Best Practices for Air Sealing Your Home

Air sealing the leaks around your house keeps your home more comfortable in Portland’s chilly winters and warm summers, and protects your indoor air quality. Learn your options for blocking leaks so you can achieve the best results possible.

Caulk

Caulk is a viscous substance that hardens after application. It’s typically sold in tubes designed to be loaded into a caulk gun. Caulk is used for air sealing gaps and cracks around non-movable surfaces, such as door and window frames, ventilation and appliance vents, points where pipes and wires penetrate exterior walls, and where the foundation meets the wooden sill on the home’s exterior.

All-purpose acrylic latex caulk is a good option for most interior sealing jobs. If you need to seal leaks in a wet area, such as the bathroom or kitchen, waterproof silicone caulk is a better choice. For outdoor sealing jobs, consider elastomeric or butyl caulk. Before buying caulk, check the product’s label to learn where it can be used.

Spray Foam

Polyurethane expanding spray foam insulation, sold in spray cans, is used to seal gaps between one-quarter inch and 3 inches wide around non-movable surfaces. It’s often applied around furnace flues, pipes, and other large penetrations in the attic and basement. In the crawl space, it can be used to seal a plastic vapor barrier to rigid foam insulation on the wall.

Because spray foam isn’t eco-friendly and is difficult to remove when repairs are needed, consider an alternative such as cellulose or cotton insulation.

Weatherstripping

Weatherstripping consists of strips of material used to block leaks on movable surfaces. The ideal weatherstripping depends on the surface you want to seal. Foam tape provides an inexpensive way to seal window sash tops and bottoms, as well as the insides of doorframes. For double-hung or sliding windows, use V-strip weatherstripping. Tubular gaskets, available in vinyl, rubber, and silicone, can be applied to window sash tops and bottoms and along doorjambs.

For more guidance on air sealing or to hire a pro for the job, contact us at Roth Heating & Cooling in the Portland area.