I'm planning on adding a layer of insulation to the attic. There's an existing ~6" or so on the floor of the attic, between the rafters. It's old and probably the original.
I'd like to add another layer.
Would it make sense to roll out another layer on top of the original at a 90=B0 angle to the rafters, or, put a layer up against the roof and between those rafters?
Sure...
or, put a layer up against the roof and between those rafters?
No.
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I'd like to add another layer.
Would it make sense to roll out another layer on top of the original at a 90° angle to the rafters, or, put a layer up against the roof and between those rafters?
Adding it over the existing insulation is the way to go. Putting it under the roof will bring up possible problems with vapor barrier and it will increase the temperature of the roof which will shorten the life of the roof.
Note: Take any opportunity to increase the passive ventilation of the attic.
To follow up on that, I'd suggest the OP replace bathroom fans now if they need to be and vent them to the outside if not already done. Once there's a bunch of insulation up there those projects are not fun.
Most sense? Blow in another 8" of cellulose.
check out
steve
I'd like to add another layer.
Would it make sense to roll out another layer on top of the original at a 90° angle to the rafters, or, put a layer up against the roof and between those rafters?
Where did he say the current insulation was cellulose?
Doesn't really matter. Taking the insulation above joist level makes attic useless for storage in any case, so go with whatever is cheapest, which is usually blown-in. It took them less than 2 hours to blow 1400 sq feet for me, including setting the tube things for the soffitt vents. The 50 cents a square foot it worked out to was well below the bids for rolled-out batts. I was afraid of it blowing around and drifting, but so far that hasn't been a problem, even in one windstorm that sucked the hatch cover right off the attic hatch in the garage.
aem sends....
It does not matter. The blown in cellulose has some real advantages and tends to reduce air infiltration.
they didn't.
s
They stuff they used in my house is called "stablilized" They actually spray water on with it, like as if they were doing unfinished walls, (about half as much water though) and it makes it stick to itself. #1. It prevents blowing around, #2. It doesn't settle.
steve
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