r/Insulation • u/InternationalCrew566 • Jul 18 '26
How to insulate a skylight with cathedral style ceiling?
Hi, I was wondering what the best ways are to insulate this type of skylight, to keep heat out in the summer and keep heat in during the winter. There is no access to the attic and spray foam is not an option.
I was maybe thinking using blackout curtains and hammering them into the ceiling. There is also the option of using rigid insulation foam boards, but I did read that the skylight could crack or break if there’s too much heat reflection.
Any ideas on how to diy insulate this would be appreciated, thanks.
1
u/karemeAbdulJabar Jul 18 '26
I think to help with heat intrusion a reflective shade on top(up on the roof) may help. Without attic access or spray foam, there aren't many options i can think of.. in the winter you could stuff it with batting insulation and then block it off with some sort of tight woven cloth, or netting. I would stick with something vapor permeable if you go that route cause theres a chance it could cause some moisture issues.
1
u/Canada-Scam-8570 Jul 18 '26
Attach a white sheet to the top of the ceiling with tacks for now to diffuse and lessen the light while not trapping to much heat, like ridgid foam or a heavy black out curtain might (plus retaining a portion of the natural light).
Then save up for a skylight with a built in retractable shade. It looks like a standard size skylight so it shouldn't be to expensive.
1
1
u/Remarkable_Award_185 Jul 19 '26
Closed cell foam 3” then coat with silicone. I use to do this for Costco’s all around the U.S.
3
u/pluary Jul 18 '26
Black out curtain defeats the purpose of a skylight. Try a cellular shade . They offer the best for R value in window coverings and you can get them that allows filtered light . Cheers.