SMART Choices for T24 High Performance Attics

Transcription

1 SMART Choices for T24 High Performance Attics Achieving High Performance with Smart Vapor Retarders 1 / WISE 2017 Forums for High Performance Installation

2 WHAT ARE SMART VAPOR RETARDERS?

3 The Problem Vapor retarders and barriers (<1 perm, whatever the RH) are efficient in winter to prevent any moisture flow to the wooden structure But they also prevent any drying to the inside in summer: Condensation Presentation 3 / title

4 leads to a SMART Solution. A Smart Vapor Retarder (SVR) has a variable vapor permeability with moisture, and is airtight RH inside a house in winter ~40%RH Moisture coming from outside in summer Presentation 4 / title

5 CertainTeed MemBrain or SmartBatt Vapor close membrane (ex. Bitumen paper) or airtight Smart Vapor retarder Drying to the inside (Summer)

6 High Performance Attics There are more options than you think High Performance Attics: Option A High Performance Attics: Option B High Performance Attics: Option C High Performance Attics: Option C Insulation Installed Above Roof Deck Wires, Plates or Supports SMARTBATT Stapled in Place Ducts in the Conditioned Space Sub-Option 1: HVAC in the Conditioned Space (via dropped ceiling or modified truss design) Sub-Option 2: ocspf or ccspf Ducts in the Conditioned Space Sub-Option 3: Boxed Netting or Batts 6 / Presentation title

7 CA Title 24 Option A CertainTeed Roofing FlintBoard Iso NB Polyiso board with pre-glued OSB (7/16 or 5/8 ); fiber reinforced felt at the bottom. Available in R6.3 (1.1 ) or R8 (1.4 ) - aged R-values 7 /

8 HIGH PERFORMANCE ATTICS: OPTION B

9 9 / Presentation title CA Title 24 Code Option B

10 Existing Options B: Wires or Plates Metallic wires, plates or rope: possible but time consuming Insulation support: bends the insulation (reduces the R-value) 10 /

11 CertainTeed Option B SMARTBATT R13 (Fire Class A), stapled between rafters SMARTBATT has a smart vapor retarder facing no moisture accumulation. Moisture driven from the outside to the inside in summer diffuses to the ventilated space. 11 /

12 WHAT MAKES IT SMARTER? CERTAINTEED SMARTBATT UNFACED & WIRE Easily passes QII High quality look Will not sag or fall down Less Thermal Bridging Issues Actively manages moisture Easy & simple to install Less Dust Difficulty to pass QII Poor quality look Can sag and fall down More thermal bridging Issues Doesn t actively manage moisture Multi-step install Dustier Install 12

13 13 / HIGH PERFORMANCE ATTICS: PERFORMANCE OPTIONS

14 CA Title 24 Code Option C Ducts in the conditioned space 14 / 14 /

15 CA Title 24 Code Option C Sub-option 1: Dropped ceiling or modify truss design to place the HVAC in the conditioned space Advantage: keep on using blown insulation on the attic floor and vented attics (no change in habits) Drawback: change the design of all the trusses, loss of sf in the house (air handler in a closet), limits the options for HVAC drops positions (risk of comfort issue) 15 / 15 /

16 CertainTeed CertaSpray X and CertaSpray closed cell Sub-option 2: open cell or closed cell SPF CertaSpray X (CSX) Open Cell Spray Foam Insulation meets the requirements of AC377 Appendix X and can be installed in attics without the need for an ignition barrier or additional intumescent coating. 16 /

17 Blown insulation or unfaced batts Sub-option 3: blown insulation of unfaced batts under the roof deck Challenges: - Airseal the roof deck safety concern with high pitch - Install a diffusion port (roofers) - Condition the attic space (HVAC return in the attic space) Main risk of moisture accumulation at ridge ( night overcooling effect) Pictures: Building Science Corporation 17 /

18 The Smart Choice for HPAs Step 1: Install Hangers/Rails Step 2: Install SMARTBATT Step 3: Install Tape 18 / WISE 2017 Forums for High Performance Installation

19 CertainTeed Solution SMARTBATT for insulation, moisture management and airtightness Raise insulation level above the HVAC and keep ventilation at the ridge Safer installation (can be stopped at 4 or 5ft high), easier for roof repairs QII compliant: insulation in contact with the air barrier (= facing inside) 24.5 wide batts between trusses to avoid any thermal bridge Ventilated ridge Roof surface: 160F Building envelope (airtight) 70F/50%RH HVAC ducts No condensation Real Option C: Ducts in conditioned space Continuity of airtightness layer 19 /

20 Installation Possibility to stop the insulation at 4-5ft (safe, productivity), go horizontally Lower volume of partly conditioned space (better energy efficiency) 5ft 24.5 wide batts: fill the gaps, no thermal bridge 20 / Hanger lips can be snapped to go around complex details

21 Final Installation CertainTeed solution: R30/38 insulation + fire class A + Smart Vapor Retarder + airtightness 21 / SmartBatt facing = air barrier, QII compliant SmartBatts + tape: ACH50 measured at 1.6 in a real house (Home Innovation Labs, 3 rd party), no problem for future CA code to reach ACH50<3

22 How do you spell SMART? Performance Versatility Durability Quality Simplicity Attic Performance Air tightness and moisture management at facing; identify & repair air leakage easy Keep roof ventilation: lower temperatures and less chance for condensation at ducts Ability to create envelope at any height in attic Reduce safety concerns Reduce conditioned space for homeowner Less materials Durability Clips and rails hold material in place not staples Tested to over 200F for expansion and contraction Designed to meet seismic requirements Aesthetics Beautiful look; Customers- just looks nice, very high quality QII Taping and stapling of facing meets six side requirements Easy to order kits One SKU per 1000 sq. ft 22

23 23 / SMARTBATT BEHIND SHOWER ENCLOSURES

24 Housewraps in bathrooms Vapor permeable housewraps are used behind bathtubs in CA to comply with QII C11 and C12: the insulation must have a 6-side contact with an air barrier. They are installed by framers, not insulation contractors (logistic issue on job sites). These products have a high vapor permeability, which can lead to potential issues in winter (high RH in the bathroom and moisture flow to outside). Presentation / / title

25 Solution: SmartBatt + CertaTape CertainTeed SmartBatt (SVR) can be installed by insulation contractors and performs better than housewraps in CZ 1 and 13 Tyvek SmartBatt VR 0.1 perm 25 / 1. Arcata fail pass 2. Santa Rosa pass pass 3. San Francisco pass pass 4. San Jose pass pass 5. Santa Maria pass pass 6. Los Angeles pass pass 7. San Diego pass pass 8. Fullerton pass pass 9. Burbank pass pass 10. Riverside pass pass 11. Red Bluff pass pass 12. Sacramento pass pass 13. Fresno fail pass 14. Palmdale pass pass 15. Palm Springs pass pass 16. Blue Canyon pass pass Fail means here high moisture content and high probability of mold growth on the external sheathing with R15 between studs.

26 Solution: SmartBatt + CertaTape CertainTeed SmartBatt (SVR) Performs better than unfaced and housewrap - Airtight with tape - Manages moisture Product stays in cavity (does not fall out) - No call backs Can be installed by insulation contractors - Productivity Product stays with six sides of contact (no settling) - QII- No deductions 26 /

27 THANK YOU Ted Winslow Brand Product Manager Bldg. Sci., Systems & Tech. Mktg. (610) / WISE 2017 Forums for High Performance Installation