Caulking to Prevent Water Leaks
Often water leaks at a window result from a breakdown in the connection between the frame of the window and the frame of the house. To prevent leaks, the window should be caulked where its frame meets the exterior siding. If the window is surrounded by wood trim, all gaps between the trim and the siding (and the trim and the window frame) should be sealed with a high-grade polyurethane caulk. Take special care to seal the top side of the top piece of trim. Puddling water at this location causes many window leaks.
Stopping Air Leaks
A window that leaks air can also mean excessive energy loss — and cost. Summer or winter, you don’t want your house to leak air, especially if you spend your hard earned dollars warming or cooling it.
Test a window for leaks by holding a lighted candle near all its joints and connections. If the candle flickers, you have an air leak. Check
- Where one section of the window meets another
- Where the windows meet the frame
- Where the frame meets the wall
You seal air leaks in the same way that you seal water leaks — by caulking exterior leaks and replacing weather stripping. Also, foam sealant can be injected between the frame of the window and the frame of the house. This is a major deterrent to air infiltration and also prevents water from leaking into the house.
Preventing Condensation on Glass, Frames and Sills
Condensation around windows can result when a window leaks air. Cold outside air mixes with warm inside air and creates a wet layer of condensation over the entire window. Condensation can actually form enough moisture to cause wood to rot. And don’t forget mildew. Condensation is basically a feed bag for mildew. Condensation can be reduced by:
- Sealing air leaks
- Replacing single-pane glass with double-pane “insulated” glass
- Using wood frame windows
- Using storm windows
If you have insulated windows and you see rainbows or condensation between the two sheets of glass, then your window has failed and should be replaced. The frame can remain, but the glass must be replaced. Here it is important to shop for the best guarantee. Where there are many who are ready to “sell to you” to get their piece of the almighty buck, there are a few who do offer a lifetime warranty. Study this aspect of your purchase carefully. A failed insulated window is expensive to replace at $150 and up.