[NorCalNate]

We are completely restoring a single story, 3bd/2ba house. We live at 2800ft in California (climate zone 2 or 3). The house has board and batten siding (either rough pine or cedar). The house is wrapped with some type of weather barrier, followed by the sheathing. Attached to the back of the sheathing is an asphault/felt barrier (surprisingly in very much in tact). The studs are 2x4. The house walls cavities were never insulated.

My head is exploding reading all the articles out there about insulating old houses. I've been trying to figure out if the asphault/felt barrier means we have to leave an air barrier between the sheathing and insulation or if we can put insulation directly inside. We don't know if the asphault/felt barrier will allow vapor to pass through from the exterior which is causing all the questions.

Also, I'm not sure if I should seal the battens to the boards, or re nail them and allow them to breath.

Help!!

 

[Nealtw]

The tar paper is mostly for water that gets passed the siding.
If you run AC most of the time, you do not want out side air coming thru the walls.
The way it has been any air that gets in can get out. When you add insulation you want a real goof fit with the insulation and stop air flow from at least one side.

 

[NorCalNate]

So what type of insulation would you use in this situation?

 

[Randy Bush]

Are you sure that is just tar paper you are seeing on the inside? the seams look to even, almost looks like the exterior grade sheetrock they use to use. It was wrapped with a tarpaper type of of material 2 ft wide sheets.

 

[NorCalNate]

I dont know for sure, though you think it may be exterior sheetrock with tarpaper? The house was built in 1958. I definitely have noticed “seems” which look like theyre 2 feet apart. If this is what we have, any suggestions?

 

[Nealtw]

Are you sure that is just tar paper you are seeing on the inside? the seams look to even, almost looks like the exterior grade sheetrock they use to use. It was wrapped with a tarpaper type of of material 2 ft wide sheets.

Good eye! Could be Gold Bond, Beaver board or Buffalo board, some of them might have asbestos in them so not to be disturbed if possible.

 

[NorCalNate]

Gotcha thanks for the info. If they are beaverboard, any recommendations on insulation?

 

[NorCalNate]

Thank you for all the info

 

[Nealtw]

Gotcha thanks for the info. If they are beaverboard, any recommendations on insulation?

Just caulk all the joints from the inside and use a rockwool or fiberglass insulation