Insulation question

[rlskfoster]

I had a friend call me today with a question on insulation addition. He was doing some remodel work for a couple and they wanted to add insulation to thier attic. He said there is approximately 6 inches of blown fiberglass insulation. He was wondering if there is any reason he can't go back over the existing blown fiberglass with 6 to 8 inches of blown cellulose.

I don't him that I really didn't know but I did know where to go ask. Anybody got any suggestions or thoughts.

Buster

[Steven Hockstein]

I believe it is acceptable as long as there is no vapor barrier sandwiched in the middle.

Make sure that the insulation does not block any of the vents. I commonly see soffit vents blocked by insulation.

[hausdok]

Hi,

I agree with Steven - no barriers. Cells is heavy though and he's going to lose some R-value when the FG is compressed.

OT - OF!!!

M.

[kurt]

I'll bet he doesn't lose anything significant; the cell will fill in all the gaps that always exist w/ fiberglass & cut down on bypass. I've done this a bunch over the years; works great.

Cellulose compresses on it's owner over the years; that's when you lose the R value by a few points.

And, I freely admit to being a niggling wienerboy for getting this fine tuned.....

[rlskfoster]

Hey thanks for the quick responses! I passed along the responses to my friend. He appreciates it also.

Buster