Leaking Window Causes and Repairs

Jiaqian AirplaneFan (CC BY 3.0) via Wikimedia Commons

When’s the best time to spot a leaking window? In the middle of a rainstorm, of course. When’s the worst time to fix a leaking window? Ditto. Don’t panic, though. Get out your phone and take a picture of the mess instead. That way, if you need to call a pro to take of your problem, you’ll have clear evidence as to the location and severity of the leak. And, as an informed consumer, do your homework by checking out these leaking window causes and cures.

1. Inspect the weep holes. Weep holes are openings built into the bottom of your metal or vinyl window frames, which are designed to drain off precipitation that collects in the window tracks. If your window is leaking because these holes have clogged up, breathe a sigh of relief. Clearing clogged weep holes is the simplest, lowest-cost fix for window leaks. Remove fallen leaves, twigs, insect corpses and other objects that may be blocking these openings. Then clean the holes out with a cotton swab or bit of wire (the slow way) or a spritz of compressed air (the shortcut). Clear weep holes are able do their job properly and won’t let the tracks overflow in heavy rain.

2. Look at your window seal. The glass of your window should be solidly sealed to a rubber or vinyl gasket within the frame. If the pane has loosened over the years, renew the seal, using transparent silicone caulk.

3. Check your window frame. If the frame is the cause of your leaking window, there are several possible repair scenarios, as follows:

  • Best-case scenario: You’ll find a gap in the caulk sealing the frame to the exterior wall, which is letting in drafts and possibly water as well. Apply some new, good-quality caulk for an easy and inexpensive repair. (TIPS: For proper adhesion, be sure to thoroughly remove any old flaking caulk and clean the window frame before you start. And take care you seal the top of the window -- where precipitation can puddle -- as well as the bottom and sides.)

  • Not-so-bad-case scenario: It could be that the existing weatherstripping has worn out. Take down the operable part of the window (the portion that slides horizontally or vertically when you open it) first. Then remove the old weatherstripping, along with any traces of leftover adhesive, and replace it with a new peel-and-stick version (available at most hardware and home stores).

  • Worst-case scenario: You may discover that your wooden window frames have rotted and you will need to hire a pro to replace them. Or you might find that the frames were incorrectly installed in the first place; actually not such a bad scenario if they are still under warranty and if the original installer is still in business and if he’s prepared to honor the warranty.

4. Consider other possible sources of leakage. Sometimes, water that appears to be the result of a leaking window is really coming from another source altogether. Make sure that the source of the leak is not actually your home’s roof, exterior walls, or upstairs bathroom.

5. Minimize water damage. If heavy rain makes window repair impossible for the time being (or if you’re waiting for a pro to arrive and fix the problem), meanwhile you can at least minimize water damage, which, unchecked, may lead to mold and rot. Place a rolled up towel or large rag in the area of the leak -- to absorb that darn water -- and change it regularly for a dry one. If at all possible, move carpeting, furniture, and other vulnerable possessions away from the window area.

Laura Firszt writes for networx.com. 

Get Free Quotes

Looking for a Pro? Call us at (866) 441-6648

Get Free Quotes
  • Service Needed
  • Zip Code
Get quotes from qualified local contractors