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rc93
Blowing Cellulose into Wall with Some Insulation

In blowing cellulose insulation into exterior walls that have some thin (1/4 in) insulation with a kraft backing already, where should the new insulation be blown? Between the insulation and the sheathing? Between the Kraft backing and the plaster? Both?

I would like to keep the vapor barrier on the inside of all insulation, but this is leaving a lot of unfilled space in the wall since the existing insulation is nailed to the sides of the studs and lies right up against the sheathing. The backing won't expand enough to fill the whole space.

rc93
Re: Blowing Cellulose into Wall with Some Insulation

My understanding now is that the kraft backing doesn't form a very good vapor barrier at all, so it is probably okay to put the insulation on both sides.

However, will try to drill 2 holes first and then push back the existing insulation thru the holes and then blow in thru the 2 holes.

foammaster
Re: Blowing Cellulose into Wall with Some Insulation

you may want to think about injection foam. that way you won't have to redo it in year
injectionfoam.com

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