Meeting the Challenges of Emerging Air-Tightness Requirements

Transcription

1 Meeting the Challenges of Emerging Air-Tightness Requirements Best Practices that Add Up Copyright 2016 Owens Corning. All Rights Reserved. The color PINK is a registered trademark of Owens Corning. James Rinne Senior Engineer Owens Corning 28 September 2016 Dallas, Texas

2 Air-tightness standards are increasing Climate Zones Requirement ACH ACH50 2

3 Why is 3ACH a heavy lift? I. Knowledge What s Leaking? II. Building process It s complicated! III. Change It s difficult! (But possible) 3ACH 3ACH

4 If you re looking for silver bullets

5 KNOWLEDGE What s leaking? How do I seal it?

6 Categories of air-leakage 1 blocking issues 2 penetrations 3 joints Image Credit: U.S. Department of Energy

7 Blocking issue blocking issue n a large hole in the air-barrier created by the absence of a matching piece of air-impermeable material like wood.

8 Blocking issues > knee wall *Section Excerpted from the 2009 International Energy Conservation Code, Copyright Washington, D.C.: International Code Council. Reproduced with permission. All rights reserved. Root cause: complex framing awareness gaps at top plate no blocking between joists blocking between joists Image courtesy of Southface Energy Institute

9 Blocking issues > porch roof unsheathed wall section Root causes: sequencing restricted access division of labor complex framing awareness unsheathed wall section

10 Blocking issues > uncapped cavities Root causes: complex framing awareness no top plate blocking no top plate blocking

11 Blocking issues > cantilevers & bump-outs Root causes: sequence visibility human error cantilever box window

12 Penetrations Penetration n a hole created in the airbarrier, usually for the purpose of adding functionality to a house.

13 Penetrations examples pipe-sheathing can-drywall boot-drywall flue-collar

14 Penetrations smurf tube sealed smurf tube? not inside.

15 Joints (but lots of length) Joint n a small hole in the air-barrier created at the interface between two adjacent building materials, like drywall and wood.

16 Joint air leakage study

17 Tightness Joints high leakage ( CFM50/ft) Duct boots Top plate-to-attic Recessed lights Most effective Sealing cost Band joist (top & bot.) Garage-to-house common wall Dave Wolf, Characterization of Air Leakage in Residential Structures, EEBA 2012

18 Tightness Joints medium leakage ( CFM50/ft) Moderately effective Corners Sealing cost Sheathingto-plate (top & bot.) Window/Door Framingto-Sheathing Dave Wolf, Characterization of Air Leakage in Residential Structures, EEBA 2012

19 Tightness Joints low leakage (0 0.2 CFM50/ft) Least effective Between Ext. Top Plates Sealing cost Plate-tosubfloor/slab Vertical Sheathing Seams Dave Wolf, Characterization of Air Leakage in Residential Structures, EEBA 2012

20 What product do I use? joints only lower cost tapes, caulk, gaskets, gun foam fewer joints (framer) more joints (insulator) interior spray foam membranes (wraps, peal & stick, fluid-applied, poly) exterior exposure higher cost complete coverage

21 Other things to consider One sealant does not seal all joints! Joint movement Durability

22 PROCESS It s complicated!

23 Process for creating air-barrier (simplified) framer FRAME inspection VARIABLES weather, supply, demand, absence, cornice SEATH utilities PENETRATE coordination inspection insulator SEAL TEST CONSTRAINTS maximize production, return on investment, minimize cost, labor, schedule, return trips rater

24 Implications for who has air-sealing responsibility Who should seal this? flue-collar Who should seal this? Pros Cons Insulator Fire place installer Consolidate responsibility Seal penetrations when made Insulator has to buy high temperature sealant Distribute responsibility

25 Sequencing issues blocked access to downstream trade blocked access delayed delivery

26 Communication helps work around sequencing issues

27 Lifting constraints to achieve less than 1 ACH50 ceiling drywall before interior walls eliminates top-plate leakage Image courtesy of Steven Baczek, Steven Baczek Architectural Services

28 Change It s possible

29 A case study 2015 Highland Homes started working with Owens Corning on achieving the new 3ACH50 standard. Average ACH50 5 Here s what we did leveraged 2012 air-leakage study implemented cost effective gasket Owens Corning supported transition to a new process

30 Overview of framing gasket approach thicker than sill seal W = 3 window top plate corner L = 50 base plate exterior before sheathing 3 man-hours framing gasket 60 rolls/house top plate interior before drywall 3 man-hours

31 Training Days before first install During install team meeting WHO supervisors, purchasing manager, framing contractor, insulator, drywaller, energy rater WHY educate on proper installation emphasize importance of air-barrier raise awareness of upcoming changes foster communication between trades HOW learn through discussion at job-site English, Spanish, WHO installer, supervisors installer training WHY educate on proper installation assess time to install HOW learn by doing, trial & error at job-site English, Spanish,

32 Instructions Provide to job-site supervisors Show where and how product is applied English and Spanish

33 Focus on supervisors to sustain new process orchestrates building process and interacts closely with installers air-sealing knowledge supers trades building process Building Process

34 Diagnostics reveal opportunities for improvement faulty dampers improve process blower door testing smoke testing make an impression find the leaks

35 Continuous improvement mindset opportunity to improve It even helps when disposal crews are aware of new process

36 Where are they now? 2.5 ACH50

37 Recap There are no silver bullets. full air-leakage study available online Keys to success Education and awareness Continuous improvement mindset Change is possible! 1. D. Wolf, F. Tyler, Characterization of Air- Leakage in Residential Structures Part 1: Joint Leakage. 2. D. Wolf, F. Tyler, Characterization of Air- Leakage in Residential Structures Part2: Whole House Leakage. Thermal Performance of the Exterior Envelopes of Whole Buildings XII International Conference, 2013 ASHREA.

38 Meeting the Challenges of Emerging Air-Tightness Requirements James Rinne, Ph.D. Owens Corning, Science & Technology Questions?