# Attic insulation over old attic floor



## Maintenance 6 (Feb 26, 2008)

As long as there isn't any old flooring material or old tar paper laying on the wood flooring, it won't act as a significant vapor barrier.


----------



## Ron6519 (Mar 28, 2007)

I'd use blown in or unfaced insulation right over the flooring. It will keep you from storing things on the beefy joists.


----------



## jklingel (Dec 21, 2008)

wood is in no way a vapor barrier. it's perm rating is somewhere around 30/inch. blow in cellulose and have fun. just make sure you air seal like a madman before you do any insulating.


----------



## Wildie (Jul 23, 2008)

I once owned a house with a walkin attic that had insulation between the joists and had a tongue and groove floor on top.
I laid R20 fibre glass bats over top of the floor and it worked quite effectively.
You have to make sure that leakage cannot occur where the joists meet the rafters.


----------



## beffreyj3 (Oct 17, 2011)

Thanks for the advice everyone! Had to delay the actual insulation installation to finish replacing some hidden knob & tube wiring.


----------



## Windows on Wash (Aug 30, 2011)

+1

You must, must, must deal with that first. 

You home will be warm with knob and tube for all the wrong reasons....:furious:


----------

