Insulate Under Bay Window Floor

In this article i ll share a detail for new construction and also a detail for renovating existing bay window.

Insulate under bay window floor.

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. To be used under bay window. This high performance thermal insulation board has 50mm of pir insulation. Bay windows are one of the more complicated window styles to install but their impact is well worth the effort.

I have removed the plaster and lathe but now i have a question. 50 mm celotex bonded to plaster board. I am planning on insulating my 1st floor bay window using celotex or similar between the joints. No vapour barrier is required and the foam blocks a considerable amount of sound transmission from the outdoors too.

Most people only insulate under the bay window. Buy this item from amazon uk. In addition to floors other cantilevered architectural features may require insulation. This type of window protrudes from the house while also letting in lots of light.

Side walls also need insulating if no cavity exists. The void between the joints drops down below the floorboard level and seems to be a void until just above the ground floor window. Celotex pl4050 is a thermal insulated plaster board. The smooth surface between the floor joists is cardboard laying loose on top of the t g flooring.

And the farther a bay window protrudes from the house the more dramatic the effect and the more it opens a room. Either way filling the floor cavity with spray foam delivers excellent thermal insulation while also keeping drafts out of your bay window area. If the floor is over a garage and has not already been insulated however it is recommended that each joist bay be filled with insulation. Also added 2 pics under the bay window showing the white vinyl siding 1 8 green foam sheet insulation brown lap siding heavily weathered white trim board and 1 2 white styrofoam.