Air sealing on Long Island

Air sealing comes first

Insulation slows heat, but it doesn’t stop air. Gaps around pipes, wires, chimneys, lights and hatches let warm air escape all winter. Sealing them is the cheapest way to make a house more comfortable, and it lets the insulation work.

On Long Island, the biggest leaks are usually in the attic floor and around the rim joist. Attic leaks also cause ice dams in winter.

Where we seal

• Attic floor: around pipes, wires, lights, the chimney and the hatch.
• Knee walls: in capes, where side attics meet heated rooms.
• Basement: the rim joist and where pipes and wires come in.

How we find the leaks

A blower door test depressurizes the house so leaks show up. We test before and after where a program calls for it, so you can see the difference in numbers.

Rebates

On Long Island, gas is mostly National Grid and electric is PSEG Long Island. Depending on your home and what is funded this year, that can open National Grid, PSEG Long Island or NYSERDA programs. For 2027, Con Edison and National Grid plan one joint weatherization program for market-rate homes and apartment buildings. We check what is open for your address before we price the job. See the rebate guide.

Common questions

Will sealing make my house stuffy? We seal the leaks you don’t want, such as attic bypasses and rim joists. If a house gets very tight, we tell you whether it needs ventilation.

How long does it take? Most homes take a day, often together with attic insulation.