems
  4. Video: How the 'Perfect Wall' Solves Environmental Diversity
  5. Video: How Important Is Your WRB?
  6. Video: A Reliably Perfect Wall Anywhere
  7. Video: The Best Wall We Know How to Make 
  8. Video: How to Insulate with Steel Studs
  9. Video: Thermal Bridging and Steel Studs
  10. Video: Better Residential Energy Performance with Continuous Insulation

Concrete Insulated Forms Used in Resilient OK Home

Tue, 2019-02-26 16:49
Building Science

With another tornado season, now just weeks away. Most of us will pay a lot more attention to the weather. But some of our neighbors won't be so worried about the warnings. A few of them have invested in a form of home construction using concrete. Its poured into the center of Styrofoam walls to make a home that's very energy efficient.

But another big benefit - a home that's as strong as a bomb shelter.

While much of it is like any other house, the big difference is in the walls.

They will be standing after any tornado, because its willed with a system called insulated concrete forms.

"FEMA rates a 6-inch steel reinforced wall at 250 mile an hour winds so an F-5 tornado will literally bounce off ICF walls," said Jerry Batey with I.C.F. Pros.

In the recent hurricanes along the gulf only cement homes survived.

The builder says he has one.

When tornadoes loom on the horizon - his home acts like the community safe room.

 

Are “Superwalls” an Effective Energy Efficiency Retrofit?

Tue, 2019-02-26 16:37
Building ScienceEnergy Efficiency

Discussing the city of Chicago’s building benchmarking initiative in 2013 Mayor Rahm Emanuel asked, “Do you check the mileage before you purchase a car? Do you check the energy efficiency of a utility before you purchase it? Do you do comparative? What is wrong with providing people information?”

Here “benchmarking” means to track and input a building’s energy consumption data and other relevant building information to quantify the building’s energy use. One important data column from the benchmarking initiative is a building’s Energy Use Intensity (EUI)—the amount of annual energy consumption per square foot. Since it is on a per square foot basis, the EUI allows comparisons of energy performance across many different categories and sizes of buildings. In the Chicago initiative, the data is then made transparent to the public to compare and contrast the energy performance of various buildings. As Mayor Emanuel put it, “Good data drives markets and innovation.”

Constructed in 1969, 5 Manhattan West in New York City was repositioned with a new façade in 2017 by Brookfield Property Partners and REX Architects. Before, top; after, bottom. (Photos: Rex Architects)

Chicago is not the first city to implement benchmarking; many cities have taken on the initiative, some as early as 2008. This transparency in the market has allowed owners, facility managers, design professionals, and many others to see how their building stacks up to that of their neighbors. Likewise, for many owners, evaluating their energy use data leads to a desire for improvement.

Parallel to the energy benchmarking movement are market repositioning projects. These are renovations performed on existing buildings to bring them up to modern trends and performance levels, with the purpose of reselling at a higher market value, or to lure new prospective tenants. As building envelope components for older façades reach their expected service life and begin to require extensive maintenance to manage water intrusion and other failures, repositioning projects with full façade re-clads or over-clads may become more desirable than performing maintenance repairs.

While generally more expensive, a full reclad or over-clad allows for a new design aesthetic in a competitive marketplace. Many of these repositioning project types include mid-rise to high-rise commercial offices and hotels, particularly for mid-century modern and post-modern buildings (1950-1990 construction) due to their age.

These repositioning projects generally try to achieve the “Mercedes” aesthetic as opposed to the “Prius” performance, meaning that a high-end appearance is desired to rebrand the building and boost value. Glass curtainwall and window wall systems are frequently specified, which allow for a modern aesthetic and full floor-to-ceiling views.

Benchmarking analysis performed by Thornton Tomasetti, filtered by high-rise office buildings > 1 million SF, and sorted by year built. Data indicates newly constructed buildings use almost as much energy as those constructed over 100-years ago. (Source: Author)

However, from an energy saving standpoint, is glass the best material for reclad projects? Although glazed systems typically allow large amounts of daylight, their insulating values are low compared to opaque wall assemblies (such as stone-clad cavity walls with insulation layers).

Analysis of the Chicago benchmarking data for office buildings leads to some noteworthy findings: when the data was sorted by the year built, it was determined that some modern buildings are using just as much energy as those constructed 100 years ago (see chart). This analysis revealed the following: Building constructed between 1902-34 showed average EUI of 81.7; constructed 1969-79, average EUI of 87.9; constructed 1980-92, average EUI of 64.6; and constructed 2001-10, average EUI of 78.2.

So how did this come to be? An answer to this conundrum can be found by reviewing changes to the building code over time. Older buildings generally utilized heavy masonry walls and had limited punched window openings. Even without the amount of insulation layers that are currently required, these low window-to-wall ratios have assisted in keeping their building EUI at a moderate level given their age. Over time, and as technology has developed, glass openings have become larger and larger, and architects have incorporated more glass into their designs.

In the 1970s a new energy code was introduced, in part in response to the oil crisis and a desire to reduce dependence on foreign entities for fuel. For the first time, limits were imposed for window-to-wall ratio on building façades. Insulated wall cladding systems were also more proactively utilized in post-modern construction. In the early 2000s, energy codes typically saw a major shift from prescriptive-based design to performance-based design (i.e., a “performance rating method”), which generally allowed fully glazed buildings to meet the code so long as they balanced the design with improved mechanical system performance or other tradeoffs.

Pre-fabricated insulated superwall system installation (Photo: Island Exterior Fabricators)

While the performance-based approach to code compliance has allowed for greater design flexibility, it is a contributing factor to increased EUI values in present-day buildings. The design of a building’s façade is one of the most efficient ways to passively reduce its energy usage. Glass curtainwalls typically achieve an R-value (measure of a material’s capacity to resist heat flow, with a greater value being more insulative) of approximately R-3, whereas insulated wall systems can achieve R-values greater than R-15. These insulating values are especially important in northern climates where there are more cold days annually and keeping heat from escaping the building envelope is critical.

With the continuing evolution of technologies, it is an ideal time for building professionals to consider new opaque materials. Rather than cladding a building completely in glass, materials can be positioned to strategically highlight attractive views. In most dense cities, for instance, buildings have views that look straight into other buildings. Besides the obvious benefit of a reduction in energy use, improved exterior façade performance may even allow for a reconfiguration or elimination of existing perimeter baseboard heating systems, adding useable area to gross square footage.

Present-day products in the market include materials such as unitized and insulated pre-fabricated “superwall” or modular wall systems that can be installed with the ease and efficiency of curtain wall systems. These systems not only increase performance and quality, but can also be more cost-effective to install than traditional cavity walls due to reduced labor costs.

Energy benchmarking allows for transparency when evaluating comparisons of building energy use and asking: are the buildings of today better than those of yesterday? Can we take some advantages of past designs and integrate them with modern technologies for high performing enclosures? As repositioning/reclad projects become more common, it is important to be aware of present-day challenges and to not only address the economics, but the climatic issues as well. This starts with a desire by the owners, developers, and facility managers, and is executed by designers, contractors, and manufacturers. As the industry continues to pioneer energy efficient façades, stakeholders will need to push the envelope further.

 

Several Foam Insulations Used in Mountain Retreat

Tue, 2019-02-26 16:19
Building ScienceEnergy Efficiency

This home is new, small, efficient, custom-designed and comfortable for a family of four with a cat and a big dog. The sheltering roof pitch is 12/12 and the exterior is rough-cut, vertical barn-boards.  Also chosen for the exterior as part of the inspired Scandinavian design is a metal standing-seam roof. 

In the open and informal interior, most of the windows are operable and are fairly large, creating a strong connection to the outdoors.  The walls and ceilings are white and the floors are Vermont ash sapwood. Though the countertops are topped with laminate for simplicity and durability, the 1-in. birch plywood substrate is exposed on the edges, giving a richer, custom feel.  Custom steel brackets support the open shelving which is combined with flush full-overlay MDF cabinetry with minimal finger pulls.

The location of the Morso wood stove heats multiple spaces and is the primary source of heat all year around.  A smaller sized stove was chosen to be sure the house does not overheat.  Efficiency Vermont was consulted on the details of the HVAC systems, equipment and building envelope.

“They (homeowners, architect, builder and consultant) elected to insulate the 2×6 stick-frame exterior wall cavities with 3 1/2 in. of closed-cell foam and wrap the outside of the exterior walls with 2-in. polyisocyanurate (polyiso) rigid insulation beneath a rain-screen system. They also installed 2 in. of Thermax polyiso rigid insulation of the inside of the full basement walls and 3 in. of extruded polystyrene (XPS) rigid insulation under the slab. (The unfinished basement is used for utilities, storage and their son’s drum set.) Upstairs, the unvented cathedral ceiling is insulated with 2 in. of polyiso on the underside of the 2×12 rafters and dense pack cellulose in the rafter bays.”

Buffalo, NY Residents Fighting Ban on EIFS

Tue, 2019-02-26 13:05

Many buildings in Buffalo are covered with what looks like stucco, but it is usually called Dryvit. Dryvit is part of a product line called Exterior Insulation and Finish System, more often called EIFS. Use of the material is now banned in much of the city under the Green Code, but there is a fight to lift that ban.

Councilmember Richard Fontana wants the ban lifted and there are opponents, calling for expanding the ban. Fontana said it is often a question of how well installation is done.

"Doing it at cut rate cost, they might be putting it on a little bit thinner, not as strong of a material," Fontana said. "So maybe we could have a specification within the code that would be more in the lines of Mr. Paul Brown's quality as opposed to the quality of the lowest bidder, working on a plaza."

Paul Brown is business manager for Plasterers Local 9 and president of the Buffalo Building Trades Council. Brown also is pushing to have the Green Code rules dropped, opening up use of the system city-wide.

If EIFS is installed badly, it will not hold up. That was the point activist Daniel Sack took to the Council, along with photographs of a bad EIFS installation at a local store. Sack said it is not that the installation looks bad.

"What happens is, is when there are holes in the product like that, it gets behind it and there typically isn't a way for that moisture to escape and it causes rot and it causes mold," Sack said. "Mold can be a safety issue, a health issue."

Brown said his apprentices and journeymen know how to install the material properly so it will last. He blasted Councilmembers for trying to expand the ban, saying City Hall pushed the union to hire and train minority residents of Buffalo to do this work. Not allowing it, he said, would be unfair to those workers and to several minority contractors who have started up to install EIFS.

"You guys have encouraged us, urged us, actually badgered us to put people in our apprentice program," Brown said. "We have done that and now you're trying to take the work away from us by taking away the EIFS. If there are certain areas that they don't want to have it, I could care less. Elmwood Village? I don't care. But in general, especially in the industrial areas, they need to have that."

The president of the Buffalo Building Trades Council said opponents of the material seem to prefer metal paneling, but he said that is far more prone to leak. The issue was tabled in the Council's Legislation Committee.

Owens Corning Insulation Segment Up 11% in 2018

Tue, 2019-02-26 13:01

Toledo-based Owens Corning reported a strong 2018 financial performance on Wednesday, with record revenues of $7.06 billion, profits that were up 88 percent, and double-digit increases in adjusted earnings in each of its three building product segments.

OC, which makes insulation, roofing shingles, and composite building materials, said profits last year totaled $545 million, or $4.89 a share. That compared to 2017 profits of $289 million, or $2.55 a share.

Wall Street analysts were expecting $4.79 a share, according to Zacks Investment Research.

The company’s record revenue of $7.06 billion was up nearly 11 percent from revenues of $6.38 billion in 2017.

Owens Corning was aided by stronger pricing of its products and the integration of its acquisition of the Paroc Group, which is a leading producer in Europe of fire-resistant mineral wool insulation, known as "stonewool." In 2017 Paroc had estimated sales of $476 million.

For the fourth quarter, OC’s profits were $171 million, or $1.55 a share, up from a loss of $4 million, or 4 cents a share, in the same quarter in 2017. Quarterly revenues were $1.72 billion, up 7 percent from $1.61 billion from a year earlier.

OC Chairman and CEO Mike Thaman, who plans to relinquish the latter role on April 18, said during a conference call Wednesday with analysts that 2018 marked the first time that all three of Owens Corning’s business segments produced double-digit margins in adjusted earnings before interest and taxes.

Composites increased 12 percent to $251 million adjusted earnings, insulation 11 percent to $290 million, and roofing 17 percent to $434 million.

“This is the first time in Owens Corning's history that we've had this margin performance across the entire portfolio and all three businesses generated (earnings before interest, taxes, depreciation, and amortization) margins close to 20 percent,” Mr. Thaman said.

In net sales, composites decreased 1 percent to $2.04 billion, insulation rose 36 percent to $2.72 billion, and roofing was down 2 percent to $2.49 billion.

Composites sales were hurt by conversions of foreign currency to meet U.S. accounting standards, and slightly lower sales volumes in OC’s core markets, which OC partially offset through higher manufacturing productivity and lower operating expenses, the CEO said.

Insulation sales were boosted by the Paroc acquisition and by a $128 million gain in price improvements in OC’s residential insulation business in North America.

Roofing’s 2 percent drop in sales was due to a reduction in the U.S. market for asphalt shingles, which declined by 5 percent. Growth in the remodeling and new construction markets were offset by lower demand for repairs due to storm damage.

Mr. Thaman, who will pass off the CEO duties in two months to current Chief Operating Officer Brian Chambers, said as he thinks about the past decade, he feels he has built a resilient company. Owens Corning has been among the Fortune 500 list of top companies since the list was created in 1955 and ranked 442nd in 2018.

“We’ve accomplished this through sustainable productivity improvements, organic investment, and acquisitions. Today we have a more diversified portfolio that’s better able to generate strong cash flow, deliver consistent performance, and generally deliver attractive returns for our investors across the cycle,” he said.

“It’s been my honor to represent this company to our investors. Our markets can be challenging and very competitive. But our businesses are market-leading. And I’ve enjoyed the opportunity to share my passion for Owens Corning with you and to have enjoyed your support over the past decade,” he added.

Wednesday on the New York Stock Exchange, Owens Corning stock fell $2.83 and closed at $52.61 a share.

Why Spray Foam in Metal Wall Assemblies is on the Rise

Tue, 2019-02-26 12:57

There is little doubt that the use of foam plastic insulation in metal building exterior roof and wall assemblies is on the rise. 

Over the last few years, I’ve been asked many questions about the use of spray and board foam plastic insulation in metal buildings.  There is little doubt that the use of foam plastic insulation in metal building exterior roof and wall assemblies is on the rise.  This has been driven by several factors, including:

  • Increased minimum performance thresholds in the newer building energy efficiency codes
  • Decreased rated capacity of fiberglass systems in the newer building energy efficiency codes
  • Lower cost of foam plastic insulation created by increasing competition
  • Increased popularity and affordability of spray foam systems

However, simply substituting R-value-for-R-value of insulation systems cannot be done.  Many complications to the metal building envelope design are introduced when foam plastic insulation is used.  Examples of these include:

  • Special fire protection requirements
  • Implications to structural design of secondary framing
  • Installation challenges, particularly with through-fastened roofs
  • Difficulty in evaluating in-place performance levels (i.e., U-factor determination)
  • Thermal expansion and contraction concerns (particularly with spray-foam)

This is just to name a few.  The first point is of primary consideration and will be the subject of the remainder of this blog. Structural issues will be addressed in a future entry.  But before we get into this, it’s important to remember that occupant safety is the absolute highest priority consideration in building design.  While thermal performance is important, nothing can compromise occupant safety and fire protection sits atop the list with structural capacity as a close second.

Spray Foam Provides Cost-Effective Insulation Solution

Tue, 2019-02-26 12:48

Prentiss Balance Wickline Architects was called in to design a retreat home for its clients’ property in Methow Valley, Wash. A modest wish list and a restricted budget resulted in a 1100-sq.-ft. modern ranch-style house with an attached one-car garage. Though sustainable-design features and systems can be expensive, it was important to the clients that they be included where possible. The team identified areas that would offer short- and long-term cost savings. They made the cabin’s footprint as small as would be comfortable, and they used in-floor radiant heating. A combination of blown-in and spray-foam insulation at the roof and walls helped to achieve a supertight building envelope, and passive-solar design strategies included heated concrete floors and deep overhangs, which minimize the need to condition the interior spaces. Indulgences were chosen for their strength of impact. The modest-size great room enjoys the luxury of a double-sided fireplace clad in steel panels and a proportionally large amount of glazing. The 785-sq.-ft. deck was justified because the clients were equally interested in outdoor spaces and knew it would get good use.

The Benefits of Spray Foaming Roof Rafters

Tue, 2019-02-26 12:43
Ask the Carpenter: Where you should insulate may surprise you

Q. I have an attic that was just remediated for vermiculite insulation. It is wide open. A company said I should insulate the roof rafters instead of the joists (the floor) and board up the ridge and gable vents. I have never heard of this. I have a new air-conditioning unit, so maybe it won’t be as hot in the summer this way (heat rises), but heating the attic doesn’t sound very economical in the long run. Please advise.

BILL G.

A. I just did this same thing on a project; I used spray foam insulation on the rafters and left the floor uninsulated. There are several benefits to doing this.

Adding insulation to the rafters and gable walls will hinder the transfer of heat between the living quarters of your home and the attic.

In the winter, heat rises and passes into the attic through the ceiling by conduction or radiation, or through direct air leaks. If your attic is not insulated at the rafters, that heat is lost and ice dams could form. Lost heat also causes your furnace to run longer.

In summer, a hot attic will radiate heat into the rooms below, making your air-conditioning run longer or cycle more often, causing more wear and tear on the unit.

Spray-foam insulation overhead in the rafters creates a conditioned attic space, while insulation in the floor system creates an unconditioned attic area.

If you have an HVAC unit or ductwork in the attic, then those are exposed to both temperature extremes. In the summer, hot ductwork takes away cool air inside the piping. In the winter, cold ductwork takes away from the warm air inside, and you run the risk of frozen pipes.

You won’t be wasting heat by not insulating the floor. If you are still concerned, use spray-foam insulation on the rafters and Fiberglas insulation on the floor to separate your home and attic heating zones.

 

Q. My husband and I incorporated a pantry and an enclosed back porch into a kitchen gut renovation many years ago, putting on a 4-by-4-foot addition and squaring off the back porch to the house. There’s no foundation under the addition. It abuts our home’s foundation on one side and the bulkhead’s foundation on another. The other sides are open with a concrete support post between them. The floor that overhangs this space gets really cold in the winter, so we thought it would help to “enclose’’ the addition. Our thoughts to accomplish this:

  • Lay heavy mil plastic on the ground as a moisture barrier and put concrete pavers on top to keep it in place (not sure the pavers are really needed);
  • Dig a small trench on the two open sides and lay concrete blocks from the ground up to the floor of the addition (cementing between layers and between blocks — probably three layers worth of blocks – like a foundation but not built down into the ground);
  • Fill the area with Fiberglas batting or some other more appropriate insulating material;
  • Seal the exterior blocks with a skimcoat of concrete.

The house was built in 1907 and has a fieldstone basement. That stone is exposed above grade with a skimcoat of concrete.

What do you think we should do?

KAREN KITA

A. Your approach would fail over time. I would open the floor cavity from below, add spray-foam insulation, close it up with ½-inch pressure-treated plywood, and call it a day. You can also apply spray foam to the rim joist in the basement to prevent air leaks around the fieldstone and house sill.

I would also look for ways to bump up the heat in your kitchen. Area rugs also help.

Rob Robillard is a general contractor, carpenter, editor of AConcordCarpenter.com, and principal of a carpentry and renovation business.

Chart: OSB Prices Continue to Decline in January 2019

Wed, 2019-02-20 17:03
Raw Materials

For the third consecutive month, OSB prices (NSA) declined the most in percentage terms (-6.1%).  Prices paid for OSB have decreased nearly 30% since October 2018 and have fallen more than 40% since hitting their most recent peak in June 2018. The post-peak price trends of OSB and softwood lumber are shown below.

Video: Improve Residential Walls with Continuous Insulation

Wed, 2019-02-20 16:59
Building CodesBuilding ScienceEnergy Efficiency

Continuous Insulation (CI) is now defined in the IBC as follows: "Insulating material that is continuous across all structural members without thermal bridges other than fasteners and service openings. It is installed on the interior or exterior, or is integral to any opaque surface of the building envelope."

Today CI is virtually required in commercial construction.  But residential walls, typically framed with wood, not steel, have less of an issue with thermal bridging.  So is the use of CI on these types of structures worth it?  Absolutely!  CI will  improve any wall, particulary if the goal is to have the perfect energy efficient wall.

While you might not need to replace all of the cavity insulation of a wood-framed wall with continuous insulation, even just a thin layer makes a big difference.  By enclosing the framing members in insulation, you are keeping them from larger temperature fluctuations that can promote condensation and the adverse effects that take place when wood is wet for long periods of time.  Also, continuous insulation can often be used as an all-in-one WRB, air barrier and vapor retarder, simplifying construction.  To learn about these applications and more, visit continuousinsulation.org for research reports, step-by-step guides, articles, and helpful tools like the wood wall calculator.

As an introduction, here’s a short video explaining the basics of wood-framed wall design:

For additional information, please review the following articles, as well as the previous videos in this series:

Perfect Wall Articles

  1. Polyiso CI Helps Designers Achieve a 'Perfect Wall'
  2. New Wall Design Calculator for Commercial Energy Code Compliance
  3. Energy Code Math Lesson: Why an R-25 Wall is Not Equal to a R-20+5ci
  4. Continuous Insulation Solves Energy Code Math Problem
  5. Perfect Walls are Perfect, and Hybrid Walls Perfectly Good
  6. Wood Framed Wall Insulation Calculator Explained

Video Series

  1. Fear Building Envelopes No More with This Website & Videos
  2. Thermodynamics Simplified Heat Flows from Warm to Cold
  3. Moisture Flow Drives Water Induced Problems
  4. Video: How the 'Perfect Wall' Solves Environmental Diversity
  5. Video: How Important Is Your WRB?
  6. Video: A Reliably Perfect Wall Anywhere
  7. Video: The Best Wall We Know How to Make 
  8. Video: How to Insulate with Steel Studs
  9. Video: Thermal Bridging and Steel Studs

Guide for Choosing the Right Caulks & Sealants

Wed, 2019-02-20 16:49
Building Science

Editor's Note: The follow article was written by Mark Platz, industrial business manager, ITW Polymer Sealants North America, Irving, Texas

Caulks and sealants are used in metal construction to fill gaps and cracks. They are a barrier to prevent the passage of air, water, moisture, gas, noise, dust and smoke. Generally representing less than 1 percent of a building's cost, they are extremely important to the water/airtightness of the building. For this reason, correct selection based on properties and applications is important to the weathertightness of the building envelope.

Caulks

Caulks typically are associated with filling gaps that do not experience much expansion or contraction, and are used to prepare for painting. They are rigid and inflexible. In metal construction, caulks are used on the interior filling gaps between drywall, windows and trim, or casework before paint is applied.

"The word caulk is an old boat building term and is sometimes used by manufacturers as a general purpose term for acrylic materials with little or no movement capability," says Jason Bakus, vice president of Sealex Inc., Harbor Springs, Mich. "Acrylic latex caulks are normally paintable with water-based or solvent-based paints, but are not generally used in metal construction due to the amount of shrinkage they experience as well as their tendency to crack over time. Most manufacturers refer to their elastomeric sealing products as sealants."

Tale of the Tape

Butyl tapes are most commonly used to seal the side- and end-laps of standard single-skin panels. Butyl tape is a non-curing, 100-percent -solids compound that is a highly rubbery, tacky sealant which remains permanently flexible. Butyl tapes are packaged in rolls or strips with a removable release liner for easy handling and application. Butyl tapes are soft and pliable and are designed to compress between overlapping panels to form a positive seal. With elongation values greater than 1,000 percent, butyl tapes can last for 25-plus years and are compatible with all painted metals including but not limited to Galvalume-, Zincalume- and Kynar-coated products. With application temperatures between -5 F to 120 F and service temperatures from -40 F to 200 F, they are routinely used in all climates. Although butyl tapes exhibit excellent UV characteristics, proper application would not require them to be exposed to direct sunlight. Also, antimicrobial additives are used by some manufacturers to inhibit the growth of molds and mildew.

Sealants

Sealants play a vital role in metal construction and act as a seal between metal and other exterior materials to form a barrier for infiltration or exfiltration of moisture, air and airborne particles.

"Sealants are used when there is a high likelihood of expansion, contraction or movement between the metal substrates and are designed with polymers allowing flexibility," says Dr. Roger Moore, director of marketing and product support manager, Novagard Solutions Inc., Cleveland. "Sealants like Novaflex metal roof sealant serve in a number of roles in metal construction including structural glazing as well as any application where a seam between two metal substrates come together and a flexible watertight seal is required."

Sealants are used in many different applications in metal construction ranging from standing seams, metal end laps, roof penetrations and curbs to expansion joints, roof to wall transitions, roof steps and height changes, ridge expansions, gutter seams and many others.

Metal panels create a couple of distinct challenges for sealants. "First, metals expand and contract with changes in temperature, so joints with metal panels definitely experience dynamic movement," says Bee Miller, manager of market development, Architectural Specifications, Franklin International- Titebond Adhesives and Sealants, Columbus, Ohio. "Additionally, because many of the most common paints and surface coatings in the industry are designed to last for a long time, some of the specialty coatings can be challenging to bond to and maintain a strong bond with."

Silicone

Silicone sealants provide excellent joint movement capabilities (ASTM C920, Classes 25, 35, 50 and 100/50) up to 50 percent. Silicone sealants offer superior adhesion to common building material substrates including glass, aluminum, wood, steel, vinyl and masonry. However, a primer is recommended for use on some substrates, particularly cementious substrates. "Documented studies on the long-term performance of silicone sealants have been published by the major manufacturers and indicate performance in excess of 20 years in terms of resistance to moisture, oxidation, high temperatures and UV exposure," says Moore. "These products are not recommended in high-traffic areas where abrasion may cause degradation of the surface. Application temperatures of silicone sealants far exceed those of inferior polymeric sealants and often range as low as -20 F to +140 F and also have large service temperature ranges such as -40 F to +400 F."

Most silicone formulations are not paintable; however, modified silicone sealants may be paintable. Silicone sealants may stain some porous substrates such as concrete and some natural stone substrates. Silicone sealants are well known for their ease of application and clean up. They are typically 100 percent solids, or non-solvent type, and easily meet VOC environmental regulations, are not flammable and clean up easily after use.

Pre-cured silicone sealants-or silicone membranes as they are sometimes called-are commonly used in a variety of metal building applications. "Because of their ultra-high movement capability (200 percent plus) and unique properties, they are used for sealing high movement areas on metal building applications such as expansion joints, roof to wall transitions, roof height change details, joints between new and existing buildings, ridge applications and others, including a variety of repair applications," Bakus says. "Pre-cured sealants are bonded to metal and other substrates using a separate adhesive and require no fasteners."

In the past, there has been some concern with compatibility of some silicone sealants with metals such as Galvalume and galvanized. "This issue was with acetoxy (acid-based) cure products, which are no longer used in metal construction applications," Bakus says. "Neutral cure silicone sealants have been used in metal construction applications for many years and do not pose corrosion problems with these metals."

Polyurethane

Not used as commonly as silicones, polyurethane sealants offer superior joint movement capabilities and have good adhesion to most common building substrates. Polyurethanes for the metal building industry are generally one-component, moisture-cure sealants designed to skin and cure rapidly. Premium polyurethanes are specified due to their superior UV resistance and long term durability.

Builders should select a polyurethane with a minimum of 50 percent joint movement: +/- 25 percent. "Selection of polyurethane can depend on substrate," says Mark Platz, industrial business manager, ITW Polymer Sealants North America, Irving, Texas. "With today's specialized coatings, not all polyurethanes adhere the same to all surfaces. While some can adhere to wet surfaces or even underwater, others may require a primer or pretreatment depending on the substrate. Premium polyurethanes remain flexible with life expectancies reaching 20-plus years depending on exposure to extreme elements. They cure to a tough, durable, elastic consistency with excellent cut-and-tear resistance, come in a variety of colors, and most are paintable.

"With service temperatures from -40 F to 200 F and elongation availabilities of 500 to 600 percent polyurethanes are frequently requested by the metal building contractor. Polyurethanes are available in gun grade (cartridges) and can be non-sag or self-leveling. They are easy to tool for an aesthetically clean finish. When applied in close proximity, neutral cure silicones can prevent polyurethanes from curing. This problem does not exist if either product is allowed to cure prior to application of the other."

Typically polyurethanes exhibit good compatibility with the metal and masonry surfaces; however, "They should not be used in structural glazing applications with contact with glass," cautions Moore. "These sealants can be formulated to give aboveaverage UV resistance and may be paintable. Some formulations contain solvent, and shrinkage due to solvent evaporation must be taken into consideration." Some health professionals recommend wearing respirators during application.

Solvent based

The most common solvent-based synthetic rubber sealants are acrylic. They are most often used in perimeter sealing or other low joint movement applications. They may need special handing due to flammability and they have environmental considerations. "Solvent-based sealants typically have good durability and can be applied at below freezing temperatures," says Miller. "They are typically paintable but only after a seven- to 14-day full-cure period. They are flammable in the wet state, can be difficult to tool due to short open times, and can produce a significant odor during application and cure time."

Butyl sealants

Non-skinning, non-drying (Butyl) sealants are the primary sealant in standing seam roofs and the joints of insulated metal panels. Designed to stay soft and flexible, they ensure a positive seal when jointing roof or wall panels. They should exhibit a non-stringy consistency with easy cut-off characteristics for clean application.

"Butyl sealants are easily pumped into the female leg of standing seam roof panels and are compatible with all current types of paints and coatings used by today's rollformers," says Platz. "This product does not cure like standard pumpable sealants, allowing for movement, self-healing, and can offer a life expectancy equal to that of the roof system. This sealant requires an application temperature range of 10 F to 120 F and a service temperature range of -60 F to 200 F. This is a non-curing sealant, therefore it is not paintable, is supplied in white or off-white (color) and is used in conjunction with mechanical fasteners."

The hybrids

Within the past few years, hybrid sealants such as modified silicone (MS) (silyated polyether) and SPUR (silyated polyurethane) have come onto the construction market and claim the best qualities of both silicone (UV resistance) and polyurethane (paintability). Hybrid sealant use in metal construction is minimal at this time, but is growing.

"Common hybrids used are tested to withstand +/-50 percent expansion/contraction," says Miller. "Hybrid life expectancy is generally very good. Appearance and UV resistance are very good, and they are typically paintable if discoloring occurs from weathering over time. They handle and tool nicely and have low to no odor."

Evaluation

When selecting caulks and sealants, evaluate all performance characteristics to determine the optimum sealant against the cost. Discuss your sealant applications with the manufacturer to determine the best product for each application as there is no one product for all applications. Compatibility with the substrate may require different curing mechanisms.

 

 

Demilec’s Heatlok Spray Foam Up for ‘Best Green Product’

Wed, 2019-02-20 16:43
Building ScienceEnergy Efficiency

Demilec® Inc. announces Heatlok HFO has been nominated for the National Association of Home Builders’ 2019 Best of IBS Award in the Best Green Building Product category. It will compete against several other environmentally conscious products in the building materials industry.

The winner will be announced on Thursday, February 21, 2019 at the International Builders’ Show (IBS) in Last Vegas. Each year IBS, hosted by the National Association of Home Builders (NAHB), boasts an attendance of more than 70,000.

Demilec’s Heatlok HFO family of products uses a blowing agent with ultra-low global warming potential and Zero Ozone Depleting potential. Heatlok HFO High Lift and Heatlok HFO Pro recently won the coveted 2018 CPI Innovation Award and 2018 Home Builder Executive Gold Innovation award for their high R-values of 7.5/inch and 7.4/inch, respectively. Heatlok HFO High Lift can be sprayed at 6.5” for an R-49 in a single pass. While Heatlok HFO Pro is a certified ABAA air barrier, ideal of continuous insulation sprayed on the home’s exterior.   

Aside from thermal efficiency, both products feature other environmental benefits. Heatlok HFO products are composted of 12.5% post-consumer waste. To date, Demilec has been responsible for recycling more than 400 million plastic bottles for manufacturing. Heatlok HFO creates no job site waste and is sprayed from reusable bottles.

Demilec recently announced that both products are radon gas resistant and can be used in place of a conventional plastic membrane around the exposed foundation of a new or restoration building project. It is also 11 times more thermally efficient than the conventional membrane.

“Demilec is excited Heatlok HFO Insulating Spray Foam has been nominated for the Best Green Building Product by NAHB. Demilec’s dedication to sustainability and utilization of recycled PET in our foam has been a core focus of our product development,” according to Douglas Brady, VP of Product Management and Technology at Demilec. “Now, combined with a 4th generation HFO blowing agent, we have significantly reduced the greenhouse gas impact of spray foam while continuing to protect the ozone.”

Kingspan CI Creates Home with HERS Rating of Zero

Wed, 2019-02-20 16:40
Building ScienceEnergy Efficiency

Kingspan Insulation is focused on bringing innovative building performance solutions in energy efficiency and moisture management products to builders, contractors and architects. By improving the building envelope, energy loss can be reduced and Kingspan has expanded its insulation product lines over the past 2 years to continue to offer the market a wide variety of solutions for wood frame, steel frame, residential and commercial construction.

This year, Kingspan sponsored NAHB's The New American Remodel™ 2019 as well as the KB Home ProjeKt. Both homes incorporated Kingspan Kooltherm premium performance insulation boards, in a continuous insulation and friction-fit applications respectively, allowing for increased energy efficiencies with the KB Home ProjeKt at a RESNET HERS rating of zero.

"We wanted to partner with the show home builders to create case studies on sustainable building practices, building performance and health & wellness," said Suzanne Diaz, Marketing Manager for Kingspan Insulation North America. "There is an increased focus on smart homes as well as net zero building practices, and The New American Remodel and KB Home ProjeKt houses truly showcase what the future of remodeling and new-build construction practices could look like."

The Kingspan Kooltherm® line offers an extensive range of products for wall, floor, soffit, rainscreen, concrete sandwich wall system (precast and tilt-up) applications. It has a fiber-free rigid thermoset phenolic insulation core, and exhibits outstanding fire performance. With an R-value of 16 on two inches, Kooltherm® has a higher R-value than any commonly used insulation. It is manufactured with a blowing agent that has zero Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP). The product is light weight, easy to install, and is unaffected by air infiltration and is resistant to the passage of water vapor. It is ideal for new construction as well as retrofit.

The New American Remodel™ also used GreenGuard® RainDrop® 3D Building Wrap, Butyl Flashing and Seam Tape for a complete moisture management wall system. GreenGuard® RainDrop® 3D Building Wrap provides both an air & moisture barrier with an integrated drainage plane, and can be used with siding, stone or stucco.