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sctclimbs
11-15-2008, 08:20 AM
I am going to be adding insulation to my attic. Planning on using blown-in cellulose to depth of 19 inches. I have 6 can lights up there, they are IC rated. Can I bury them in insulation or is that a bad idea even though they are IC rated? Here is the specific light: http://www.goodmart.com/products/986254.htm

Chris75
11-15-2008, 08:21 AM
That type of IC can I would build a plywood box around. :) Only because of the type of Insulation you were planning on using.

jar546
11-15-2008, 09:05 AM
IC rated is IC rated is IC rated so it is OK for it to touch the insulation:

PROVIDED THAT:

You only use trim kits and bulbs that are compatible with IC rating of that fixture.

If you use the wrong trim and bulbs then the fixture loses its IC rating.

What you are plannin is not a problem at all.

Chris75
11-15-2008, 11:27 AM
IC rated is IC rated is IC rated so it is OK for it to touch the insulation:

PROVIDED THAT:

You only use trim kits and bulbs that are compatible with IC rating of that fixture.

If you use the wrong trim and bulbs then the fixture loses its IC rating.

What you are plannin is not a problem at all.

You dont see a problem with all the blown in insulation entering the can a problem?

jar546
11-15-2008, 11:48 AM
It is rated for that application and its rating does not specify insulation type. He can use batt insulation in that area if he wants.

Aside from the electrical issue, there is an issue of a vapor barrier with the use of blown in insulation. I want to know what he is going to do for a vapor barrier.

jadnashua
11-15-2008, 03:24 PM
If they are IC AT (air tight), the dust from blowing in the cellulose shouldn't present a problem.

sctclimbs
11-15-2008, 04:34 PM
Thanks for the replys. They are not IC-AT, just IC. So how's this. I make a fort of batt insulation around each one and then blow the cellulose over it. That cool?

As to JAR's question of vapor barrier. Bit of a problem there. Currently there is 6-10 inches of blown fiberglass in the attic with no vapor barrier. It has been like that up there for the 40 years the house has been alive. How important is it to have the vapor barrier? I'd rather not have to pull all that stuff up if I dont have to.

construct30
11-16-2008, 02:44 PM
We cover every light box and hole before blowing cellulose in an attic. I blew cellulose in houses for years and have it in my own house. I wish I didn't. The dust will find every way it can into your living space and regardless of what they say some people are allergic to the dust. Do a search and you will see. I would stick with the fiberglass, it stays where you put it.

As for vapor barriers, there is code, inspectors usually know best? What is best? Ask a hundred people and get a hundred different answers. IMO, If you put too much vapor barrier in a house, walls ceilings and everywhere, you will have moisture problems and will need an air exchanger to solve the problem. I like a vapor barrier in the walls and none in the attic with lots of attic vents. We heat more than cool here, environment does determine vapor barrier specs.

sctclimbs
11-17-2008, 07:27 AM
I'm also considering installing a radiant barrier. I'm kind of on the fence though if it is worth the cost and trouble. Anyone one have any opinions on this?

I'm specifically looking at this product by radiant guard. They make a perforated/breathable aluminum barrier that I'd install below the rafters. Will cost me about $150 to do the attic. http://www.radiantguard.com/ultraradiantbarrier1000sf.aspx

jadnashua
11-17-2008, 11:51 AM
I stapled a radiant barrier sheet below the roof rafters...lowered the summer attic temp 30-degrees or so on a sunny day...the ceiling felt room temp rather than like a radiator. Probably better in the winter, too, but I don't have easy access to before and after heating costs related to degree-day useage. I will say that my roof is the last one in the condo complex to lose the snow cover by probably 3-4 days. This tells me that nowhere near as much heat is getting out to the roof.