Wall Insulation

Technology Fact Sheet

Side stapled WALL INSULATION insulation batt (stapled no Prefer more than ¼" face stapled STEPS FOR EFFECTIVE WALL from edge) insulation batt For more information, contact: Cut out WALL INSULATION CONSTRUCTION AND INSULATION Back of batt batt to Unfaced split around fit snugly 1. Review the plans and specifications and insulation wire around Energy Efficiency and wall Provide Moisture Control and Insulation in Wall Systems Renewable Energy identify all walls (including bandjoists) outlet Clearinghouse (EREC) between conditioned (heated and cooled) Durable roof with 1-800-DOE-3732 overhang spaces and unconditioned spaces FACED EFFECTIVE WALL INSULATION A drainage plane in a www.eren.doe.gov Tape joint (exterior, attics, crawl spaces, garages, and Properly sealed, moisture-protected, and wall system creates FACED Or visit the BTS Web site at Flash an easy pathway for mechanical rooms). Use advanced framing insulated walls help increase comfort, windows and www.eren.doe.gov/buildings FACED other techniques to increase insulation levels reduce noise, and save on energy costs. openings water to drain away 2 Stud Or refer to the Builder’s Guide “energy corner” Gutters and reduce lumber use. UNFACED However, walls are the most complex connected to from the house. with drywall clips downspouts Energy Efficient Building that drain 2. Use diagonal corner bracing (let-in component of the building envelope to water Association, Inc. Subfloor Buildings for away from Studs and insulate, air seal, and control moisture. the house insulation 651-268-7585 bracing) on exterior walls to substitute Caulk bottom plate or use sill gasket the 21st Century www.eeba.org for corner plywood sheathing and The keys to an effective wall are: Tape joints Floor joist in foam ½" x 2" Strips allow continuous insulated sheathing. Insulate and air seal Buildings that are more sheathing Written and prepared for band joist area • Airtight construction—all air leaks ½" Sheathing the U.S. Department of between floors energy efficient, comfortable, 3. Use foam sheathing for insulating Adhesive or sealed in the wall during construction ½" Gap Energy by: caulk and affordable…that’s the behind siding headers to reduce framing heat loss. and prior to insulation installation. Extend sheathing Siding 9. Obtain full coverage of batt or blown wall goal of DOE’s Office of Building below bottom plate Southface Energy Institute 4. Seal all air leaks through walls before Technology, State and • Moisture control—exterior rain drain and seal 404-872-3549 insulation. Cut batt insulation to fit snugly Siding primed on all six faces (front, back, edges) to improve durability www.southface.org insulating, including under the bottom plate, into non-standard stud spaces and to com- Community Programs (BTS). age system, continuous air barrier, and band joist areas between floors, electrical pletely fill cavity. To accelerate the development vapor barrier located on the P REVENT RAIN PENETRATION U.S. Department of Energy’s and wide application of energy Oak Ridge boxes, and all electrical, plumbing, and HVAC appropriate side of the wall. Causes of rain leaks through exterior walls 10. Slit batt insulation to fit around the back and efficiency measures, BTS: National Laboratory penetrations. front side of electrical wiring and plumbing • Complete insulation coverage—advanced include improper installation of siding Buildings Technology Center • Conducts R&D on technologies 5. Use caulk and backer rod or non-expanding without compressing or tearing the framing to maximize insulation coverage and materials; poor-quality flashing, 423-574-5178 and concepts for energy effi spray foam, not insulation, to seal around insulation. reduce thermal bridging, no gaps or weatherstripping, or caulking around joints in www.ornl.gov/ORNL/BTC ciency, working closely with window and door jambs. compressed insulation, and continuous the building exterior (such as windows, doors, 11. Notch out batt insulation around electrical boxes the building industry and with The Model Energy Code 6. If fixtures such as stairs or shower/tub insulated sheathing. and bottom plates); and wind-driven rain that can be obtained from the and use scraps to insulate behind the box. manufacturers of materials, penetrates the exterior finish. To enhance pro enclosures cover exterior walls and do not equipment, and appliances International Code Council by 12. Once the interior drywall is in place, seal all AIR SEALING calling 703-931-4533 allow easy installation of insulation after the tection against rain penetration, create a drain penetrations with durable caulking. • Promotes energy/money Air sealing reduces heat flow from air move sheathing is attached, insulate behind these age plane within the wall system of the home. MECcheck, a companion saving opportunities to both ment (convection) and prevents water vapor in compliance software components in advance using R-13 or R-19 Fiberglass Batt Insulation builders and buyers of homes the air from entering the wall. In a 100-square C ONTROL MOISTURE IN WALLS package, can be ordered from batts and cover with a weatherproof barrier and commercial buildings Characteristics foot wall, one cup of water can diffuse through All climates require these steps: DOE by calling (½-inch drywall, plastic, or other sheet 1-800-270-CODE • Works with state and local drywall without a vapor barrier in a year, but 50 material). Thickness R-value Cost • Install a polyethylene ground cover on or downloaded directly regulatory groups to improve cups can enter through a ½-inch, round hole. (inches)(¢/sq.ft.) the earth floor of houses with crawl from the Web at 7. Select insulation levels based on the MEC 3½ 11 12-16 building codes, appliance stan In fact, sealing air leaks is 10 to 100 times as www.energycodes.org/ 5 spaces and slope the ground away from and the DOE Insulation Fact Sheet. 3 /8 13 15-20 dards, and guidelines for effi important as installing a vapor barrier. resid/resid.htm. 3½ 15 (high density) 34-40 cient energy use the foundations of all houses. 8. Face-staple batts because side stapling 6 to 6¼ 19 27-34 MOISTURE CONTROL • Install a continuous vapor barrier that has a NOTICE: Neither the United creates channels for air flow and compresses 5¼ 21 (high density)33-39 • Provides support and grants States government nor any to states and communities Air sealing and moisture control make insulation Perm rating of less than one (see page 3). the insulation, thus reducing the R-value. If 8 to 8½ 25 37-45 agency thereof, nor any of their 8 30 (high density) 45-49 for deployment of energy- more effective. It is a myth that installing vapor employees, makes any warranty, face stapling is not an option, use unfaced • Place a termite shield, sill gaskets, or 9½ 30 (standard)39-43 express or implied, or assumes efficient technologies and barriers is the most important step for control other vapor-impermeable membrane on batts or carefully side staple within ¼ inch 12 38 55-60 any legal liability or responsibility practices ling moisture in walls. Vapor barriers only retard of the stud face. This chart is for comparison only. Determine actual the top of the foundation wall. This for the accuracy, completeness, moisture due to diffusion, while most moisture or usefulness of any information, thickness, R-value, and cost from manufacturer or local action will prevent moisture from wicking apparatus, product, or process building supply. enters walls either through fluid capillary action into the framed wall from the concrete disclosed. The views and opin- or as water vapor through air leaks. foundation wall by capillary action. ions of authors expressed herein do not necessarily state or reflect Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 20% postconsumer waste. those of the United States gov- OFFICE OF BUILDING TECHNOLOGY, STATE AND COMMUNITY PROGRAMS October 2000 DOE/GO-102000-0772 ernment or any agency thereof. ENERGY EFFICIENCY AND RENEWABLE ENERGY • U.S. DEPARTMENT OF ENERGY

Wall DOE 772 MS.p65 1 10/30/00, 11:10 AM WALL INSULATION WALL FRAMING WITH ADVANCED FRAMING TECHNIQUES homes with more window and door area. Another factor to • Foam-in-place insulation can be blown into walls and Building experts have performed considerable research on ways INSULATED HEADERS AND LET-IN BRACING consider is that the interior finish or exterior siding may bow reduces air leakage. Some types use carbon dioxide in the to reduce the amount of lumber in our homes while maintaining Insulated headers slightly between studs when using 24-inch centers. manufacturing process rather than more environmentally structural integrity. The U.S. Forestry Products Association and harmful gases such as pentane or hydrochlorofluorocarbons. Double other organizations have devised an “ optimum value engineer top plate WHAT TYPE OF INSULATION SHOULD I USE? ing” (OVE) framing system that reduces unnecessary lumber The home designer has an increasing array of insulation WALL SHEATHINGS ½" foam sheathing use and improves the whole-wall R-value by reducing thermal cut to fill void products from which to choose to insulate wood-framed walls. Some builders use ½-inch wood sheathing (R-0.6) or asphalt- bridging and maximizing the wall area that is insulated. Selected The wide variety of insulation materials often makes it difficult impregnated sheathing, usually called blackboard (R-1.3), to OVE practices include: to determine the most cost-effective products and techniques. cover the exterior framing before installing siding. Instead,

½ Refer to the Model Energy Code (MEC) or DOE Insulation Fact consider using ½-inch foam insulated sheathing (R-2 to R-3.5). " 1½" + ½ "+ 1½" = 3½" 2" of foam sheathing • Design the house to use materials efficiently by employing 1½" 1½ or fiberglass batt " Sheet for R-value recommendations for your climate and build- Sheathing thicker than ½ inch will yield even higher R-values. simpler shapes and volumes, compact designs, and designs ing type. The DOE Insulation Fact Sheet (DOE/CE-0180) can be based on a 2-foot module. Foam sheathing has these advantages: Let-in bracing ordered from the Energy Efficiency and Renewable Energy • Frame at 24-inch rather than 16-inch centers. • The continuous layer of insulation reduces thermal bridging Metal T-bracing nailed to studs Clearinghouse or accessed from the Internet at www.ornl.gov/ saves on the labor cost of 1x4 through wood studs, saving energy and improving comfort. • Design headers for loading conditions and use insulated headers. let-in bracing roofs+walls. • It is easier to cut and install than heavier weight sheathing • Locate window and door openings in-line with established • Fiberglass and rock wool batts— 2x4 walls can hold R-13 or 2x4 or 2x6 stud products. framing and size windows to fit within existing stud spacing. 1x4 let-in brace notched R-15 batts; 2x6 walls can have R-19 or R-21 products. into wall studs Saw kerf for T-brace • It protects against condensation on the inside wall by keeping • Eliminate unnecessary framing at intersections using two-stud Generally, batt insulation is the least expensive wall insulation K-brace when window the interior of the wall warmer. rather than three-stud corners and ladder blocking where or door is near corner material but requires careful installation for effective interior partitions intersect exterior walls. performance (see page 4). • It usually costs less than plywood or oriented strand board (OSB). • Use let-in bracing to allow the use of insulated sheathing in corners. • Cellulose insulation, made from recycled newsprint, comes primarily in loose-fill form. It can be installed in walls using a Ensure that the sheathing completely covers, and is sealed to, • Eliminate curtailed studs (cripples) under windows. dry-pack process or a moist-spray technique. It generally costs the top plate and band joist at the floor. Most sheathing prod- • Align roof, wall, and floor framing members (studs and joists) more than batt insulation, but it offers reduced air leakage ucts come in 8-, 9-, or 10-foot lengths to allow complete cover- vertically throughout the structure so that a single top plate through the wall cavity plus improved sound deadening. age of the wall. Once it is installed, patch all holes, penetrations, 2X6 WALL CONSTRUCTION can be used. and seams with caulk or housewrap tape. In most code jurisdictions, 2x6’s can be spaced on 24-inch • Fiberglass and rock wool loose-fill insulation provide full centers, rather than 16-inch centers used for 2x4’s. The advan coverage with a “Blow-in Blanket” System (BIBS) that involves Because of its insulation advantages over plywood and OSB, STANDARD FRAMING VERSUS ADVANCED FRAMING tages of using 2x6 studs on 24-inch centers are: blowing insulation into open stud cavities behind a net. foam sheathing is best when used continuously in combination CROSS-SECTION with let-in bracing, which provides structural support similar to • The thicker wall cavity provides room for R-19 or R-21 wall • Rigid foam insulation has a higher R-value per inch Standard corner Standard T-wall intersection that offered by plywood or OSB. Some builders use two layers of Insulation void insulation. than fiberglass or cellulose and stops air leaks, but it is considerably more expensive. It is manufactured in sheathing— plywood or OSB for structural support and a seam- • Overall, thermal bridging through studs is reduced due to the sheet-good dimensions and is often used as the outer layer of staggered layer of rigid foam for insulation. When the total depth Extra studs for higher R-value of 2x6’s and less stud area in the wall. Extra exterior attaching drywall of the sheathing material exceeds ½ inch, make certain the corner studs insulation. • Less framing reduces labor costs. window and door jambs are adjusted for the total wall thickness. Standard methods use unnecessary studs • There is more space for insulating around piping, wiring, and Some flanged windows are readily adaptable to this approach.

areas with significant winters and homes in which windows and ○ In most cold climates, vapor barriers should be placed on the interior Perm Ratings of Different Materials Drywall and interior walls are attached to ○ Drywall clip to hold (warm-in-winter) side of walls. However, the map shows that in some (Rating of 1 or less qualifies as a vapor barrier) "ladder," which spans doors occupy 10 percent or less of the total wall area. Walls ○ drywall in place between studs

○ Asphalt-coated paper backing on insulation 0.40 with substantial window and door area may require almost as southern climates, the vapor ○ Polyethylene plastic (6 mil) 0.06

○ barrier should be omitted, while in Comparison Standard Advanced much framing as 2x4 walls because each opening can add extra

○ Plywood with exterior glue 0.70 Insulation Voids 3% 0% hot and humid climates, such as studs. Additionally, the window and door jambs must be wider, ○ Interior Plastic-coated insulated foam sheathing 0.4 to 1.2

Framing factor 15-25% 10-15% ○ along the Gulf coast and in Florida, Aluminum foil (.35 mil) 0.05 Batt R-value R-13 R-13 requiring the purchase of a jamb extender that increases costs ○

○ the vapor barrier should be placed Omit Vapor barrier paint or primer 0.45

(30% higher) Thicker insulated sheathing may be a less expensive way to ○ Drywall (painted - latex paint)2-3

○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ increase overall R-value than 2x6 construction, especially in

Wall DOE 772 MS.p65 2 10/30/00, 11:10 AM WALL INSULATION WALL FRAMING WITH ADVANCED FRAMING TECHNIQUES homes with more window and door area. Another factor to • Foam-in-place insulation can be blown into walls and Building experts have performed considerable research on ways INSULATED HEADERS AND LET-IN BRACING consider is that the interior finish or exterior siding may bow reduces air leakage. Some types use carbon dioxide in the to reduce the amount of lumber in our homes while maintaining Insulated headers slightly between studs when using 24-inch centers. manufacturing process rather than more environmentally structural integrity. The U.S. Forestry Products Association and harmful gases such as pentane or hydrochlorofluorocarbons. Double other organizations have devised an “optimum value engineer- top plate WHAT TYPE OF INSULATION SHOULD I USE? ing” (OVE) framing system that reduces unnecessary lumber The home designer has an increasing array of insulation WALL SHEATHINGS ½" foam sheathing use and improves the whole-wall R-value by reducing thermal cut to fill void products from which to choose to insulate wood-framed walls. Some builders use ½-inch wood sheathing (R-0.6) or asphalt- bridging and maximizing the wall area that is insulated. Selected The wide variety of insulation materials often makes it difficult impregnated sheathing, usually called blackboard (R-1.3), to OVE practices include: to determine the most cost-effective products and techniques. cover the exterior framing before installing siding. Instead,

½" 1½" + ½ "+ 1½" = 3½" Refer to the Model Energy Code (MEC) or DOE Insulation Fact consider using ½-inch foam insulated sheathing (R-2 to R-3.5). • Design the house to use materials efficiently by employing 1½" 2" of foam sheathing 1½" or fiberglass batt Sheet for R-value recommendations for your climate and build Sheathing thicker than ½ inch will yield even higher R-values. simpler shapes and volumes, compact designs, and designs ing type. The DOE Insulation Fact Sheet (DOE/CE-0180) can be based on a 2-foot module. Foam sheathing has these advantages: Let-in bracing ordered from the Energy Efficiency and Renewable Energy • Frame at 24-inch rather than 16-inch centers. • The continuous layer of insulation reduces thermal bridging Metal T-bracing nailed to studs Clearinghouse or accessed from the Internet at www.ornl.gov/ saves on the labor cost of 1x4 through wood studs, saving energy and improving comfort. • Design headers for loading conditions and use insulated headers. let-in bracing roofs+walls. • It is easier to cut and install than heavier weight sheathing • Locate window and door openings in-line with established • Fiberglass and rock wool batts—2x4 walls can hold R-13 or 2x4 or 2x6 stud products. framing and size windows to fit within existing stud spacing. 1x4 let-in brace notched R-15 batts; 2x6 walls can have R-19 or R-21 products. into wall studs Saw kerf for T-brace • It protects against condensation on the inside wall by keeping • Eliminate unnecessary framing at intersections using two-stud Generally, batt insulation is the least expensive wall insulation K-brace when window the interior of the wall warmer. rather than three-stud corners and ladder blocking where or door is near corner material but requires careful installation for effective interior partitions intersect exterior walls. performance (see page 4). • It usually costs less than plywood or oriented strand board (OSB). • Use let-in bracing to allow the use of insulated sheathing in corners. • Cellulose insulation, made from recycled newsprint, comes pri marily in loose-fill form. It can be installed in walls using a Ensure that the sheathing completely covers, and is sealed to, • Eliminate curtailed studs (cripples) under windows. dry-pack process or a moist-spray technique. It generally costs the top plate and band joist at the floor. Most sheathing prod • Align roof, wall, and floor framing members (studs and joists) more than batt insulation, but it offers reduced air leakage ucts come in 8-, 9-, or 10-foot lengths to allow complete cover vertically throughout the structure so that a single top plate through the wall cavity plus improved sound deadening. age of the wall. Once it is installed, patch all holes, penetrations, can be used. 2X6 WALL CONSTRUCTION In most code jurisdictions, 2x6’s can be spaced on 24-inch • Fiberglass and rock wool loose-fill insulation provide full and seams with caulk or housewrap tape. centers, rather than 16-inch centers used for 2x4’s. The advan- coverage with a “Blow-in Blanket” System (BIBS) that involves Because of its insulation advantages over plywood and OSB, STANDARD FRAMING VERSUS ADVANCED FRAMING tages of using 2x6 studs on 24-inch centers are: blowing insulation into open stud cavities behind a net. foam sheathing is best when used continuously in combination CROSS-SECTION • The thicker wall cavity provides room for R-19 or R-21 wall • Rigid foam insulation has a higher R-value per inch with let-in bracing, which provides structural support similar to Standard corner Standard T-wall intersection that offered by plywood or OSB. Some builders use two layers of Insulation void insulation. than fiberglass or cellulose and stops air leaks, but it is considerably more expensive. It is manufactured in sheathing—plywood or OSB for structural support and a seam- • Overall, thermal bridging through studs is reduced due to the sheet-good dimensions and is often used as the outer layer of staggered layer of rigid foam for insulation. When the total depth Extra studs for higher R-value of 2x6’s and less stud area in the wall. Extra exterior attaching drywall of the sheathing material exceeds ½ inch, make certain the corner studs insulation. • Less framing reduces labor costs. window and door jambs are adjusted for the total wall thickness. Standard methods use unnecessary studs • There is more space for insulating around piping, wiring, and Some flanged windows are readily adaptable to this approach.

Advanced corner 2x4 turned sideways Advanced ladder T-wall framing serves as nailer ductwork. for siding The economics of 2x6 wall construction is favorable primarily in VAPOR BARRIER PLACEMENT BY GEOGRAPHICAL LOCATION areas with significant winters and homes in which windows and ○ In most cold climates, vapor barriers should be placed on the interior PermPermPerm RatingsRatingsRatings ofofof DifferentDifferentDifferent Materials MaterialsMaterials Drywall and interior ○ walls are attached to Drywall clip to hold (warm-in-winter) side of walls. However, the map shows that in some (Rating of 1 or less qualifies as a vapor barrier) "ladder," which spans doors occupy 10 percent or less of the total wall area. Walls ○ drywall in place between studs

○ Asphalt-coated paper backing on insulation 0.40 with substantial window and door area may require almost as southern climates, the vapor ○ Polyethylene plastic (6 mil) 0.06

○ barrier should be omitted, while in Comparison Standard Advanced much framing as 2x4 walls because each opening can add extra

Framing factor 15-25% 10-15% ○ along the Gulf coast and in Florida, Aluminum foil (.35 mil) 0.05 Batt R-value R-13 R-13 requiring the purchase of a jamb extender that increases costs ○

○ the vapor barrier should be placed Omit Vapor barrier paint or primer 0.45

Sheathing R-value R-0.5 to 2.0 R-2.5 by $12 to $15 per opening. ○ vapor on the exterior of the wall. Exterior or Drywall (unpainted)50 Effective Average R-value R-11.1 R-14.6 ○ barrier no vapor barrier ○ (30% higher) Thicker insulated sheathing may be a less expensive way to Drywall (painted - latex paint)2-3 ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ increase overall R-value than 2x6 construction, especially in

Wall DOE 772 MS.p65 2 10/30/00, 11:10 AM Technology Fact Sheet

Side stapled WALL INSULATION insulation batt (stapled no Prefer more than ¼" face stapled STEPS FOR EFFECTIVE WALL from edge) insulation batt For more information, contact: Cut out WALL INSULATION CONSTRUCTION AND INSULATION Back of batt batt to Unfaced split around fit snugly 1. Review the plans and specifications and insulation wire around Energy Efficiency and wall Provide Moisture Control and Insulation in Wall Systems Renewable Energy identify all walls (including bandjoists) outlet Clearinghouse (EREC) between conditioned (heated and cooled) Durable roof with 1-800-DOE-3732 overhang spaces and unconditioned spaces FACED EFFECTIVE WALL INSULATION A drainage plane in a www.eren.doe.gov Tape joint (exterior, attics, crawl spaces, garages, and Properly sealed, moisture-protected, and wall system creates FACED Or visit the BTS Web site at Flash an easy pathway for mechanical rooms). Use advanced framing insulated walls help increase comfort, windows and www.eren.doe.gov/buildings FACED other techniques to increase insulation levels reduce noise, and save on energy costs. openings water to drain away 2 Stud Or refer to the Builder’s Guide “energy corner” Gutters and reduce lumber use. UNFACED However, walls are the most complex connected to from the house. with drywall clips downspouts Energy Efficient Building that drain 2. Use diagonal corner bracing (let-in component of the building envelope to water Association, Inc. Subfloor Buildings for away from Studs and insulate, air seal, and control moisture. the house insulation 651-268-7585 bracing) on exterior walls to substitute Caulk bottom plate or use sill gasket the 21st Century www.eeba.org for corner plywood sheathing and The keys to an effective wall are: Tape joints Floor joist in foam ½" x 2" Strips allow continuous insulated sheathing. Insulate and air seal Buildings that are more sheathing Written and prepared for band joist area • Airtight construction—all air leaks ½" Sheathing the U.S. Department of between floors energy efficient, comfortable, 3. Use foam sheathing for insulating Adhesive or sealed in the wall during construction ½" Gap Energy by: caulk and affordable…that’s the behind siding headers to reduce framing heat loss. and prior to insulation installation. Extend sheathing Siding 9. Obtain full coverage of batt or blown wall goal of DOE’s Office of Building below bottom plate Southface Energy Institute 4. Seal all air leaks through walls before Technology, State and • Moisture control—exterior rain drain- and seal 404-872-3549 insulation. Cut batt insulation to fit snugly Siding primed on all six faces (front, back, edges) to improve durability www.southface.org insulating, including under the bottom plate, into non-standard stud spaces and to com Community Programs (BTS). age system, continuous air barrier, and band joist areas between floors, electrical pletely fill cavity. To accelerate the development vapor barrier located on the P REVENT RAIN PENETRATION U.S. Department of Energy’s and wide application of energy Oak Ridge boxes, and all electrical, plumbing, and HVAC appropriate side of the wall. Causes of rain leaks through exterior walls 10. Slit batt insulation to fit around the back and efficiency measures, BTS: National Laboratory penetrations. front side of electrical wiring and plumbing • Complete insulation coverage— advanced include improper installation of siding Buildings Technology Center • Conducts R&D on technologies 5. Use caulk and backer rod or non-expanding without compressing or tearing the framing to maximize insulation coverage and materials; poor-quality flashing, 423-574-5178 and concepts for energy effi- spray foam, not insulation, to seal around insulation. reduce thermal bridging, no gaps or weatherstripping, or caulking around joints in www.ornl.gov/ORNL/BTC ciency, working closely with window and door jambs. compressed insulation, and continuous the building exterior (such as windows, doors, 11. Notch out batt insulation around electrical boxes the building industry and with The Model Energy Code 6. If fixtures such as stairs or shower/tub insulated sheathing. and bottom plates); and wind-driven rain that can be obtained from the and use scraps to insulate behind the box. manufacturers of materials, penetrates the exterior finish. To enhance pro- enclosures cover exterior walls and do not equipment, and appliances International Code Council by 12. Once the interior drywall is in place, seal all AIR SEALING calling 703-931-4533 allow easy installation of insulation after the tection against rain penetration, create a drain- penetrations with durable caulking. • Promotes energy/money Air sealing reduces heat flow from air move- sheathing is attached, insulate behind these age plane within the wall system of the home. MECcheck, a companion saving opportunities to both ment (convection) and prevents water vapor in compliance software components in advance using R-13 or R-19 Fiberglass Batt Insulation builders and buyers of homes the air from entering the wall. In a 100-square- C ONTROL MOISTURE IN WALLS package, can be ordered from batts and cover with a weatherproof barrier and commercial buildings Characteristics foot wall, one cup of water can diffuse through All climates require these steps: DOE by calling (½-inch drywall, plastic, or other sheet • Works with state and local drywall without a vapor barrier in a year, but 50 1-800-270-CODE Thickness R-value Cost • Install a polyethylene ground cover on or downloaded directly material). regulatory groups to improve (inches)(¢/sq.ft.) cups can enter through a ½-inch, round hole. the earth floor of houses with crawl from the Web at 7. Select insulation levels based on the MEC 3½ 11 12-16 building codes, appliance stan- In fact, sealing air leaks is 10 to 100 times as www.energycodes.org/ 5 spaces and slope the ground away from and the DOE Insulation Fact Sheet. 3 /8 13 15-20 dards, and guidelines for effi- important as installing a vapor barrier. resid/resid.htm. 3½ 15 (high density) 34-40 cient energy use the foundations of all houses. 8. Face-staple batts because side stapling 6 to 6¼ 19 27-34 MOISTURE CONTROL • Install a continuous vapor barrier that has a NOTICE: Neither the United creates channels for air flow and compresses 5¼ 21 (high density)33-39 • Provides support and grants States government nor any to states and communities Air sealing and moisture control make insulation Perm rating of less than one (see page 3). the insulation, thus reducing the R-value. If 8 to 8½ 25 37-45 agency thereof, nor any of their 8 30 (high density) 45-49 for deployment of energy- more effective. It is a myth that installing vapor employees, makes any warranty, face stapling is not an option, use unfaced • Place a termite shield, sill gaskets, or 9½ 30 (standard)39-43 express or implied, or assumes efficient technologies and barriers is the most important step for control- other vapor-impermeable membrane on batts or carefully side staple within ¼ inch 12 38 55-60 any legal liability or responsibility practices ling moisture in walls. Vapor barriers only retard of the stud face. This chart is for comparison only. Determine actual the top of the foundation wall. This for the accuracy, completeness, moisture due to diffusion, while most moisture or usefulness of any information, thickness, R-value, and cost from manufacturer or local action will prevent moisture from wicking apparatus, product, or process building supply. enters walls either through fluid capillary action into the framed wall from the concrete disclosed. The views and opin or as water vapor through air leaks. foundation wall by capillary action. ions of authors expressed herein do not necessarily state or reflect Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 20% postconsumer waste. those of the United States gov OFFICE OF BUILDING TECHNOLOGY, STATE AND COMMUNITY PROGRAMS October 2000 DOE/GO-102000-0772 ernment or any agency thereof. ENERGY EFFICIENCY AND RENEWABLE ENERGY • U.S. DEPARTMENT OF ENERGY

Wall DOE 772 MS.p65 1 10/30/00, 11:10 AM