Insulation, Radiant and Vapor Barriers - insulation questions

Hi all,
My girlfriend just bought a 1940's capecod in northeastern PA, and the exterior walls have...you guessed it, no insulation. I've been reading through this forum and have seen a lot of differing opinions about blown insulation. Now, this house has extremely thick wall surfaces. On top of the studs, there is a 3/8" layer of drywall, covered by a 1/2" layer of concrete wall board, covered by 1/8" of plaster. So, all told the wall is one inch thick. Very hard to tear through, by the way. My questions are these: Will the blown insulation cause these walls to bow, as it would if they were just drywall? Will we need to install a vapor barrier? Any idea of a ballpark figure on how much installation would be for about 100 linear feet, 8 feet high, 3.5 inches wide?

I appreciate any and all replies,
robot

Realistically, you need a vapor barrier between hot and cold, meaning an exterior wall.

However, that's all for new construction. There's no way that I know of to do it in your current situation.

I would also say that in my experience, a good layer of plaster on top of a wall is pretty reasonable insulation in and of itself.

How would you blow in insulation anyway? Do you have access to eves or something that will make it possible?

I would suggest not worrying about insulation unless you are planning on COMPLETELY tearing the place apart, in which case it's a huge job. You would need a lot of insulation (not cheap), drywall, mud, screws, and time.

I lived in PA for 15 years, and although it gets a little chilly, it's not like you're in MA or MI.

My two cents.

Chris

Id say its more in what are you going to do with the home. How long will you be there to get a return on the $$$$ you put into it. Can drill from the outside and blow insulation in the walls. That much wall it wont bow on you. There also is a paint made that will work as a V/B for you thats can help there.



ED ;)

Yeah, we're not planning on staying there for much more than five years. We just had a guy come out for an estimate for blowing fiberglass fill in from the outside, which he assured us will not settle, and the estimate was $1170. However, we would like to sell this house for a tidy profit, so do you know if this will increase the value of the house enough to be worth it?

Yeah, we're not planning on staying there for much more than five years. We just had a guy come out for an estimate for blowing fiberglass fill in from the outside, which he assured us will not settle, and the estimate was $1170. However, we would like to sell this house for a tidy profit, so do you know if this will increase the value of the house enough to be worth it?

Probably won't because unless you TOLD potential buyers, they'd never know either way. And inspectors can't see inside walls... I wouldn't bother.

Chris