Attic Insulation & Air Sealing in Decatur, AL

Attic insulation and air sealing in Decatur are mostly a summer project. On a sunny July day the attic above a shingle roof gets far hotter than the outdoors, and every gap in the ceiling below lets that heat into the house. Insulation slows heat moving through the ceiling. Air sealing stops hot air from leaking straight through it. You need both, and the order matters: seal first, then insulate, because loose insulation laid over open gaps does far less than people expect.

How much insulation

Alabama's amended energy code calls for R-30 in ceilings in Climate Zone 3. For an attic with no insulation, ENERGY STAR recommends R-49 in Zone 3, and for one that already has 3 to 4 inches it recommends adding R-38. Many Decatur homes from the 1960s and 1970s, which make up roughly 37% of the city's housing in Point2Homes' census summary, started with less than half of today's target and have lost more to settling and foot traffic since.

Where attic air leaks

The biggest gaps are usually in the same spots: the attic hatch or pull-down stairs, recessed lights, bath fans, the plumbing vent stack, wiring holes in the top plates of walls, the chase around the furnace flue, and dropped soffits over kitchen cabinets. Those get sealed with foam, caulk or rigid board depending on the gap. In homes with the air handler in the attic, the duct connections and the return plenum are often the worst leaks of all, and sealing them is part of the job.

Blown-in, batts or foam

For most open attic floors, blown-in cellulose or fiberglass over a sealed ceiling is the most cost-effective way to reach R-38 to R-49. It fills around wiring and framing and goes in fast. Spray foam fits better where the floor cannot be reached, where there is a bonus room or kneewall, or where the plan is to seal the whole attic by spraying the roof deck. HomeGuide prices foam on the attic floor at $1,100 to $6,800 and foam on the roof deck at $1,500 to $9,000, compared with an average attic insulation job of about $1,800.

Ventilation stays in the plan

A vented attic still needs air to move from the soffits to the ridge or roof vents. We install baffles at the eaves so new insulation does not block the soffit vents, and we keep insulation away from flues and recessed lights that are not rated for contact. If the bath fans dump into the attic, we point that out, since that warm, wet air belongs outside.

Rebates

TVA's EnergyRight program lists a $300 rebate for attic insulation and another for envelope air sealing, done through its Quality Contractor Network. Check the current terms before the job.

Tell us which rooms feel hot or what the power bill has been doing, and we will measure the attic and send a written quote. Get a free estimate