Keep my garage moisture free

-

Evan Dutch

Well-Known Member
Joined
May 11, 2016
Messages
845
Reaction score
289
Location
North Carolina
Hey all,

I had a metal shop put up a little over a year ago. Here it is about 58 degrees and raining. I’m noticing condensation inside (I figured I would, read about it some a while ago). I’ve always had the intention on insulating my shop, guess I should do it sooner rather than later.

As far as that is concerned, I’m not sure which insulation is the best/most cost effective. It’s your typical metal garage, with square tubing as the frame wrapped in panels of sheet metal.

I’ve read about using foam boards and sealing the ends with some kind of gap filling spray foam. When these buildings are sold, the company offers a type of “bubble wrap” insulation. I was told to stay clear if this.

I’ll most likely start with the roof and work my way down, with the goal of doing it as cheap (but effective) as possible.

Any recommendations on insulation material (and techniques for the job) would be greatly appreciated.

Thanks! And merry Christmas!

0C7D248C-BB6C-418F-AE25-9CB48414C88A.jpeg


DCCA7023-28BB-45EB-BBC1-445582FB128E.jpeg


8A3B6DB6-69AB-4F22-AA30-6B319DE00182.jpeg


3696853B-86A8-4320-9620-B010CF7314A5.jpeg


1D50F8D5-6DB8-411F-9535-87F0B01C7C70.jpeg
 
Bring in a spray foam company and stay away from propane heaters. Did you put a vapor barrier under the slab? If not, seal the slab.
 
Bring in a spray foam company and stay away from propane heaters. Did you put a vapor barrier under the slab? If not, seal the slab.
I’ve been told by a metal building supplier that over time, the spray foam will trap moisture between it and the walls and cause the building to rust.
 
After you insulate the building you need to install an air mover . $20.00 floor fans from home center will do in the short term . If you choose to install A/C , that will prevent condensation . gotta keep the air moving
 
Hey all,

I had a metal shop put up a little over a year ago. Here it is about 58 degrees and raining. I’m noticing condensation inside (I figured I would, read about it some a while ago). I’ve always had the intention on insulating my shop, guess I should do it sooner rather than later.

As far as that is concerned, I’m not sure which insulation is the best/most cost effective. It’s your typical metal garage, with square tubing as the frame wrapped in panels of sheet metal.

I’ve read about using foam boards and sealing the ends with some kind of gap filling spray foam. When these buildings are sold, the company offers a type of “bubble wrap” insulation. I was told to stay clear if this.

I’ll most likely start with the roof and work my way down, with the goal of doing it as cheap (but effective) as possible.

Any recommendations on insulation material (and techniques for the job) would be greatly appreciated.

Thanks! And merry Christmas!

View attachment 1715656676

View attachment 1715656677

View attachment 1715656678

View attachment 1715656679

View attachment 1715656680
Start using that big fan sitting in the corner, then a wood stove when needed. Works well.
 
Warm moist air on a cold surface equals dew point, or condensation. The insulation keeps the heat in, but it also keeps the cool in as well. Insulating and vapour barriering the walls and ceiling will keep the walls and roof from condensing (thermal break). Unfortunately when you inject humid air in the summer when the inside if the shop is still relatively cool, you'll still get condensation on cold metal, and concrete (relatively speaking of coarse). Just think of your toilet tank in the summer. I used spray foam in my shop. It works great but it is expensive. And....I keep the door closed when the humidity goes up outside. Good luck.
 
Insulate and climate control.
I recently had my residential 3 car garage, also in NC, sprayfoamed, during the new construction.
Upgraded the garage doors to the insulated type. Have to Sheetrock over the cured foam for the fire rating.
The best thing about it is now I can Cool and Heat with a 12,000 BTU split AC unit set up, for around $900.
 
Last edited:
After you insulate the building you need to install an air mover . $20.00 floor fans from home center will do in the short term . If you choose to install A/C , that will prevent condensation . gotta keep the air moving
My building is 720sqft, would two small box fans from the local home improvement store be enough? I would like A/C but anything greater than a window unit would be unlikely.
 
Start using that big fan sitting in the corner, then a wood stove when needed. Works well.
A wood stove would be nice, I’d like to find one that seals well and has a fan built into it to help circulate warm air. It’s on my list of things to do before next winter
 
Last edited:
Warm moist air on a cold surface equals dew point, or condensation. The insulation keeps the heat in, but it also keeps the cool in as well. Insulating and vapour barriering the walls and ceiling will keep the walls and roof from condensing (thermal break). Unfortunately when you inject humid air in the summer when the inside if the shop is still relatively cool, you'll still get condensation on cold metal, and concrete (relatively speaking of coarse). Just think of your toilet tank in the summer. I used spray foam in my shop. It works great but it is expensive. And....I keep the door closed when the humidity goes up outside. Good luck.
Would the vapor barrier be placed directly on the metal walls, then my insulation material of choice would be installed over the vapor barrier?
 
Insulate and climate control.
I recently had my residential 3 car garage, also in NC, sprayfoamed, during the new construction.
Upgraded the garage doors to the insulated type. Have to Sheetrock over the cured foam for the fire rating.
The best thing about it is now I can Cool and Heat with a 12,000 BTU split AC unit set up, for around $900.
Do you have a typical metal building structure like mine? How would you affix the sheet rock to the framing?
 
Bring in a spray foam company and stay away from propane heaters. Did you put a vapor barrier under the slab? If not, seal the slab.
Would you only stay away from propane heaters? Or any heat source that involves combustion, that creates moisture correct?
 
Find a company that can spray on the two part foam. We have Quonset hut metal buildings at work that have been there for 50 years and they are not rusted from the foam.
 
You can counter the effects a lot of different ways. Keeping the heat/cooling at a constant temperature helps. You can use dehumidifiers to keep the moisture level down so things don't condensate. You could move to a drier climate.
 
Evan Dutch,
No, I had standard stick built residential construction.
What do the "steel building" manufacturers offer for insulation?
Im sure they would offer an option or there's an aftermarket solution.
 
Evan Dutch,
No, I had standard stick built residential construction.
What do the "steel building" manufacturers offer for insulation?
A material that resembles bubble wrap. It’s usually white or clear. And is quite expensive for what it is
 
My shop is all wood construction and insulated. It still draws moisture because of a second floor and no ridge vent. Stay away from the foam its a fire hazard. Space heater with thermostat set at 40 or a coal stove. We had to do this or the machines sweat going from hot to cold. This barn was foam insulated. It went up in seconds and the owner a friend burned with it.

We have a coal / wood stove. 3 shovels every 12 hours. Keep the metal warm. Moisture is our enemy here

DSCN1854.JPG


DSCN1855.JPG


DSCN1112.JPG


100_0398.JPG


safe_image.jpg


DSCN1447.JPG


DSCN1448.JPG
 
My shop is all wood construction and insulated. It still draws moisture because of a second floor and no ridge vent. Stay away from the foam its a fire hazard. Space heater with thermostat set at 40 or a coal stove. We had to do this or the machines sweat going from hot to cold. This barn was foam insulated. It went up in seconds and the owner a friend burned with it.

We have a coal / wood stove. 3 shovels every 12 hours. Keep the metal warm. Moisture is our enemy here

View attachment 1715656697

View attachment 1715656698

View attachment 1715656699

View attachment 1715656705

View attachment 1715656706

View attachment 1715656713

View attachment 1715656714
Terrible about the fire

Thats an impressive shop you’ve got, large stove too!
 
Learned a little about the spray foam insulations. So theres a couple types of spray foam options. Closed cell, for walls and open cell, for underside of roofing.
I was told the open cell allowed water to permeate and drip, IF a roof developed a leak. If the water wasn't allowed to leach through at the roof area, you may never know or find a leak...it could potentially migrate down to a lower wall area, undetected.
Plus the closed cell is a more expensive chemical process, so I was told.
 
Learned a little about the spray foam insulations. So theres a couple types of spray foam options. Closed cell, for walls and open cell, for underside of roofing.
I was told the open cell allowed water to permeate and drip, IF a roof developed a leak. If the water wasn't allowed to leach through at the roof area, you may never know or find a leak...it could potentially migrate down to a lower wall area, undetected.
Plus the closed cell is a more expensive chemical process, so I was told.
So you went with open cell all the way around? That’s interesting, I didn’t know that about the foam
 
Dehumidifiers typically work at 65 degrees and above. At 58 degrees they freeze up.
Moisture barrier on the warm side, here in manitoba its on the inside, my understanding the vapour barrier in warm climates goes on outside. Correct?

I thought the foil type insulation was more effective due to its reflective quality, as its only r7 for the single layer.

here is r20 in walls and r40 in attic.
 
-
Back
Top