air sealing products

Air sealing products involve caulks and foams, but also weather-stripping materials and air barriers (plywood, drywall, rigid foams, housewraps). These different materials respond to different temperatures, different degrees of pressure and friction or to weather exposure...

Caulks

Caulks are the air sealing products for small gaps and joints (say, less than 1/4'' / 5 mm wide). Caulks vary a lot in their quality and in their properties and grades - exterior/interior, fire-resistant, high-temp... - which makes their choice less easy than one may wonder.

The fact that quality varies a lot within the same brand and between brands, also makes the choice trickier.

See, for details: Caulking Products and Caulking Tips

Weatherstripping sealing materials

Gaps in the movable parts of windows or doors demand specific air-sealing materials: weatherstripping products, namely, V-strip seals, gaskets, door bottoms, thresholds, sweeps, etc. See: Weatherstripping products basics

Foams

Expanding foams are a better choice than caulks when the holes and gaps are larger than, say, 1/4 inch (5 mm) and smaller than 3 inches (60 mm) wide. They are excellent to seal the openings around electrical wires or vent pipes. See: Sealing Foams

Rigid Air sealing materials

Plywood, drywall, housewraps and rigid foam insulation materials can be used for surfaces and very large unsealed penetrations. These materials are the core of the continuous air barrier that wood and steel frame homes should have over their whole envelope (exterior walls, ceiling, foundation...). These materials can also be used to air seal large holes, cracks and cavities.

See: Air barriers vs. Vapor Barriers