Does anybody have personal experience with IC rated can lights and spray foam insulation. You can put fiberglass over the cans but is it okay to cover them with foam? I am talking about an R30 layer of open cell polyurethane foam.
Listeners write in about fireplaces affecting family harmony and bionic suits, before asking questions about brick steps, ground-source heat pumps, and building a dome greenhouse in Maritime Canada.
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial NowGet instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial Now
Replies
I wouldn't.. simply because of the chance they might have to be changed out at some point in time. I'd tent 'em to create a cavity.
Have no idea if you CAN do it... just that I wouldn't.
Good point! So let's say we have a cathedral ceiling with a couple of inches between the can and the roof sheathing. What would you do there?
I would try to wrap the can in a non-flamable substance to be safe. Fiberglass insulation as thin as possible. Then spray the foam all around it. This will make the can somewhat removable since the foam will not be directly adhered to it. There will be a complete foam cover surrounding it though so you will block the air infiltration. Stu
I would think that is the best.FG pipe wrap insulation should work.
have you asked your installer? they must come across this all the time. i'll be using icynene for the first time, and that will come up on this job, too
_____________________________
HomeBase______________ LLC
Edited 3/20/2005 5:07 pm ET by homebaseboston
Edited 3/20/2005 5:07 pm ET by homebaseboston
Edited 3/20/2005 5:08 pm ET by homebaseboston
Hmm, inquiring minds want to know because I'll be facing the same issue with my installation shortly...
NotaClue
You can cover the can with fiberglass safely, though. Right? I'm puttnig in new cans nowthat are IC rated. Just want to make sure.
Tom
Can one of the FHB editors with experience with Icynene or other open cell foam products offer an opinion?
So, can you foam around and happily use an IC rated can light in a ceiling that has Icynene put into it and around the fixture (no "box") or does even and IC can need a thermo protective box (foil covered on both sides extruded polystyrene or two sheets of drywall for a 1 hour fire stop) around each and every can?
Called an Icynene installer today (SDI in South San Francisco, CA) and he seemed to think every light needed a box...One would think he would know; but it still seems odd!NotaClue
As I understand it, the issue is that the foam is such a great insulator and blocker of air movement that the the cans may get hot enough for the thermal safety switches to cut out. I have rigged a test bench with three IC rated cans covered in foam to test it for myself. I'll let you know how it goes.But, this is clearly a question that the can manufacturers should address. Why don't they????<!----><!----> <!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----> <!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----> <!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!---->
Pure: I'm not a sparky - but - doesn't this kinda walk a fine line on the issue of a J box being inaccessible? I put IC cans in my whole house (Halo's) & every one of them has a J box on it. If buried in FG, they are as readily accessible as you care to get itchy. Buried in foam they are practically isolated. Supposedly you can get access to their box from inside the can, but I sure wouldn't want to. Just from that practical standpoint, I'd tent 'em and leave lots of space around them for big hands & a scwoodwivew.Elmer(Sorry, couldn't resist)DonThe GlassMasterworks - If it scratches, I etch it!
Would they be "accesible" even from the inside if they are enclased in foam?I think that requires moving the can around. And if shot in foam it is casted in place.
In this jurisdiction, our building inspector has changed the sequence of foaming and electrical rough-in.
Since his new requirement is for no wiring to be buried in rigid foam, all our spray-in work is done first, before wiring and can placement.
We are required to frame walls using 2x6 studs or deeper, and typically a foamer is asked to pack out the walls to a 3 inch depth, but if you know foam, you know how that goes. You'll get 3 inches or slightly less at the center of the bay, but there will be corner fillets out to beyond 4 inches.
This places a minor little burden on electricians doing rough-ins, in that there is a lot less room to maneuver the drill and bore those through holes in studs for wiring bay-to-bay.
I haven't had foam shot in a cathedral roof with cans since this new ruling
If anyone was interested, this was the official response from the technical assistance department at Icynene, Inc:Mr. XXXXXXLet me begin by thanking you for your interest in The Icynene Insulation System¯. As you may know, The Icynene Insulation System¯ is an inert low-density (0.5-lb/ft3) open-cell foam plastic insulation that is ideal for insulating residential, commercial, industrial, and institutional buildings. In addition to insulation value, it provides an air barrier to the building envelope that significantly reduces uncontrolled air leakage and thereby improves thermal efficiency in the home and in the workplace.
As listed on our Product Specification (attached), the insulation cannot be installed with 2" of heat emitting devices in excess of 200 degrees F. If this requirement can be met with the IC-rated assemblies, then no additional boxes should be necessary. The local fire code may limit the number of metal IC-rated light assemblies per 100 sqft of ceiling area, so consult with your local code authority to see if additional boxes are required based on your project.
If you have any further concerns, please let me know.Dan Steinbok, B.A.Sc
Building Science Engineer
Icynene Inc.
1-800-758-7325 ext.250
http://www.icynene.com What I took away from this reply was:Spray onto your IC cans if you want to!NotaClue