ER Project House: Window Sealing

Since getting the results of the DIY home pressure test, I’ve identified a couple areas that need work on the house. The first thing on the list is to take a look at the windows on the second story of the house. They are older single pane windows that are still in decent condition. However, they are pretty leaky.

The first step was to take care of the gaping holes above each window. Some of them measured over 1/4 inch. With the hollow walls I have, this leads to huge amounts of air infiltration. So, I used a mixture of caulk and expanding foam to fill the cracks depending on the width. I used expanding foam for the larger gaps and caulk for the smaller ones.

The next step was to make sure that air wasn’t just going to get around the newly laid caulk and leak out the other side of the boards. This required more caulk around the trim boards.

Now that the leaking around the window trim was taken care of, it was time to look at the window sealing against the sill plate. This was a very easy fix with some stick on weather stripping.

There are two important things to make sure of when you are installing weather stripping. First, make sure you cut the weather stripping to the full length of the bottom of the window. The weather stripping will now hold the window up higher, and if the weather stripping does not extend the full length of the window, you will have created a gap for air to leak through. Also, make sure to put weather stripping on the top and the bottom window on double hung windows. Both of the windows have to seal against the sill plates.