CommunityAttic Floor Insulation: Adding New Attic Insulation and Floors

Attic Floor Insulation: Adding New Attic Insulation and Floors

We want to add wood flooring up in our attic.  Before doing so, we were going to replace the existing installation.  Are we going to encounter any moisture problems with the new attic installation if we cover it with a wooden floor?  Are there any special precautions we should take?

The Money Pit Answer

When flooring an insulated attic, the most common mistake people make is squishing the insulation. Attic insulation works because it traps air.  Compress that insulation under a floor and the air gets pressed out, robbing the insulation of it's efficiency.
In a perfect world, you'd buy insulation just thick enough to fit inside ceiling joists, floor over and be done.  But, here is the kicker.  Most ceiling joists are simply not deep enough to hold the 15 to 20 inches of insulation required by today's energy standards.
I suggest you only floor the portion of the attic you absolutely need for storage.  For the rest, install 15 to 20 inches of insulation and let it rise above the thickness of the joists.  Also, be sure to use unfaced fiberglass batts, and make sure you have enough attic ventilation to avoid moisture build-up in your newly insulated attic floor.

1 Answers
kitkathouse answered 6 years ago

I really would like to provide a cat walk in my ranch house attic so that they can go up there, walk to the other side of the house and come down through a closet to different bedrooms.

I already have more than 1500 feet of catwalk built with wire shelving which the cats have enjoyed for a year now. It winds up from their basement room, to another basement room, up the stairs to around the utility room, two ways out to the garage and now they have a cat porch made of wire shelving which also was covered with wood and roof paneling for the winter.

We have a coyote problem in the country so this way the cats can never get out yet have a lot of freedom. I, however, would like them to be able to choose if they want to meet me in another room that is away from the dogs. Some of them are terrified of my new Belgian Malinois mix. smile.

Does anyone have advice? After reading here I am thinking maybe the cat walk should be elevated above the joists so as not to flatten any insulation.

I have a small area over the 3 car garage with flooring and shelves to store christmas decorations. This might be too hot for such, but I was not planning on using them again anyway.