How to fix a leak under a window?

stereomike · 10-28-2008, 02:01 PM

I pulled off the window casing under a window to discover water coming in when it rains, I've attached a picture of my problem.

There is caulking on the outside, but when it stops raining I will cut that away and re caulk, should I also caulk on the inside? Anything else I can do?

Marvin Gardens · 10-28-2008, 03:17 PM

First of all don't recaulk.

Find the leak. It could be above the window.

I suggest that you wait till it stops raining. Then take a hose and run it on slow. Go SLOWLY up one side of the window till it leaks. If it doesn't leak then go up the other side. If none of that leaks then go over the top.

Once you find the leak then deal with that.

I fixed a leak for a guy who had replaced the window after recaulking many times. He finally called me and I found that his leak was at the gutter where is was blocked and overflowing behind the siding.

buletbob · 10-28-2008, 04:34 PM

Agreed. Find the leak. could you post an outside window picture.

concretemasonry · 10-28-2008, 05:32 PM

One word of caution.

Even if you find a leak from the side, do not automatically write off the top as the real leak. - The same person probably installed the flashing above and on the sides and may have sealed the bottom too well. It is estimated that over 2/3 of the windows are not installed improperly. The common problem is lack of a moisture barrier and poor flashing practices.

Dick