Open Cell Spray Foam Garage/Shop?

[karoc]

Friday, the spray foam company should be at my place spraying 6” both living space and shop space. The shop is 32’x38’ with 12’ ceiling height. It won’t be a condition space, but OC is there for summer heat. What I’m wondering is, will OC absorb moister or humidity? I was also thinking about spraying a coat of white paint just to help protect spray foam. The foam will be sprayed directly to metal roof if that matters. I choose OC cause it’s cheaper and in our climate zone that’s what is recommended. Any thoughts?

 

[kj_mustang]

If you are in a climate that has 50% or higher humidity levels and you do not condition the interior air, then you better have a vented roof/attic.

 

[Augus7us]

Vented roof with spray foam on the roof deck?

I have oc foam directly on the metal roof panels. One year later no issues. Didn't paint it either. No vents…

 

[housewolf]

If the walls are covered, OC shouldn’t be an issue. My insulation is exposed so I have closed cell on the walls & open on the roof. I went a year without conditioned air and the insulation does help some, summer is unbearable without it. I added a mini split last spring so now I can keep it comfortable year round

ETA; if it is exposed, make sure it’s “flame retardant”. I’ve taken a piece of mine and tried to light it with a torch, I’m comfortable with it, it’s fairly hard to burn.

 

[Mike65]

We had our metal shop done with closed cell foam.

 

[Shoester]

My attached garage is all open-cell, walls and ceiling. Walls are covered with drywall, but the ceiling is open. The open ceiling received a coat of some kind of flame-resistant paint. I have not had any issues.

 

[dcg9381]

We have many hangers at our local airport that are constructed like this: Metal building, spray foam, most of it open (un-airconditioned/heated) and a living space. Zero problems that I know about in our climate in Texas.

Spraying 6" in unconditioned space is a bit interesting to me, as you've got ~1100 sqft or so, that's just begging to be "conditioned". IF you're in a spot like me, leaving it w/o air conditioning might be the way to go until all the inspections are passed, as it'd be taxed at residential rate with an AC.

 

[Hank11]

If you can swing the money, go ahead and put in HVAC.

 

[boneill1292]

If the walls are covered, OC shouldn’t be an issue. My insulation is exposed so I have closed cell on the walls & open on the roof. I went a year without conditioned air and the insulation does help some, summer is unbearable without it. I added a mini split last spring so now I can keep it comfortable year round

ETA; if it is exposed, make sure it’s “flame retardant”. I’ve taken a piece of mine and tried to light it with a torch, I’m comfortable with it, it’s fairly hard to burn.

You have open cell on the roof deck? No ventilation? Trying to determine if I should go open or closed for mine.

 

[Hank11]

You have open cell on the roof deck? No ventilation? Trying to determine if I should go open or closed for mine.

It makes a big difference given your climate. What works in Florida may be a disaster in Alaska and the other way around. Keep in mind that the standard practice in your area is likely to be correct.

 

[boneill1292]

It makes a big difference given your climate. What works in Florida may be a disaster in Alaska and the other way around. Keep in mind that the standard practice in your area is likely to be correct.

Fair. tough to get a legit answer out of the contractors that have come to quote me. They have been saying 'whatever you want'... annoying.

 

[billconner]

You can Google "flammable insulation test" and find numerous YouTube videos of spray foam and rigid foam burning quite well.

 

[Hank11]

Fair. tough to get a legit answer out of the contractors that have come to quote me. They have been saying 'whatever you want'... annoying.

Or tell where your building is located and you might get some informed responses.
I know what you mean about dealing with insulation contractors. Keep looking for a good one.

 

[boneill1292]

My attached garage is all open-cell, walls and ceiling. Walls are covered with drywall, but the ceiling is open. The open ceiling received a coat of some kind of flame-resistant paint. I have not had any issues.

Is this holding true? is the attached garage plywood decking? I'm in Des Moines and looking to put open cell on my detached garage roof. Cant find anyone who went open to give a testimonial. Everyone wants to say closed cell.

 

[boneill1292]

Or tell where your building is located and you might get some informed responses.
I know what you mean about dealing with insulation contractors. Keep looking for a good one.

My bad. i wrote a new post but forgot this is an old one. I am in Iowa. Climate zone 5.

 

[SKIPPINROCKS]

In Southeast Missouri my last shop was metal siding and roof. Closed cell sprayed direct to metal on walls, open cell direct to metal on roof. We had hvac and it was very comfortable. My new shop I'm building thats 2x6 construction with osb sheathing and shingled roof they said open cell on all of it was best value. No issues on old shop with open cell or closed

 

[housewolf]

You have open cell on the roof deck? No ventilation? Trying to determine if I should go open or closed for mine.

Correct. It hasn’t been a problem so far. About the only thing I do that ventilation might help with is welding so if I have more than a tack or two, I’ll do it with the bay door open. I don’t think I’d trust any sort of ventilation enough to run an engine (CO) inside for a dangerous of time. If you’re referring to mold, I’m in/out or bay doors open often enough, I have seen no evidence of it.

 

[NakeDiesel]

I built my pole barn about 12 years ago and used open cell foam on the walls and ceiling. I covered the inside walls and ceiling in steel afterwards. I installed my 5 ton heat pump a little over a year ago. It's great in there all year round now. I'm in very humid OK. I kept the shop above freezing by small electrical oil radiators and the occasional use of a propane bullet heater during long periods of below freezing weather.

I run a dehumidifier year round over the last few years as that was the worst part in the summers here, I keep the thermostat at 80 in the summer and 60 in the winter unless I'm out in the shop and need to paint something in the winter.