Insulate Below Bay Window

How to seal a leaky bay window.

Insulate below bay window.

I am thinking of putting 4 thick foam insulation under it cover that with plywood and finishing off with trim boards around the bottom to hide it. This is a great example of how to insulate a bay window. I want to insulate the bottom of this bay window after i repair the sill. The rim joist under the window appears to have only the 1 8 green foam vinyl and lap siding covering it no other insulation.

Quite often the insulation in this area is dealt with long after the framing is finished and results in a very cold drafty spot in the house. And the farther a bay window protrudes from the house the more dramatic the effect and the more it opens a room. Bay windows are one of the more complicated window styles to install but their impact is well worth the effort. I recently found the styrofoam under the bay was only press fit in some areas no fasteners held up by a friction fit on the back side of the lap siding.

The sketch above shows one method for insulating the deck overhang at a bay window or cantilever that encloses a bump out. This type of window protrudes from the house while also letting in lots of light. Because it is difficult to properly insulate and air seal these areas without filling the cavity getting sufficient heated air in to warm these areas during the winter months can be tricky. New construction bay window floor overhang insulation detail.

No vapour barrier is required and the foam blocks a considerable amount of sound transmission from the outdoors too. Either way filling the floor cavity with spray foam delivers excellent thermal insulation while also keeping drafts out of your bay window area. The panes of glass used to create such windows as. A bay window juts out and away from the house usually in a semicircular form much like an observatory window.

Never having done this i want to make sure what i plan to do makes sense and there are no gotchas.