Foam Insulation Question

[dpatterson1976]

I have a red iron 30x40 shop that has the typical rolled insulation on the walls and roof. I have created a 18x12x8 room out of lumber inside the shop and I want to foam spray it and add a Window AC.

I have been talking to foam guys and they are all going back and forth on Closed Cell vs Open Cell. Does anyone deal with this stuff that knows what the heck they are talking about? I just need my room foamed but these guys are making it difficult to figure out what I need to do.

Any help is appreciated.


dp

[redtailz]

Closed cell will act as a vapor barrier and add structural strength. You will not need the same thickness as open. I just did my 1800 sqft building with 2" of closed cell then finished with 2" open over top on the walls. Ceiling has 2" closed and 4" of open. If I were to pick one over the other I would choose closed.

[Chief Big Toe]

i am going though the looking for someone to foam mine,,, there is a guy on TBH that got ahold of me, and explained the diffrence... closed is supposed to be better then open
and from what I hear 2" of closed is better then 4" of open...just what I got out of the conversation.. just cannot get anyone to come and it and not rape me on price.... good luck on your search

[wes122984]

i was advised on mine that if it will be finished out with drywall etc then use open cell so it can breath. if not finished out then use closed.

[BiggieSmalls]

I've heard the same on the open vs closed. Open cell if it's being sheet rocked and closed if its being left exposed.

[dpatterson1976]

i was advised on mine that if it will be finished out with drywall etc then use open cell so it can breath. if not finished out then use closed.

Now, this actually makes some sense!

[Dejashoot]

I did 2” closed cell on most walls of my metal shop and 3” on the ceiling and 3” on the west facing wall. I’m near the coast and wanted moisture barrier. I asked for 4” on the ceiling and west wall and the owner of the company wouldn’t do it. Said it was a waste of money - that’s what they use on walk in freezer walls.

[TD2000]

Built out 40 ft high shipping container with 2" closed and 1 layer of batt insulation under paneling (R31)

Stays nice and cold in summer and warm in winter with only 1 ac and plug in heater for winter

You will be glad to go big on insulation in TX

[mmoses]

In your case it doesn't matter.

Like others have said. Closed-cell will act as a vapor barrier.

You don't need to have your walls breathe.