I am looking for a good/cheap way to add flooring to this attic space without compromising its function. It runs the entire length of the front of the house and we'd like to use it for storage.

Would just bolting plywood or whatever onto the rafters compromise the functionality of the insulation? How do we best handle this?

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1 Answer 1


Decking won't affect your insulation since you're not compressing or otherwise affecting it. With 16" joist centers you're probably fine with 1/2" OSB as a floor, but if you want less flex go with 5/8". 3/4" is probably overkill. You wouldn't bolt it down. Occasional 2" screws would be great--you mostly want to hit the edges to prevent trip hazards.

The usual caveat is to consider the load on your ceiling (not your roof). Ceilings are designed to carry their covering (drywall, plaster), and the insulation and not much else. You need to investigate where the joists actually rest. If they're well supported and not spanning further than what we see here, you're probably fine, to a reasonable extent. I still wouldn't store piles of Nat Geos or your rare brick collection up there.

Depending on your location, consider blowing cellulose into your joist bays to level with the joist tops. It'll add substantial efficiency if you have significant heating or cooling expenses, and it's an easy DIY job. Of course you could also lay R-11 fiberglass batts in there fairly easily as well.


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