9 products to caulk, seal your way to summer comfort
Homeowners looking for energy savings often focus on big-ticket items like newer water heaters and furnaces. Those items certainly can be important upgrades, but simply eliminating air leaks can provide significant benefits at a surprisingly low cost.
In the summer our cool interiors are like sponges for outside heat, and every small gap in a house’s thermal envelope is a pathway for warm air to come in.
The warmest air in your house will always look for a way up, and if it finds a path to escape, more outside air will be pulled into the house to replace it. This is called the “stack effect.” You should check the insulation between the attic and living space, and anywhere any vents, chimneys or flues exit the roof.
Caulking, sealing and weather-stripping are the best low-cost ways to stop air infiltration. The difference between caulk and sealants is simple—elasticity. Elasticity is especially important for exterior applications, so look for products suitable for your particular project.
Here are nine related products we believe are worth your consideration.
Most common air leaks: windows and exterior doors
Windows and exterior doors are the most common air leaks. Applied from the outside, acrylic latex caulks with silicone don’t just fill a gap such as between the window and the siding, but repel moisture as well and adhere to a variety of surfaces. Synthetic rubber caulks are fairly new, but get high marks for their ability to expand and contract with temperature swings. They are paintable, and can be applied to wet or dry surfaces.
Doors and moveable window panes obviously can’t be sealed shut, so door sweeps, V-strips, felt strips and foam tapes compress, expand or simply get in the way to prevent warm air from entering. If your exterior door has an adjustable threshold raise it until it noticeably scrapes across the threshold ... then back it off. A rule of thumb is to put a piece of paper in the gap...when you pull the paper out you should feel a bit of resistance. Double-hung windows should get a bit of weatherstripping where the sashes meet.
Fireplace dampers, attic hatches, wall or window-mounted air conditioner units and where utilities enter the home all need to be checked as well. Any air leaks will contribute to higher cooling bills.
The big gaps
What if an exterior gap is too large to fill with ordinary sealants or caulks? Where your hose bib enters the house is a good example, similar to the chimney or flue. Another is your dryer vent. Expandable polyurethane foams are perfect for these areas. They may expand a bit more than you anticipate, but don’t worry, just try a squirt on a piece of cardboard first! Once applied, any excess can be removed with acetone (like nail polish remover, but available in home centers in larger packages) before it cures or be cut away, sanded or scraped off afterward.
Let's go indoors
Exterior walls are obviously most important, but don’t forget the stack effect. Interior walls are not insulated, so even the small gap around an outlet or a light fixture lets air into the framing where other holes for plumbing, wiring, etc. connect spaces allowing warmer air to find its way up and eventually out. Sealing electrical outlets, switches and wall or ceiling lighting fixtures should be included in your fight against air infiltration. Note: It’s important to observe any code restrictions and safety concerns. In case of fire, electrical components sealed with an intumescent fire-blocking foam can prevent the stack effect from hastening the spread of fire. Other foams are fine for simply blocking airflow, but will quickly burn away in a fire.
When sealing gaps in the kitchen or bathroom, look for moisture-resistant products even if the biggest worry is condensation.
Finally, remove and replace any dried out or cracked old caulk and sealants. If they’re that old you can probably find a newer, more efficient product anyway.
Jeffrey Campbell is new products editor for ProudGreenHome.com. Look for his recurring columns highlighting tools and media regarding sustainability.