Comprehensive Attic Package - Vented Attic
Description
Installed correctly, comprehensive vented attic upgrades can significantly reduce utility costs while improving comfort, indoor air quality, and durability of the attic structure.
Checklist
This U.S. Department of Energy checklist includes important specifications that can contribute to a complete and quality installation. All work shall comply with these specifications, all relevant codes and standards, and all manufacturer installation instructions. The contractor shall check each box on the checklist below and sign and date at the bottom to certify the work is completed.
| ▢ | P.1: The attic shall be inspected for water leaks and moisture, structural, or pest damage. A list of all needed repairs shall be provided to the homeowner before attic work begins so remediation can be fully addressed as necessary. |
| ▢ | P.2: If there is active knob and tube wiring present in the attic, the homeowner shall be directed to hire a licensed electrician to inspect the wiring and provide a list of any necessary repairs to the homeowner. The work shall not begin until the homeowner provides written notice that all necessary repairs in the attic are completed. |
| ▢ | P.3: The attic shall be inspected for the presence of any existing HVAC duct or vermiculite attic insulation that may contain asbestos. If asbestos is present, work will stop and the material will be safely removed according to EPA requirements and guidelines. |
| ▢ | P.4: A combustion safety test is recommended to be performed if any natural draft combustion equipment exists in the home to ensure there is no backdrafting or spillage. If performed, any combustion safety issues not addressed by installation measures included in this checklist shall be addressed before proceeding with the installation. |
| ▢ | P.5: All exhaust fan ductwork in the attic shall be inspected for proper installation including no excessive length and sagging, no kinks, and termination to outdoors (i.e., exhaust fans shall not vent directly into the attic). Required modifications shall be identified and included in this scope of work. |
| ▢ | P.6: The contractor shall remove or set aside existing insulation as required for installing air sealing, air barriers, and insulation. |
| ▢ | P.7: Debris shall be removed from existing attic ventilation openings (e.g., ridge, gable, and soffi t vents). |
| ▢ | P.8: The existing net free attic ventilation area shall be determined, and the contractor shall choose between Attic Ventilation Area Option 1 (requiring 1/300 of attic area, high and low openings, preferred) or Option 2 (requiring 1/150 of attic area, only high OR low openings, less preferred). |
| ▢ | P.9: The contractor shall verify that new attic insulation will not block attic ventilation openings and shall plan to modify attic ventilation openings as required for adequate clearance, for example by installing baffles. Where one or more openings need to be relocated, the existing opening(s) shall be closed off with solid sheathing or other weather-resistant material and sealed and patched to match the existing finishes (e.g., exterior roofing, siding, or soffit). |
| ▢ | P.10: Any heating and cooling and exhaust ducts located in the attic shall be inspected. Any separated or disconnected ductwork other than dryer ducts shall be secured with mechanical fasteners (e.g., screws and clamps). Damaged ducts “compressed duct” restricting air flow or with visual leaks shall be repaired or replaced. Flexible ducts with excessive length shall be cut to proper length to ensure maximum sag is ½ inch per foot. Sharp bends shall be corrected so bends are greater than or equal to one duct diameter radius. All accessible unsealed seams in ductwork shall be sealed with UL-approved mastic, UL 181 tape, or equivalent. |
| ▢ | P.11: All unsupported horizontal heating and cooling duct runs shall be supported with hanger strap or saddle supports that are at least 1.5 inches wide and spaced no more than 4 feet apart, in accordance with the Air Conditioning Contractors of America (ACCA) Manual D and manufacturer’s recommendations. Additional supports shall be provided before and after sharp bends in the ductwork. The maximum permissible sag between supports shall be ½ inch per foot. |
| ▢ | I.1: All gaps, cracks, seams, and penetrations between conditioned and unconditioned space (such as gaps in the attic floor and attic knee walls around lighting fixtures, HVAC duct boots, electric wiring, plumbing pipes) shall be sealed with sealants if the gaps are narrow enough to meet manufacturer instructions (e.g., caulk, foam, aerosol sealant). If gaps are too large for sealants, rigid blocking material shall be used to fill the gap and shall be sealed in place with sealants per the sealant manufacturer’s instructions. Fibrous insulation is not an air barrier and shall not be used for air sealing. |
| ▢ | I.2: The seams where drywall attaches to the top plate at all interior and exterior walls shall be sealed from the attic side with a caulk, spray foam, or spray-applied sealant. |
| ▢ | I.3: Large gaps and openings between the attic and conditioned space below (e.g., dropped soffi ts with open framing, knee walls without attic-side solid backing, or balloon-framed gable walls without blocking) shall be closed off using a solid material such as rigid foam or OSB that is sealed at the edges and seams with caulk, sealant, or mastic. |
| ▢ | I.4: Gaps around masonry chimneys, flues, or combustion appliance vents shall be sealed with sheet metal and high-temperature rated caulk or foam. Insulation dams shall be constructed around chimneys, flues, and combustion appliance vents as needed with combustion clearances using heat-safe materials in accordance with local building code requirements. A masonry chimney typically requires a 2-inch clearance to combustibles; Type-B (double wall) gas vent pipe typically requires 1-inch clearance to combustibles; the air barrier may be metal that is air sealed using high-temperature-rated caulk; cellulose and fiberglass insulation are considered combustible; local building code may allow mineral wool to contact a masonry chimney but not a metal gas vent. |
| ▢ | I.5: Attic access panels, doors, and drop-down stairs shall be insulated with a minimum of R-10 insulation and gasketed at all edges (not caulked) to provide a continuous air seal when closed. In the case of drop-down stairs, this may require a box made of rigid insulation or other similar options that is sealed at all seams with a sealant such as caulk, mastic, or tape, which is then set on the attic side of the opening. |
| ▢ | I.6: All non-ICAT (Insulation Contact Air Tight) recessed light fixtures shall be boxed with a solid material such as drywall or rigid foam that is sealed at all seams with a sealant such as caulk, mastic, or spray foam and provides clearance from the fi xture as required by the local building department. |
| ▢ | I.7: Before installing fibrous attic floor insulation, wind baffles or blocking shall be installed at all attic eaves adjoining vented soffits to prevent air flow through the edge of the insulation. A minimum of 1 inch clear air fl ow path shall be provided for ventilation air to flow from the soffit vents to the attic space extending at least 6 inches above the height of the attic insulation. |
| ▢ | I.8: All accessible HVAC and exhaust fan duct leaks, connections, and plenums shall be sealed with UL-approved mastic, UL 181 tape, or equivalent (e.g., aerosol sealant) applied in strict accordance with manufacturer’s instructions. |
| ▢ | I.9: If the air filter is installed in a filter box attached to an air handler located in the attic, the filter access panel shall be fitted with an air-tight gasket and a MERV 8 or higher filter shall be installed in the filter rack. |
| ▢ | I.10: Duct boots located in the attic-ceiling interface shall be sealed to finished surfaces with caulk, spray foam, or other approved sealants. |
| ▢ | I.11: All accessible HVAC ducts in the attic shall be insulated to ≥ R-8 for supply ducts and ≥ R-6 for return ducts or to local code. |
| ▢ | I.12: Insulation moved during duct sealing and insulating shall be replenished to levels that meet or exceed local building code requirements. |
| ▢ | I.13: Exhaust fan ductwork shall be modified as required for the most direct route to the outdoors, with as few bends as possible. To reduce noise, no bends occur in the first three feet from the fan housing. |
| ▢ | I.14: The exhaust duct outlet vent shall be located on the exterior of the home at least 10 feet from any air inlet and where it does not direct air flow onto a walkway. If the exhaust duct outlet needs to be relocated to meet these requirements, the existing opening shall be closed off with solid sheathing or other weather-resistant material and be sealed and patched to match existing finishes (e.g., exterior roofing, siding, or soffit). |
| ▢ | I.15: All exhaust duct seams and connections shall be sealed with UL-approved mastic, UL 181 tape, or equivalent. |
| ▢ | I.16: In cold climates, all accessible exhaust ducts in the attic should to be insulated to ≥ R-8 to reduce risk of condensation. |
| ▢ | I.17: Where the exhaust fan terminates with a wall cap, verify the presence of a damper that closes when the fan is not operating. If there is none, a damper shall be installed per local code requirements. |
| ▢ | I.18: The minimum net free attic ventilation area shall be 1/300 of the attic area. Existing attic ventilation openings shall count towards this area and new attic ventilation openings shall be installed as required per local building code requirements. The minimum net free attic ventilation area may be based on the attic area as follows: 1.5 ft2 for up to 500 ft², 3 ft2 for 501 to 1,000 ft², 5 ft2 for 1,001 to 1,500ft², 7 ft2 for 1,501 to 2,000 ft², and 8 ft² for over 2,000 ft². |
| ▢ | I.19: At least 40% of the net free attic ventilation area shall be located within 3 feet of the ridge or highest point of the attic. The remaining net free attic ventilation area shall be located in the bottom third of the attic space. |
| ▢ | I.20: The minimum net free attic ventilation area shall be 1/150 of the attic area. This option is used when balanced (high and low) ventilation openings are not possible or practical. Existing attic ventilation openings shall count towards this area and new attic ventilation openings shall be installed as required per local building code requirements. The minimum net free attic ventilation area may be based on the attic area as follows: 3 ft² for up to 500 ft², 6 ft² for 501 to 1,000 ft², 10 ft² for 1,001 to 1,500 ft², 14 ft² for 1,501 to 2,000 ft², and 16 ft2 for over 2,000 ft². |
| ▢ | I.21: Insulation shall not block the free fl ow of air through attic ventilation openings. |
| ▢ | I.22: Attic ventilation openings shall be between 1/16 to 1/4-inch, open directly to the outdoors, and be protected from rodents, birds, etc. Attic ventilation openings greater than 1/4-inch shall be covered by material with openings between 1/16 to 1/4-inch, which meets all local building code requirements. |
| ▢ | I.23: Greater than R-19 or local code insulation shall be installed with an attic-side air barrier at attic knee walls, skylight shaft walls, vertical portions of all dropped ceilings, and any other vertical wall adjoining the conditioned space. All seams and gaps in the air barrier shall be fully sealed. |
| ▢ | I.24: If a kneewall exists in the attic separating conditioned space from unconditioned space, verify that cavities between the floor joists beneath the kneewall are sealed with air barrier materials. |
| ▢ | I.25: Attic insulation that meets or exceeds prescriptive requirements in local code shall be installed at all flat and sloped surfaces adjoining the conditioned space with less than 2% gaps, voids, and compressions. |
| ▢ | I.26: All attic insulations shall be uniform and shall conform to manufacturer-specified density. Fibrous insulation installation shall include attic rulers to verify full depth. |
| ▢ | C.1: The home shall be inspected for the presence of a whole-house ventilation system. If one is present, the actual air flow shall be tested and verified to meet a target ventilation rate based on house size as follows: 50 cfm for up to 1,500 ft2, 70 cfm for 1,501 to 2,500 ft2, and 100 cfm for over 2,500 ft2 . If the home has no whole-house ventilation system, or if the existing system does not meet the target ventilation rate, recommendations shall be made to the homeowner to either install a new system or repair the existing system to meet the target ventilation rate. |
| ▢ | C.2: If an exhaust vent was installed in a wall, the wall cap damper shall be checked to ensure it is operating correctly. |
| ▢ | C.3: In EPA Radon Zone 1, a radon test kit shall be provided to the homeowner at the completion of the work with a recommendation to initiate a radon remediation strategy if post-retrofit radon measurements exceed EPA acceptable levels. (See https://www.epa.gov/radon.) |
| ▢ | C.4: After completion, a combustion safety test shall be performed if any natural draft combustion equipment exists in the home to ensure there is no backdrafting or spillage. After attic air sealing, a natural draft furnace or water heater located in the home may no longer have sufficient combustion air. Recommendations shall be made to the homeowner to install direct-vent equipment at time of replacement for any natural draft combustion equipment. |
Comprehensive Attic Package - Vented Attic Background
Tips to Sell Quality Installed Home Improvements
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