My attic has very old insulation, which I have been told provides very little R-value. I suspect the insulation was from when the house was built in 1909.

Question: Should I remove this old insulation before putting fiberglass batts or just put batts on top of it? (The beams are 6").

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  • What is the old insulation. – Alaska Man Jan 17 at 22:53
  • I do not know what it is called, it is like little woolly pellets – amphibient Jan 17 at 22:54
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    Blow in cellulose may be a better option. – Alaska Man Jan 17 at 23:02
  • @AlaskaMan was thinking about it but requires a rental. Batts are more laid back work, can be done peacemeal – amphibient Jan 17 at 23:13
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    Given the choice i would rent the machine and blow it. (and i have) Quicker and no fiberglass. Getting batts in the hard to reach places is HARD. – Alaska Man Jan 17 at 23:30

That insulation is most likely what my father-in-law bought for his home in the 1960's. It was called "pouring wool", sold in bags and was very itchy. I was dating his daughter, now my wife of 58 years, and I offered to install it for him. (you can guess why). We did the job in JULY. I wasn't too smart back then. It looks just like that . I would just install batts over top of that insulation. Make sure that you do not cover the soffit vents and do not fill up into the roof joists. They have styrofoam vents that go between the roof sheeting and the insulation. Good luck.


Since it was installed to insulate the room below and though it has become compacted and lost some R-value it still is insulating. How ever little that may be.

Also I would be suspicious of harmful additives used at the time that can cause health issues. Disturbing this stuff will only allow dust to become airborne.

Lastly, why incur the added expense and effort that would come with it's removal? It makes me shudder to even consider it!

Best plan is to seal all openings to the living space below with foam and caulk. If you plan on using rolled insulation lay it parallel to the joists. If you decide on more lay the second layer perpendicular to the first (like plywood is made).

Or you can blow in insulation which is faster,but takes a bit more planning.

Try to achieve a total R-value of 38 or higher if your in a cold winter climate.

  • So are you saying remove the old or leave it? Removal is very easy, can be scooped and put in a bag – amphibient Jan 17 at 23:17
  • @amphibient "Removal is very easy" As some who has tried that i can say, it is not easy. – Alaska Man Jan 17 at 23:32
  • @AlaskaMan I have removed sections already. It's like wool pellets sitting on top of the ceiling – amphibient Jan 17 at 23:37
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    @amphibient- I would never try to dissuade a man to not work. To me it seems like an unnecessary effort and expense. – ojait Jan 17 at 23:38
  • @amphibient-the only upside I can see is it will help to locate openings needing foam. – ojait Jan 17 at 23:39

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