Seeking Opinions on this Plan to Insulate an Old House
Hello,
I am insulating and re-siding my 1938 house in Virginia. Wanted to see if the following plan will work. I currently have full-size 2×4 studs, with 1″ diagonal sheathing on the exterior. I plan to put tyvek house wrap, then 1/4″ furring strips for rain screen, and then 9/16″ – 5/8″ lapped poplar siding.
On the inside, a lot of the stud bay sizes are irregular from twisted studs, and rough sawn anomalies. I have come to the opinion that insulweb and blown in cellulose will be the way to go. It seems like I can get ‘green fiber’ locally, and have seen and read about people doing DIY dense pack with rented machines.
The house is 2-over-2, each floor being 420 square feet.
I own a sawmill and dry kiln and will be cutting my own siding. Instead of drywalling the inside, It makes more sense to me to cut and make 5/8″ shiplap paneling on the interior of the studs.
I understand that will not be a great air barrier, but I also am more inclined to let things breath.
Will this work? or will I have moisture problems? I wonder if I need anything extra, maybe a rosin type paper between the shiplap and studs?
Thanks,
forrest
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Replies
Hi Forrest, you’ll definitely want at least one primary air barrier. The dense pack insulation would be helpful in slowing things down, but it certainly won’t stop air leaks, particularly with what I assume you mean to be some sort of shiplap/tongue-groove sheathing.
I happen to have that type of sheathing myself, and have found many people here on GBA suggest a self-adhering house wrap in place of the tyvek. The new Benjamin Obdyke self adhering product comes in at about $0.50 per square foot and is available online. It’s definitely possible (and preferable) to have an airtight assembly and still maintain drying potential.