Regular ceilings are likely to be under attics with either batt insulation between the joist bays or in some cases rigid insulation between the rafters.
Insulating cathedral ceiling with foam board.
I m in the early stages of building an amazing workshop to showcase tools over at tool box buzz and shop projects here at hci.
The new workshop will be located over my garage in an area that was framed using attic trusses when we built the new house.
Foil faced iso board can be cost effective insulation for finished attics and cathedral ceilings.
Solve moisture and rot problems in insulated cathedral ceilings with closed cell foam ceiling insulation.
Rigid boards are manufactured from either.
A less expensive alternative is the more traditional vented cathedral ceiling insulated with fiberglass cellulose or open cell foam.
Attic trusses typically have a sloping ceiling.
Spray foam is a very expensive option however.
Insulating cathedral ceilings can be quite challenging.
Foam board insulation would be a more economical especially if you are supplying the labor see photo.
This is best for simple cathedral ceilings that are easy to ventilate.
If you decided to use a rigid foam board to help insulate your cathedral ceiling you would install the board on top of the roof sheathing and underneath the plywood at the top of the roof.
These should have straightforward framing with no skylights and with direct access to soffit and ridge vents.
Rigid foam board installation in the case of a cathedral ceiling involves installing three different layers that are each 1 5 inches thick according to the procedure discussed in this article appearing in fine homebuilding.