Air Seal Attic Joysts

Foam or caulk small gaps in your attic.

Air seal attic joysts.

While most of the air leaks in your attic are probably covered up by insulation you can detect these air leaks by looking for patches of dirty or dark insulation. The number one prep step. Move in a steady stroke around the joist. Two ways to air seal and insulate a rim joist rim joists are a common source of air leakage in basements and are often left uninsulated.

Seal all gaps and cracks around rim joists though you may not be able to see cracks in the rim joist cavities it is best to seal up the top and bottom of the inside of the cavity. This condensation can result in mildew and mold and potentially cause surrounding wood surfaces to rot and decay. Keep in mind that foam cures in just 30 60 seconds. Find a diagram of common air leaks here here s a quick primer on fixing draft prone spots.

Spf expands when it is applied forming a continuous air barrier that prevents air leaks. You can take a do it yourself approach but if you run into any of the following problems in your attic energy star recommends that you contact a. Gaps in the attic or between the lower floors and the attic will let heated or cooled air escape to the great unconditioned outdoors making any insulation you add essentially useless. Air sealing the attic is an important project but it can be challenging.

After sealing attic air leaks complete the job by sealing basement leaks to stop the chimney effect. Push down on the ejector to remove the nozzle once spraying is complete. Firmly reinsert nozzle for an airtight seal. Then finish up by sealing the access hatch with self sticking foam weatherstrip photos 10 and 11.

If builders would conscientiously air seal the attic ceiling after the drywall is hung before insulation getting to 3 ach50 would be much easier. This was a perfect opportunity to air seal. Sealing air leaks in the attic also minimizes humidity and moisture from condensation that can occur due to air intrusion. The first step toward an energy smart rim joist is to caulk gaps between the foundation wall and the mudsill the mudsill and the rim joist and the rim joist and the subfloor.

If your hatch rests directly on the moldings like ours did add 2 1 2 in wide stops around the. If you do seal air leaks around flues make sure that you use heat resistant caulk. With this being the case we suggest consulting a qualified healthy home expert to get it done. The dirt comes from dusty air leaking into your attic.

By sealing only the attic leaks we cut the air leakage rate from 4 460 cfm to 2 180 cfm more than half the total air leakage. For that space if all the insulation in there now is coming out and being totally replaced as part of the insulation job so the attic floor will be completely exposed anyway for roughly 3000sf of attic normal air sealing cost would probably be in the 250 400 range depending on whether your attic was used for ducting and wiring runs or not.