Insulate Under Bay Window

Bay windows are one of the more complicated window styles to install but their impact is well worth the effort.

Insulate under bay window.

To be used under bay window. No vapour barrier is required and the foam blocks a considerable amount of sound transmission from the outdoors too. This high performance thermal insulation board has 50mm of pir insulation. Bay window and floor deck cantilever insulation details.

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. Side walls also need insulating if no cavity exists. 50 mm celotex bonded to plaster board. The rim joist under the window appears to have only the 1 8 green foam vinyl and lap siding covering it no other insulation.

This type of window protrudes from the house while also letting in lots of light. The problem of having cool floors under bay or bow windows and alcoves is a very common one. I want to insulate outside under the bay but fiberglass insulation is too thick as i only have 1 1 2 between the bay ceiling to the bottom of the siding. Either way filling the floor cavity with spray foam delivers excellent thermal insulation while also keeping drafts out of your bay window area.

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. Outside under the bay is open. And the farther a bay window protrudes from the house the more dramatic the effect and the more it opens a room. I ve written quite a few articles on how to insulate basement walls and floors but one more specific topic related to this subject keeps coming up and that s how to insulate a bay window floor or cantilever floor framing.

I have a bay window in my kitchen facing south that gets very cold on the floor during the winter months. Buy this item from amazon uk.