# Re-Insulating 1960's Attic - Vapor Barrier, and General Input Requested



## Windows on Wash (Aug 30, 2011)

Foam, in the case of a traditional vented attic that is accessible, is huge waste of money if you use it for anything but air sealing (speaking about the floor layer).

Spot seal with foam and/or caulk all the top plates, penetrations, etc.

Open up the soffits if you can and install a ridge vent when do the roof. 

R-60 cellulose is probably overkill but if you are doing it, its is pretty cheap. R-50 is E-Star and sufficient.

Be sure to use a borate only stabilized cellulose.


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## phoenix_iii (Nov 30, 2012)

Windows on Wash said:


> Foam, in the case of a traditional vented attic that is accessible, is huge waste of money if you use it for anything but air sealing (speaking about the floor layer).
> 
> Spot seal with foam and/or caulk all the top plates, penetrations, etc.
> 
> ...



Yes. Looking for foam for AIR SEALING ONLY. Was thinking though, can't I use a combination of Great Stuff + rigid foam to achieve the same thing for less coin (DIY, if I spray foam, I'll hire it out). 

I do not have soffits in this roof, I was told some would be installed when the roof is redone.

What do you think?


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## joecaption (Nov 30, 2011)

Got a picture of the roof and the soffit area?
I've neven once seen a roofer add soffit vents.


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## phoenix_iii (Nov 30, 2012)

No picture handy. When I go up there and pull all the insulation out I can show that there are no soffits. I was told that by the home inspector (I think) that when the roof is redone they can add soffits.

It has 2x gable vents on one side and 1x on the other (where I put the fan), so I think ventilation is adequate. It's small, maybe 900sqft.

I keep getting told I don't need to airseal (either with plastic, or a full layer of 1'' foam).

I think I am going to use GreatStuf in a can to seal the sheetrock to joists, any place air could slip in, and then just blow cellulose over that. So basically a ghetto air seal to prevent 'air washing'... Thoughts?


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