Barn insulation

[MarkV]

BayRat,

For what it is worth, here is my two cents. You have one of your 40’ walls framed with wood studs so no problem there. I would go ahead and frame out the remaining bays with 2x4 on 24” centers. It seems to me that the added cost of the 2x4’s will be off set in several ways. You can use standard fiberglass bats, which I would think will be cheaper than 8’ wide bats and much easier to work with. You solve the problem of nailing surface for your interior covering (Plywood, drywall, metal) which you will need to add anyway. The stud wall will offer you a way to hang benches, shelves or whatever you require in a workshop. If you plan to run power the studs provide mounting for outlets and switches. I also think you will create a better thermal envelope with a bottom plate in contact with the floor surface. (I would still foam as many opening as I could find before insulating)

I know it sound like a lot of extra work, but I sure think you will have a warmer, more functional shop for many years to come.

MarkV

 

[Bayrat]

<font color=blue>I am beginning to think that way myself. A carpenter friend of mine is going to take a look at it to lend some ideas. He lives a ways from here and doesn't want to do it for hire but is willing to advise.

 

[MarkV]

Bayrat,

You said earlier that you did not have a great deal of carpentry experience, but I think you will find that it is not that bad of job. Have your buddy take a look and talk you through the lay out and how to attach to the existing structure. Keep in mind that the structural members are already in place so any engineering concerns are already taken care of. You are just filling in to hold insulation and provide nailing surfaces. We sometimes call it “dead wood” in the trades.

I’ve been a carpenter for a good number of years now so if any questions come up just drop me a message.

MarkV

 

[Bayrat]

<font color=blue>Thank you Mark, I will drop a line should the need arise. I spoke with him as you suggested and he thinks I could pre- build the walls and then set them into place. I could use economy 2x4's, build the first wall 8' tall and then a second at 6' to make the 14' ceilings. He suggests stapling a vapor barrier to the outside of the stud wall towards the steel. I will use the 24" centers and fiberglass as you have suggested. How does that sound, don't plan on starting for awile now anyhow? I sure wish I could figure out how they converted those spray on foam figures though. Me thinks perhaps someone might have thought I had a sucker tattoed to my forehead.

 

[beenthere]

I would put the vapor barrier on the warm side of the insulation. If the room is to be heated, then the warm side is on the inside, towards the heated room.

 

[Bayrat]

<font color=blue>In other words, seal the studs and insulation with the plastic on the drywall side?

 

[MarkV]

Bayrat,

Sounds like a good plan for building the walls. For sure pre-build them on the floor and then raise them. You could even build a group of them a head of time and then get some help to raise them. I had not thought about building the walls with an 8’ section and a 6’ on top, but that sure would work. It would be a lot easier to handle and should help stiffen things up.

I agree with Beenthere and would put the vapor barrier on the inside.(heated side) The idea is to keep the damp warmer air out of the insulation. Insulation loses much of its effectiveness if it gets moist.

We don’t see much of the sprayed foam insulation down here in the South. Our climate just isn’t severe enough to motivate people to spend the extra money. It does seem, from what others said, that they were pricing you pretty high. Is there any other insulation contractors in your area that you could get a bid from?

MarkV

 

[Egon]

Bayrat:

Is it possible to put horizontal strapping like 1x3 in. on the inside. Could be easier and cheaper than building a stud wall.

Egon

 

[MarkV]

Bayrat,

You got me thinking about the spray foam pricing and here is what I think. They were saying, <font color=blue> it will cost 79 cents a running foot for 1 1/2".</font color=blue> I would guess the salesman planned on filling the walls 3 1/2”, a normal stud depth plus another 1 1/2” for the depth of the stringers. That would raise the price to $2.37 per sq/ft or about $1900 for 800 sq/ft. From what I have read about the foam applications, they don’t have the control to just put an 11/2” on in a consistent way. I believe they fill the stud bays until the foam expands just past the studs and then use a tool that shaves it flush with the surface. This is just my guess but it does get thing pretty close to the numbers you were given.

MarkV

 

[StoneHeartFarm]

Bayrat

How does the cost of sprayed on foam compare to rigid sheet foam? Either beadboard or pink/blue board? The interesting thing about beadboard is it can be ordered in just about any size, there's a place near here that tells me they can order blocks 4'x4'x32'. Also, beadboard comes in a number of different "weights" (measurement based on weight per cubic foot). The heavier the weight, the greater the insulation value. Foam also tends to increase R Value at lower temperatures. Typically, R is measured at something like 75 degrees. Foam actually increases at lower temps. Fiberglass decreases.
The problems with it are cutting it (sawzall with a LONG blade works but makes lots of dust, hot knife also works but makes for lots of burning eyes, lungs and eventual headaches ), and Sealing between panels and posts would require cans of spray foam. Plus, Paul has it right, ya still gotta cover it with something, which would require working in studs.

SHF