There are a number of reasons you may have leaky windows in your home, including poor installation work and worn parts such as bad glass seals or broken window sealants or weather stripping. Whatever the cause of your leaky windows, it's essential that you find a solution as soon as possible because leaky windows can promote the growth of mould and mildew, cause rotting (if you have wooden framing), and they can even compromise your home's energy efficiency through air leaks. While it's usually recommended that you leave glass window repairs to a professional, especially for relatively extensive damage, you can always take care of a few window problems such as leaks on your own. However, you need to do it right, and here is a guide to help you.

Fill All Gaps

Leaks are usually caused by gaps on your windows. Therefore, the first step to fixing your leaky windows is taking your time to do a thorough inspection for any gaps. You will then have to caulk as well as seal cracked caulking or damaged/loose weather stripping. However, you will have to get rid of the old caulking first. That's because if you don't clean off the area well, the new caulk or stripping won't adhere perfectly and could easily peel away and call for repairs again. A putty knife will come in handy here, but you can also use other tools such as a stiff brush or a screwdriver. Keep in mind, however, that removing old caulking can be quite challenging, and you may have to put in a little more effort. If the old caulk is proving quite tough to remove, you can apply some petroleum jelly to loosen things up.

Once the old caulk is off, you may want to wash the area with some water, but remember to let it dry so that you don't seal in moisture with the new caulk. Applying the new caulk is simple. You have to cut off the tip of the cartridge and insert it into the dispenser, sometimes referred to as the gun. To release the caulk, all you have to do is press the trigger, laying a continuous bead (to avoid bubbles and voids) in the joints between the window and the frame. The caulk should cure overnight, after which you can paint it.

Fix the Frame

The window framing itself can also be the cause of the leak. You will have to inspect it carefully to locate the leak. One easy way to do this is to have someone spray or pour some water on a section of the window while you watch for any leaks from the inside. If there are gaps between the window and the frame, caulking should do the trick. If part of the frame is rotten, use your putty knife to chip it out, then fill the resulting void with an epoxy wood filler.