Learning Objectives 9/3/2013

Transcription

1 Air Barrier Testing for Code Compliance Theresa A. Weston, PhD. & Benjamin Meyer DuPont Building Innovations ICC Annual Conference Atlantic City, NJ October 2, 2012 Learning Objectives Understand how does air leakage impacts a building s sustainability Review recent code regulations for air leakage control Understand air leakage test methods for materials, assemblies and whole buildings Present examples of whole building testing from the USACE measurement and verification program for building envelope airtightness SECTION 1: AIR LEAKAGE ACROSS TE BUILDING ENCLOSURE: WAT IT IS AND WY WE CARE 1

2 SECTION 1 2 What is Air Leakage? Unplanned/Unpredictable/Unintentional Airflow P i P P o Air Leakage needs BOT: 1. A Driving Force ( Pressure) 2. A Pathway (Unintended Opening) SECTION 1 2 Transport of: Impact on Buildings SECTION 1 2 Air Leakage Impact on the VAC Energy Use Exfiltration of Conditioned Air P Infiltration of Unconditioned Air *Source: NIST Report Investigation of the impact of Commercial Building Envelope Airtightness on VAC Energy Use, S. J. Emmerich, Tim McDowell, W. Anis 2

3 Effect of Air Leakage on eating and Cooling Energy 6.6% to 16.3% /AC energy reduction results from an 18.6% reduction in air leakage, dependent on climate. E. I. DuPont de Nemours and Company All rights reserved Air Leakage Impact on Energy Use: Degradation of Thermal Insulation Performance Source: Impact of Airflow on the Thermal Performance of Various Residential Wall Systems utilizing a calibrated hot box, Thermal Envelopes VI/ eat Transfer in Walls -- Principles 3

4 SECTION 1 2 Rating of Moisture Sources in Buildings Water Vapor Bulk Water Rain & Snow: (above grade envelope) Transported by air currents Diffusion 1 98% 2% >>1,000X X 1X SECTION 12 Wintertime Condensation Air leakage condensation potential can be estimated by determining the hourly dew point of the interior air, and the temperature of the potential condensation plane:» When the temperature of the condensation plane is below the dew point of the interior air, condensation would occur if air exfiltration reaches the condensation plane. Exterior Temperature Profile Cooler Surfaces Interior Interior, moisture-laden air Exfiltration could lead to condensation on cooler exterior surfaces, e.g. if the temperature of the sheathing is below the dew point of the interior air Air Leakage Condensation Potential: Chicago Example --eating Season, Air Exfiltration 4

5 SECTION 1 2 Summer Time Air Leakage Condensation Potential Exterior Cooler Surfaces Interior Exterior, moisture-laden air Infiltration could lead to condensation on cooler interior surfaces, e.g. if the temperature on the back of interior Vapor Retarder is below the dew point of the exterior air SECTION 1 2 From Preventing Moisture and Mildew Problems in ospitality Industry Buildings -C2M ILL SECTION 1 2 Air Leakage Impact on Energy Use: Moisture Impact on Thermal Insulation Performance * The insulation thickness has only a small effect on the % R-value reduction (measured at 20 degree C temperature difference) Source: Controlling the Transfer of eat, Air & Moisture through the Building Envelope M.C. Swinton, W.C. Brown, G.A. Chown 5

6 SECTION 1 Garage / ouse Interface Air Leakage 1. Based on the airtightness testing completed on an additional 42 homes with attached garages, it was found that, on average, interface leakage accounts for approximately 10 per cent to 13 per cent of the total house leakage area. At these levels of garage-to-house transfer, carbon monoxide (CO) concentrations remainwithin acceptable exposure limits recommended byealth Canada. 2. If more than 25 per cent of the house air leakage occurs through the garage, our simulations show that garage based emissions could cause significant house indoor air quality problems. 3. Three remediation strategies were tested. All three strategies were found to reduce peak concentration of pollutants in both the garages and the houses where they were tested. Air sealing during construction is recommended to avoid pollutant entry. If a garage air infiltration problem is noticed in an existing house, airsealing should be the first line of defense. Source: CMC Research ighlight , April 2004 E. I. DuPont de Nemours and Company All rights reserved SECTION 1 2 What is Air Leakage Unplanned/Unpredictable/Unintentional Airflow P P i P o Air Leakage needs BOT: 1. A Driving Force ( Pressure) 2. A Pathway (Unintended Opening) No pathway: No Flow P i P P o No Air Pressure: No Flow Pathway (Unintended Opening) SECTION 1 Sources of Air Pressure Difference ( P) Wind Pressure Stack Pressure Mechanical Pressure 6

7 SECTION 1 Wind Pressure SECTION 1 Stack Pressure Source: 2009 ASRAE andbook of Fundamentals. SECTION 1 2 Source: Weston, T. A. et. al., Preliminary Investigation of Moisture in Walls of Manufactured omes presented at the Conference on Durability and Disaster Mitigation in Wood-Frame ousing, Madison, E. WI, I. October, DuPont 2001 de Nemours and Company All rights reserved 7

8 SECTION 1 2 What is Air Leakage Unplanned/Unpredictable/Unintentional Airflow P P i P o Air Leakage needs BOT: 1. A Driving Force ( Pressure) 2. A Pathway (Unintended Opening) No pathway: No Flow P i P P o No Air Pressure: No Flow Pathway (Unintended Opening) SECTION 1 2 Air Leakage can occur: Through joints between materials, or Through materials themselves Section 2: Continuous Air Barriers: Code Requirements, Verification and Test Methods 8

9 Definitions AIR BARRIER. Material(s) assembled and joined together to provide a barrier to air leakage through the building envelope. An air barrier may be a single material or a combination of materials. CONTINUOUS AIR BARRIER. A combination of materials and assemblies that restrict or prevent the passage of air through the building thermal envelope. VAPOR PERMEABLE. The property of having a moisture vapor permeance rating of 5 perms (2.9 x kg/pa s m2) or greater, when tested in accordance with the desiccant method using Procedure A of ASTM E 96. A vapor permeable material permits the passage of moisture vapor. VAPOR RETARDER CLASS. A measure of the ability of a material or assembly to limit the amount of moisture that passes through that material or assembly. Vapor retarder class shall be defined using the desiccant method with Procedure A of ASTM E 96 as follows: Class I: 0.1 perm or less Class II: 0.1 < perm 1.0 perm Class III: 1.0 < perm 10 perm WATER-RESISTIVE BARRIER. A material behind an exterior wall covering that is intended to resist liquid water that has penetrated behind the exterior covering from further intruding into the exterior wall assembly. AIR-IMPERMEABLE INSULATION. An insulation having an air permanence equal to or less than 0.02 L/s-m2 at 75 Pa pressure differential tested according to ASTM E 2178 or E Commercial: IECC Air leakage. (Mandatory) Window and door assemblies. The air leakage of window and sliding or swinging door assemblies that are part of the building envelope shall be determined in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, or NFRC 400 by an accredited, independent laboratory, and labeled and certified by the manufacturer and shall not exceed the values in Section Exception: Site-constructed windows and doors that are weatherstripped or sealed in accordance with Section Curtain wall, storefront glazing and commercial entrance doors. Curtain wall, storefront glazing and commercial- glazed swinging entrance doors and revolving doors shall be tested for air leakage at 1.57 pounds per square foot (psf) (75 Pa) in accordance with ASTM E 283. For curtain walls and storefront glazing, the maximum air leakage rate shall be 0.3 cubic foot per minute per square foot (cfm/ft2) (5.5 m3/h m2) of fenestration area. For commercial glazed swinging entrance doors and revolving doors, the maximum air leakage rate shall be 1.00 cfm/ft2 (18.3 m3/h m2) of door area when tested in accordance with ASTM E Sealing of the building envelope. Openings and penetrations in the building envelope shall be sealed with caulking materials or closed with gasketing systems compatible with the construction materials and location. Joints and seams shall be sealed in the same manner or taped or covered with a moisture vapor-permeable wrapping material. Sealing materials spanning joints between construction materials shall allow for expansion and contraction of the construction materials. 26 IECC Commercial Building Envelope Air Leakage Requirements 2006 / 2009 Sealing of the building envelope. Openings and penetrations in the building envelope shall be sealed with caulking materials or closed with gasketing systems compatible with the construction materials and location. Joints and seams shall be sealed in the same manner or taped or covered with a moisture vaporpermeable wrapping material. Sealing materials spanning joints between construction materials shall allow for expansion and contraction of the construction materials C Air barriers. A continuous air barrier shall be provided throughout the building thermal envelope. The air barriers shall be permitted to be located on the inside or outside of the building envelope, located within the assemblies composing the envelope, or any combination thereof. The air barrier shall comply with Sections C and C Exception: Air barriers are not required in buildings located in Climate Zones 1, 2 and 3. C Materials. Materials with an air permeability no greater than cfm/ft 2 (0.02 L/s m 2 ) under a pressure differential of 0.3 inches water gauge (w.g.) (75 Pa) when tested in accordance with ASTM E 2178 shall comply with this section.. Air barrier compliance options. C Assemblies. Assemblies of materials and components with an average air leakage not to exceed 0.04 cfm/ft 2 (0.2 L/s m 2 ) under a pressure differential of 0.3 inches of water gauge (w.g.)(75 Pa) when tested in accordance with ASTM E 2357, ASTM E 1677 or ASTM E 283 shall comply with this section C Building test. The completed building shall be tested and the air leakage rate of the building envelope shall not exceed 0.40 cfm/ft2 at a pressure differential of 0.3 inches water gauge (2.0 L/s m2 at 75 Pa) in accordance with ASTM E 779 or an equivalent method approved by the code official. 9

10 Internal Use Only ASRAE 90.1 Envelope Air Leakage Requirements Building Envelope Sealing. The following areas of the building envelope shall be sealed, caulked, gasketed, or weather-stripped to minimize air leakage: Continuous Air Barrier. The entire building envelope shall be designed and constructed with a continuous air barrier. Air barrier compliance options. Exceptions to : a. Semiheated spaces in climate zones 1 thru 6. b. Single wythe concrete masonry buildings in climate zone 2B Air Barrier Design. The air barrier shall be designed and noted in the following manner: a. All air barrier components of each building envelope assembly shall be clearly identified or otherwise noted on construction documents. b. The joints, interconnections, and penetrations of the air barrier components including lighting fixtures shall be detailed or otherwise noted. c. The continuous air barrier shall extend over all surfaces of the building envelope (at the lowest floor, exterior walls, and ceiling or roof). d. The continuous air barrier shall be designed to resist positive and negative pressures from wind, stack effect, and mechanical ventilation Air Barrier Installation The following areas of the continuous air barrier in the building envelope shall be wrapped, sealed, caulked, gasketed, or taped in an approved manner to minimize air leakage: Materials that have an air permeance not exceeding cfm/ft2 under a pressure differential of 0.3 in. w.g. (1.57psf) when tested in accordance with ASTM E Assemblies of materials and components (sealants, tapes, etc.) that have an average air leakage not to exceed 0.04 cfm/ft2 under a pressure differential of 0.3 in. w.g. (1.57psf) when tested in accordance with ASTM E 2357 ASTM E 1677, ASTM E 1680 or ASTM E283; North America Air Barrier Standards Performance Requirements Air Infiltration Requirements 0.3 in w.g.] Codes & Standards Material (ASTM E2178) Assembly (ASTM E2357 or E1677) Whole Building (ASTM E779) 1995 NBC (National Building Code of Canada) Massachusetts Energy Code (2001) Minnesota Energy Code (2009) New ampshire Energy Code (2009) Georgia Energy Code (2009) Rode Island Energy Code (2009) Oregon Energy Code (2009) Washington Energy Code (2010) ASRAE 90.1 (1) & 189.1P (2) US Army Corps of Engineers (3) Washington State; Seattle, WA or AND GSA (4) IgCC (5) (1)ASRAE , Continuous Air Barrier mandatory requirement ; (2) ASRAE 189.1P, Sustainable Buildings Standard 1st PUBLISED version, Jan. 22, 2010 (3) US Army Corps of Engineers (USACE) Building Envelope Airtightness Standard (4) GSA P100 published Jan 2011; (5) IGCC version 1 published March 2010; Final publication target date, C Materials. Materials with an air permeability no greater than cfm/ft2 (0.02 L/s m2) under a pressure differential of 0.3 inches water gauge (w.g.) (75 Pa) when tested in accordance with ASTM E 2178 shall comply with this section. E. I. DuPont de Nemours and Company All rights reserved Materials in Items 1 through 15 shall be deemed to comply with this section provided joints are sealed and materials are installed as air barriers in accordance with the manufacturer s instructions. 1. Plywood with a thickness of not less than 3/8 inch (10 mm). 2. Oriented strand board having a thickness of not less than 3/8 inch (10 mm). 3. Extruded polystyrene insulation board having a thickness of not less than 1/2 inch (12 mm). 4. Foil-back polyisocyanurateinsulation board having a thickness of not less than 1/2 inch (12 mm). 5. Closed cell spray foam a minimum density of 1.5 pcf(2.4 kg/m3) having a thickness of not less than 11/2 inches (36 mm). 6. Open cell spray foam with a density between 0.4 and 1.5 pcf(0.6 and 2.4 kg/m3) and having a thickness of not less than 4.5 inches (113 mm). 7. Exterior or interior gypsum board having a thickness of not less than 1/2 inch (12 mm). 8. Cement board having a thickness of not less than 1/2 inch (12 mm). 9. Built up roofing membrane. 10. Modified bituminous roof membrane. 11. Fully adhered single-ply roof membrane. 12. A Portland cement/sand parge, or gypsum plaster having a thickness of not less than 5/8 inch (16 mm). 13. Cast-in-place and precast concrete. 14. Fully grouted concrete block masonry. 15. Sheet steel or aluminum

11 Air Barrier Materials ASTM E2178 Current method is defined for flexible sheet and rigid boards. Standard specimen preparation for fluid applied materials still being developed. Diagram from CCMC Technical Guide for Air Barrier Materials Testing Internal Use Only Code Evaluation Reports C Assemblies. Assemblies of materials and components with an average air leakage not to exceed 0.04 cfm/ft2 (0.2 L/s m2) under a pressure differential of 0.3 inches of water gauge (w.g.)(75 Pa) when tested in accordance with ASTM E 2357, ASTM E 1677 or ASTM E 283 shall comply with this section. Assemblies listed in Items 1 and 2 shall be deemed to comply provided joints are sealed and requirements of Section C are met. 1. Concrete masonry walls coated with one application either of block filler and two applications of a paint or sealer coating; 2. A Portland cement/sand parge, stucco or plaster minimum 1/2 inch (12 mm) in thickness

12 E283 Basic air leakage test E1677 Specified opaque assembly Structural loading Option for water resistance testing (Type I) E2357 Specified opaque assembly w/ penetrations and interfaces Structural loading 34 ASTM E1677: Two Air Barrier Classifications Performance Properties Air leakage As tested by E283 Structural Integrity As tested by E330 Water Resistance As tested by E331 Water Vapor Permeance As tested by E96A Type I AB Classifications < Pa Type II 2 in. 2 0 or 500 Pa (65 mph) for 1 hr in each direction No penetration for 15 min of simulated wind driven O or 27 Pa (15 mph) Measured Not Required ASTM E1677 vs. ASTM E2357 Number of Test Specimen and configuration ASTM E ASTM E One Specimen: Test two of the three Specimens Opaque Wall (8 x 8-ft walls) (8 x 8 -ft walls): (fasteners to simulate wood siding or brick 1 Opaque Wall ties required) 2 Wall with penetrations 3 Wall-Foundation Interface Conditions for Air Leakage Testing Pressure Loading Schedule Five Test Pressures: 75Pa (1.56 psf, 25 mph) two pressures below 75 Pa two pressures above 75 Pa Air leakage results are reported at 75Pa (Positive & negative pressures) Sustained loads up to +/- 500 Pa (10.4 psf, 65 mph) (Positive & negative pressures) Seven Test Pressures: +/- 25Pa (0.56 psf, 15 mph) +/- 50Pa (1.04 psf, 20 mph) +/- 75Pa (1.56 psf, 25 mph) +/- 100Pa (2.09 psf, 30 mph) +/- 150Pa (3.24 psf, 35 mph) +/- 250Pa (5.23 psf, 45 mph) +/- 300Pa (6.24 psf, 50 mph) (Positive & negative pressures) 1 - Sustained, +/- 600Pa (12.5 psf, 71 mph) 2 - Cyclic, +/- 800 Pa (16.7 psf, 82 mph) 3 - Gust, +/ (25 psf, 100 mph) (Positive & negative pressures) 12

13 C Building test. The completed building shall be tested and the air leakage rate of the building envelope shall not exceed 0.40 cfm/ft2 at a pressure differential of 0.3 inches water gauge (2.0 L/s m2 at 75 Pa) in accordance with ASTM E 779 or an equivalent method approved by the code official. 37 Residential: IECC Air leakage. (Mandatory) Building thermal envelope. The building thermal envelope shall be durably sealed to limit infiltration. The sealing methods between dissimilar materials shall allow for differential expansion and contraction. The following shall be caulked, gasketed, weatherstripped or otherwise sealed with an air barrier material, suitable film or solid material: 1. All joints, seams and penetrations. 2. Site-built windows, doors and skylights. 3. Openings between window and door assemblies and their respective jambs and framing. 4. Utility penetrations. 5. Dropped ceilings or chases adjacent to the thermal envelope. 6. Knee walls. 7. Walls and ceilings separating a garage from conditioned spaces. 8. Behind tubs and showers on exterior walls. 9. Common walls between dwelling units. 10. Other sources of infiltration Fenestration air leakage. Windows, skylights and sliding glass doors shall have an air infiltration rate of no more than 0.3 cfm per square foot (1.5 L/s/m2), and swinging doors no more than 0.5 cfm per square foot (2.6 L/s/m2), when tested according to NFRC 400 or AAMA/WDMA/ CSA101/I.S.2/A440 by an accredited, independent laboratory and listed and labeled by the manufacturer. Exceptions: Site-built windows, skylights and doors Recessed lighting. Recessed luminaires installed in the building thermal envelope shall be sealed to limit air leakage between conditioned and unconditioned spaces by being: 1. IC-rated and labeled with enclosures that are sealed or gasketed to prevent air leakage to the ceiling cavity or unconditioned space; or 2. IC-rated and labeled as meeting ASTM E 283 when tested at 1.57 psi (75 Pa) pressure differential with no more than 2.0 cfm (0.944 L/s) of air movement from the conditioned space to the ceiling cavity; or 3. Located inside an airtight sealed box with clearances E. I. of DuPont at least de 0.5 Nemours inch (12.7 and mm) Company from combustible All rights material reserved38 and 3 inches (76 mm) from insulation. Internal Use Only IECC Residential Building Envelope Air Leakage Requirements Compliance options: Checklist or Testing < 7 AC 50 Qualitative requirement and location list Qualitative requirement and location list

14 Residential: IECC-2009 R Building thermal envelope. The building thermal envelope shall be durably sealed to limit infiltration. The sealing methods between dissimilar materials shall allow for differential expansion and contraction. The following shall be caulked, gasketed, weatherstripped or otherwise sealed with an air barrier material, suitable film or solid material: 1. All joints, seams and penetrations. Site-built windows, doors and skylights. 3. Openings between window and door assemblies and their respective jambs and framing. 4. Utility penetrations. 5. Dropped ceilings or chases adjacent to the thermal envelope. 6. Knee walls. 7. Walls and ceilings separating a garage from conditioned spaces. 8. Behind tubs and showers on exterior walls. 9. Common walls between dwelling units. 10. Attic access openings. 11. Rim joist junction. 12. Other sources of infiltration. 40 Residential: IECC-2009 R Air sealing and insulation. Building envelope air tightness and insulation installation shall be demonstrated to comply with one of the following options given by Section or : Testing option. Building envelope tightness and insulation installation shall be considered acceptable when tested air leakage is less than seven air changes per hour (AC) when tested with a blower door at a pressure of 33.5 psf (50 Pa). Testing shall occur after rough in and after installation of penetrations of the building envelope, including penetrations for utilities, plumbing, electrical, ventilation and combustion appliances. During testing: 1. Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed; 2. Dampers shall be closed, but not sealed, including exhaust, intake, makeup air, backdraft and flue dampers; 3. Interior doors shall be open; 4. Exterior openings for continuous ventilation systems and heat recovery ventilators shall be closed and sealed; 5. eating and cooling system(s) shall be turned off; 6. VAC ducts shall not be sealed; and 7. Supply and return registers shall not be sealed Visual inspection option. Building envelope tightness and insulation installation shall be considered acceptable when the items listed in Table , applicable to the method of construction, are field verified. Where required by the code official, an approved party independent from the installer of the insulation shall inspect the air barrier and insulation. 41 Internal Use Only 14

15 Internal Use Only IECC Residential Building Envelope Air Leakage Requirements Compliance options: Checklist or Testing < 7 AC 50 Compliance options: Checklist and Testing Z1,2: < 5AC 50 Z3-8:: < 3AC 50 Qualitative requirement and location list Qualitative requirement and location list Residential: IECC-2012 R402.4 Air leakage (Mandatory). R402.4 Air leakage (Mandatory). The building thermal envelope shall be constructed to limit air leakage in accordance with the requirements of Sections R through R R Building thermal envelope. The building thermal envelope shall comply with Sections R and R The sealing methods between dissimilar materials shall allow for differential expansion and contraction. R Installation. The components of the building thermal envelope as listed in Table R shall be installed in accordance with the manufacturer s instructions and the criteria listed in Table R , as applicable to the method of construction. Where required by the code official, an approved third party shall inspect all components and verify compliance. R Testing. The building or dwelling unit shall be tested and verified as having an air leakage rate of not exceeding 5 air changes per hour in Climate Zones 1 and 2, and 3 air changes per hour in Climate Zones 3 through 8. Testing shall be conducted with a blower door at a pressure of 0.2 inches w.g. (50 Pascals). Where required by the code official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and provided to the code official. Testing shall be performed at any time after creation of all penetrations of the building thermal envelope. During testing: 1. Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed, beyond the intended weatherstripping or other infiltration control measures; 2. Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed beyond intended infiltration control measures; 3. Interior doors, if installed at the time of the test, shall be open; 4. Exterior doors for continuous ventilation systems and heat recovery ventilators shall be closed and sealed; 5. eating and cooling systems, if installed at the time of the test, shall be turned off; and 6. Supply and return registers, if installed at the time of the test, shall be fully open. 44 Air Barrier Test Methods and Usage Product Testing Assembly Testing As-built Testing ABAA.004 cfm/ft² at.3 in. 2O Certification (.02 L/(s Pa) IECC(2012) Residential IECC (2012) Commercial ASTM E2178 ASTM E2357 ASTM E779,.004 cfm/ft² at.3 in. 2O (.02 L/(s Pa) &.04 cfm/ft² at.3 in. 2O (.2 L/(s m²)@75 Pa).04 cfm/ft² at.3 in. 2O (.2 L/(s m²)@75 Pa) 5 AC 50 (Climate Zones 1&2) 3 AC 50 (Climate Zones 3-8).4 cfm/ft 2 at.3 in. 2O USACE Specification.004 cfm/ft² at.3 in. 2O (.02 L/(s Pa) &.25 cfm/ft 2 at.3 in. 2O (modified by USACE protocol) 15

16 Air Barrier Performance Material Properties Air Infiltration Resistance Vapor Permeability Durability Installation Continuity Structural Integrity Durability E. I. DuPont de Nemours and Company All rights reserved C Air barrier construction. The continuous air barrier shall be constructed to comply with the following: 1. The air barrier shall be continuous for all assemblies that are the thermal envelope of the building and across the joints and assemblies. 2. Air barrier joints and seams shall be sealed, including sealing transitions in places and changes in materials. Air barrier penetrations shall be sealed in accordance with Section C The joints and seals shall be securely installed in or on the joint for its entire length so as not to dislodge, loosen or otherwise impair its ability to resist positive and negative pressure from wind, stack effect and mechanical ventilation. 47 Continuity: Air Barrier System The building envelope must be designed and constructed with a continuous air barrier: Primary Air Barrier Membranes Installation & Continuity Accessories: fasteners, adhesives & primers, tapes, flashing, transition membranes, caulks & sealants, etc 16

17 Structural Integrity Air barriers must be able to withstand pressure loads (from wind, stack effect and mechanical system) or be able to transfer the loads to other elements of the building enclosure without rupture or displacement. Durability Air Barriers must withstands environmental exposures: UV* (NOT to exceed manufacturer s recommendation for UV exposure) Thermal exposure & thermal cycling Repeated exposure to water Abrasion Mechanical stresses * Most air barrier membranes are not designed for continuous UV exposure Tested Systems + = Window and Wall usually tested separately, should be tested as installed unit. E. I. DuPont de Nemours and Company All rights reserved 17

18 Material deformation and loss of adhesion Joints open E. I. DuPont de Nemours and Company All rights reserved 18

19 Taped rigid insulation is not allowed as an air barrier in Wisconsin. When some types of insulation boards get colder by 70oF, they can shrink ¼ on all sides. The tape cannot adequately perform under such circumstances. - Air Barrier Update, International Masonry Institute Technology Brief, January Energy efficiency Structural performance Fire resistance Water management NFPA 285: Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Non-Load Bearing Wall Assemblies Containing Combustible Components. Tests fire performance of the wall assembly to be used on a project. Required by code when certain combustible materials are specified to be used in a non-combustible wall assembly Applies to exterior walls of Type I-IV Construction Triggered by when specific combustible materials are specified components of the wall assembly: Combustible insulation (pre-2012 IBC) Combustible claddings (pre-2012 IBC & 2012 IBC) Combustible air & water barriers (2012 IBC) Vertical and Lateral Flame Propagation. Exterior walls on buildings of Type I, II, III or IV construction that are greater than 40 feet (12192 mm) in height above grade plane and contain a combustible water-resistive barrier shall be tested in accordance with and comply with the acceptance criteria of NFPA

20 NFPA 285 Triggers Mechanical equipment screens located on roof decks constructed of combustible materials ( ) igh-pressure Decorative Exterior- Grade Compact Laminates (PL) used as exterior wall coverings ( ) Metal composite materials (MCM), such as ACM, used as exterior wall coverings ( ) Foam plastic insulation ( ) Fiber-reinforced polymer (FRP) used on exterior walls (2612.6) Metal composite materials (MCM), such as ACM, used as exterior wall coverings ( ) Foam plastic insulation ( ) Fiber-reinforced polymer (FRP) used on exterior walls (2612.5) Metal composite materials (MCM), such as ACM, used as exterior wall coverings ( ) Foam plastic insulation ( ) Combustible water resistive barrier (1403.5) Water Management Minimize Maximize Wetting 1.Bulk Water 2. Air transport 3. Diffusion Drying 1. Drainage 2. Venting 3. Diffusion Good enclosure water management design and detailing will minimize the risk of wetting, but drying potential must ALWAYS be considered Air Barriers, Water-resistive Barriers and Vapor Barriers Air barriers can be placed anywhere in the wall. Water-resistive Barrier Vapor Barrier 20

21 Air Transported Moisturemust not be confused with Vapor Diffusion Air Transported Moisture P o > P i Water Vapor Diffusion VP* o > VP* i 98% of all water vapor migration Free ride ~ 2% of all water vapor Slow Molecular migration Movement * Vapor pressure is proportional to Water Vapor Concentration E. I. DuPont de Nemours and Company All rights reserved Where are interior vapor retarders required? 2006: Above Blue Line 2003: Above White Line 21

22 SECTION 8 International Residential Code (2009/ 2012): Condensation Protection Requirements R702.7 Vapor retarders. Class I or II vapor retarders are required on the interior side of frame walls in Climate Zones 5, 6, 7, 8 and Marine 4. Exceptions: 1. Basement walls. 2. Below grade portion of any wall. 3. Construction where moisture or its freezing will not damage the materials. SECTION 8 Since IBC 2009 Class III Vapor Retarders allowed in cold climates Includes vinyl and brick with airspace Specific sheathing R-Values dependent on climate. SECTION 8 International Residential Code (2009/2012): Condensation Protection Requirements R Class III vapor retarders. Class III vapor retarders shall be permitted where any one of the conditions in Table R is met. R Material vapor retarder class. The vapor retarder class shall be based on the manufacturer s certified testing or a tested assembly. The following shall be deemed to meet the class specified: Class I: Sheet polyethylene, unperforated aluminum foil. Class II: Kraft-faced fiberglass batts. Class III: Latex or enamel paint. R Minimum clear air spaces and vented openings for vented cladding. For the purposes of this section, vented cladding shall include the following minimum clear air spaces. Other openings with the equivalent vent area shall be permitted. 1. Vinyl lap or horizontal aluminum siding applied over a weather resistive barrier as specified in Table R Brick veneer with a clear airspace as specified in Table R Other approved vented claddings. 22

23 Total Moisture Content of Wall System Simulated 3 months starting July 1. Data originally submitted to Texas Residential Constuction Council Task-Group on Mold and Moisture Gypsum Board R Simulated 3 months starting July 1. Data originally submitted to Texas Residential Constuction Council Task-Group on Mold and Moisture New Language 2015 IBC Vapor retarders. Vapor retarders as described in Section shall be provided in accordance with Sections and , or an approved design using accepted engineering practice for hygrothermalanalysis Class I and II Vapor Retarders. Class I or II vapor retarders shall not be provided on the interior side of frame walls in Zones 1 and 2. Class I vapor retarders shall not be provided on the interior side of frame walls in Zones 3 and 4. Class I or II vapor retarders shall be provided on the interior side of frame walls in Zones 5, 6, 7, 8 and Marine 4. The appropriate zone shall be selected in accordance with Chapter 3 of the International Energy Conservation Code. Exceptions: 1. Basement walls. 2. Below-grade portion of any wall. 3. Construction where moisture or its freezing will not damage the materials. 4. Conditions where Class III vapor retarders are required in Section Class III vapor retarders. Class III vapor retarders shall be permitted where any one of the conditions in Table is met. Only Class III vapor retarders shall be used on the interior side of frame walls where foam plastic insulating sheathing with perm rating of less than 1 perm is applied in accordance with Table on the exterior side of the frame wall. 23

24 Section 3: Whole Building Airtightness: Blower Door Testing and Diagnostic Tool 3 Building Test ASTM E779 SECTION 3 US ome Airtightness Source: 2009 ASRAE andbook of Fundamentals 24

25 SECTION 3 LBNL Data Base SECTION 3 Source: LBNL Report Number 53367: Chan, W. R, et al, Analysis of U.S. Residential Air Leakage Database, Indoor Environment Department, Lawrence Berkeley National Laboratory, July 2003 E. I. DuPont de Nemours and Company All rights reserved SECTION 3 Normalized Leakage of U.S. omes Normalized leakage (NL) is the measure of air leakage used in ResDB. Roughly speaking, NL = 0.55 corresponds to AC50 = 10 (i.e. 10 air changes per hour at a pressure difference of 50 Pa). ome Counts NL Geometric Mean NL Geometric Standard Deviation Single-Family Detached omes Single-Family Attached omes 135, , Multi-Family omes 2, Manufactured omes 8, E. I. DuPont de Nemours and Company All rights reserved 25

26 Residential Air Leakage Sequential Testing: IBACOS Lab ouse Stage ousewrap installed: Window and door openings andother penetrations integrated with air barrier and drainage plane After spray foam installed in attic, strategically sealing penetrations in 2 nd floor ceiling plane Tested Air Leakage 3.0 AC 50 ousewrap as primary air barrier required great attention to detail but it worked 0.88 AC 50 After spray foam in the band joists 0.77 AC 50 After wall cavity insulation and drywall installed 0.65 AC 50 Complete 0.54 AC 50 Ultimate target was Passivhaus level of airtightness, which is 0.6 Source: Oberg, B, Energy Efficiency Lab ome: Case Study, EEBA Conference, September SECTION 3 Whole Building Airtightness Testing: US Army Corps of Engineers (USACE) Standard All new buildings must: 1. Achieve an air leakage rate not to exceed 0.25 cfm/ft 75Pa 2. Pass an air leakage test per ASTM E779 26

27 3 USACE Standard Experience Current USACE Standard (0.25 cfm/ft 75Pa ) Future USACE Standard: (0.15 cfm/ft 75Pa ) Up to 80% more airtight than current USACE Standard Source: Dr. Alexander Zhivov, USACE ERDC, Champaign, USA: AIVC Workshop, June 14, 2010, Brussels, Belgium 3 Implementing USACE Air tightness Requirements: A General Contractor s Perspective Follow the details know what items are part of the continuous air barrier; attention to detail is critical in design and construction Materials compatibility make sure the materials specified are compatible Manufacturers installation instruction engage manufacturers representatives for training, site visits, inspections Verify & document make sure that the details are being followed. Sealing the envelope is cheap during construction but more expensive afterwards (cost 10 to 1000X more afterwards). Source: ensel Phelps Construction Co. SECTION 3 27

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