Attic cleanup and insulation (asbestos, store, move)

[jules178]

Hi all,

I bought a 1958 house, the attic is dirty, insulation is sparse and dirty. I want to clear it out, insulate and plywood most of it so I can store some things up there. The question is, should I remove the old batts or just put the new batts on top? any tips on this project much appreciated!

[BBCjunkie]

Normally you want to remove the old and replace it with new batts. The old stuff is probably so dirty that whatever insulating value it once had is greatly diminished.

Be aware when selecting the R-value of the new insulation that if you are going to put plywood down on top of it, the fiberglas will compress and you won't get as much insulating value as if you had put down a thicker batt (such as the recommended R-38) and left it alone.

Have you ever worked with fiberglass batt insulation before? It can be a nasty job especially the old stuff which was super irritating to any exposed skin and can cause a hellish itch. The new stuff is supposedly better in that regard but I still wouldn't say it's "pleasant" to work with.

What does the existing insulation look like? Is it pink or yellow? If it's gray it may be rock wool which was often used in the 1950s. Not a health hazard. But some types of 1950s insulation products contained asbestos and/or vermiculite (i.e., Zonolite) which is something you do not want to be handling yourself. In that case you have a choice to have it professionally removed OR lay down new insulation and plywood on top of it without disturbing the original material.