Get a quick review of the most common sealants — plus a few uncommon options — for sealing up holes big and small.
Thermal Bypass Checklist package (50+ details).
From painter’s caulk to leftover drywall, you can arm yourself to battle air leaks with many items you may already own
When air-sealing an attic, you’re going to need a whole array of different products, both for caulking and sealing as well as for blocking off big air leaks. Here’s what I use. Good-quality caulking can be something like a painter’s caulk, as long as it stays pliable over time. Another is fire-blocking caulk. This is fire-resistant and used around masonry, fireplaces and hot exhaust pipes from heating appliances. Spray foam is good for filling medium to large gaps. This is a professional-style gun. You can also use some of the single-use cans that you find at a home center. You’ll need tapes for sealing joints in hard products like drywall and rigid foam — housewrap tape or aluminum-faced acrylic tape. Going up against masonry fireplaces, or filling gaps anyplace that is hot, you’re going to need pieces of metal—even recycled drip edge, like I have here. Working in an attic, you’re going to be dealing with dust, so a good-quality dust mask is useful. To fill big holes in rigid products, like a soffit that goes up into an attic, I used rigid foam panels. They give you insulation and also block the air. Even leftover pieces of drywall or plywood or OSB will work as well. One product you don’t see too much in residential construction is acoustical sealant. It usually comes in large tubes and is not very expensive. It works really well because it doesn’t really harden over time; it just skims over and remains very pliable. Whatever it sticks to, it maintains its seal over the long term. Whenever you’re working with these sticky products, you’re going to want to wear rubber gloves so that you don’t get all crudded up and spend hours cleaning yourself.