We have removed our rough sawn cedar from our cathedral ceiling in our 80's home. We found fiberglass insulation and 2x6 joists (the roof is directly above). The first electrician came out before we removed the ceiling and assumed there was no insulation and said we needed to get spray insulation because of the condensation can lights can cause. The other electrician we called out came after we removed the ceiling and did not say anything about condensation. Neither said anything about ice dams. I am seeing all this pretty scary stuff when doing my research, and am thinking we shouldn't put in recessed lighting now! We live in Wyoming where the climate can be pretty cold, but is usually very dry.So, if we use LED lamps and IC airtight housings, will the heat transfer really be bad enough to cause condensation and/or ice dams? Would it help to put some foam board between the shallow housings and the roofing substrate (if it fits)? We are only planning on putting up 6 6" lights in a 10x20 room...
You have to get the right kind of lights. LED lights don't get all that hot, but unless they're made for zero clearance, yes they do need some airspace around them. They make some with no need for airspace around them. They have an additional can around them to allow the space they need. Get the right kind, no problems, get the wrong kind, lots of problems.
Lighting For Cathedral Ceiling
I highly recommend you beef up the structure of your ceiling rafters and that will solve multiple issues I see in this project. That will give you plenty of clearance for lighting fixtures and it will also allow for more insulation along with proper ventilation. If it were my ceiling I would sister a minimum of 2 x 10 lumber to the sides of the existing 2 x 6 rafters you now have. Those 2 x 6 rafters are way under size for heavy snow loads and the current space in no way allows for enough insulation. I have done this exact kind of thing in my home when I used excess attic space to build a large multipurpose room. I nailed and used construction adhesive to attach or sister beefy 2 x 10's to the sides of each of my existing roof rafters. Then I could properly insulate the ceiling of the new room along with making the structure much stronger. The extra thickness of the space won't be noticeable at all when the ceiling is put back in but you'll have a much safer and sturdier roof and ceiling. If you're doing this project with a building permit then what I've described above will be required by the building inspector for sure. You will have to meet the building code for the R value of the insulation etc etc. But, even if you're doing this without involving the building dept, it will be in your best interest to beef up the lumber and add the additional insulation anyway. It will be a very small additional cost to pay considering the savings you'll recoup in energy bill not to mention the overall safety factor. Do a search on sistering roof rafters and you can find a good bit of info online if what I've said doesn't make sense to you. If I can give you additional advice or help you find more info online please get in touch. Good luck and I hope this helps!
with that type of light they need to have free air around them ,you dont have enough space,nor would you roof be insulated, you may wish to rethink your lighting , the joys of remolding
