Use Gap and crack sealant on the window sill

draftsillwindows

I have a small gap (2mm) under the window sill that is causing some draft to come inside the house. I have attempted to correct this using the Ge Silicone Caulk, but the draft continues to come in.

So I am going to now try the gap and crack sealant in that area? The name of the product is Gaps and Cracks Insulating Foam Sealant and it is available at home depot.

How can I stop the draft from coming in? Is this the right product that I should use?

The temperature outside is 20 degrees F.

Best Answer

If you caulked it and there's still a leak, you didn't caulk the whole gap. Air isn't going to come through silicone caulk. For such a small gap, expanding foam is overkill and may do more harm than good if it expands too much and widens the gap, which could cause the window to start sticking.

Another possibility is that there are additional gaps and holes in the area. Windows--especially old ones--are notorious sources of air leaks. Caulk the heck out of every gap you can find. If the windows have wood trim, caulk that to the drywall and the windows using color-matched or clear caulk. If you really want to do a thorough job, you can temporarily remove the trim and seal the exposed area between the rough opening and the window with expanding foam--be sure to get the kind that Tester101 recommended for this--the low-expansion window & door foam--and then replace the trim. And if your windows are of the very old variety that have poor seals, add stick-on compressible foam gaskets to the sliding sashes that contact the frame. You'd be surprised how much that can help.