I am planning to add more insulation to my attic but I am not sure what type of insulation to use. There is about 5 inches of blown in insulation (no vapor barrier underneath) so I definitely need to add a lot more. I was thinking to add fiberglass blankets on top of the existing insulation but I am not sure if it is a good idea since the blown in insulation is not even everywhere. It ranges from 4-5 inches deep in some places and does not reach the top of joists, so there might be a small gap between the two if I decide to use blankets which would be installed on top of joists. Should I use blown in instead of blankets? Also, as I mentioned before there is no vapor barrier underneath the loose fill insulation. If I will add more of the loose insulation or will decide on blankets, is there going to be an issue with moisture and air penetrating the insulation and eventually getting through the ceiling?
Last edited by asmiarowski; 12-22-2010 at 01:52 PM.
Re: Attic Insulation
Howdy consider blowing in celulose over the exisiting bringing the r value up to r48-r60. The cellous will stop air infiltration , is fire retarded and bug and rodent resistant , easy to install and no gaps around the framing that is common with bat...
Be sure to not close any soffit vents, recessed light cans clearance issues, make sure no nob an tub electrical wiring or you have to address it first as it must have air space to avoid fire. Or consider getting a bid to have it installed ... The largest advantage over fiberglass is that fiberglass allows air to move threw it.
Help! Did I install my insulation wrong?
My wife and I just bought a house and I also had a similar issue in the attic, with old blown in insulation covering most of the attic floor. I wanted to up the insulation value up there so i decided to do it myself. Just the floor.
My house was built in the 1940's, and the original insulation was only about 1/2 - 3/4 the way up the rafters on the floor. I went to Home Depot and they told me to cover it with R-20 faced insulation, faced side up.
I went up there and installed it over the existing insulation, but now i've read that the facing should have been faced down or unfaced all together? Do i have to cover the paper with something now that its exposed on the floor? I did a lot of researching but read and heard so many conflicting instructions. I'll be very upset if i got the wrong advice, and I have a feeling I may have.
Any advice would be helpful.
Re: Attic Insulation
Take off the facing or cut slits in it. I'm assuming it is craft faced, the paper type. Leaving the facing on may cause moisture issues.