Condensation

[ovrszd]

My current shop is all metal, vaulted ceiling, wrapped with 6" insulation. It's nine years old and has never "sweat" inside. Temp has never been below 60F degrees inside. I can't attest to what's happening between the R panels and the insulation.

 

[bigtiller]

My current shop is all metal, vaulted ceiling, wrapped with 6" insulation. It's nine years old and has never "sweat" inside. Temp has never been below 60F degrees inside. I can't attest to what's happening between the R panels and the insulation.

Do you add supplemental heat or is that by natural convection? I just had my building insulated and am curious what the temp and humidity might do this winter.

 

[ovrszd]

Do you add supplemental heat or is that by natural convection? I just had my building insulated and am curious what the temp and humidity might do this winter.

Definitely supplemental heat. I use a wood stove when I'm around to stock it. Have a Propane forced air furnace set on 65F.

Side track. If your concrete is insulated you might get by with minimal supplement. If not, plan on adding heat source. Another thing is the desired temp. I hear of guys talking about working in their shop when it's 50F or less. Not me. I'm spoiled. I expect to work in my shop in a T-shirt. Gotta be above 60F.

 

[strantor]

Definitely supplemental heat. I use a wood stove when I'm around to stock it. Have a Propane forced air furnace set on 65F.

Side track. If your concrete is insulated you might get by with minimal supplement. If not, plan on adding heat source. Another thing is the desired temp. I hear of guys talking about working in their shop when it's 50F or less. Not me. I'm spoiled. I expect to work in my shop in a T-shirt. Gotta be above 60F.

Maybe that's why my building doesn't sweat. It sits atop a hellacious slab. I imagine that slab is still holding onto heat that it picked up in 2016.

 

[ovrszd]

Maybe that's why my building doesn't sweat. It sits atop a hellacious slab. I imagine that slab is still holding onto heat that it picked up in 2016.

Elaborate.

 

[strantor]

Elaborate.

What I mean is that maybe My slab has such a high thermal mass that it keeps the interior of the building always warmer than exterior, thereby preventing condensation.

 

[JFoy]

Hey Barnbuilder,

I'm in Davidson County just south of Winston-Salem. I just had a 24x60 metal building raised on a concrete slab and am turning it into a home for me and the wife. To deal with condensation, I had 1in closed cell spray foam applied to the entire interior. Cost was a little over $6K. Four reasons for the closed cell. 1. Water tight. 2. Air tight. Most contractors today will tell you that air leakage is actually more of a problem with heating costs than lack of insulation. 3. Absolutely no condensation issues. 4. My attic space will have R-7 above my ceiling plane.

Also, wooden studs should not make direct contact with the metal building structure studs. It's called Thermal Bridging and is a significant gateway for heat loss. We inset our walls an inch to put styrofoam between the wood and metal.

Another point. Our building has a blue skirt above the white side walls. When the sun shines on it, the white is about 100degreesF while the blue was about 130degreesF. With the spray foam on it, you can't tell the temperature different from the inside anymore.

Now, the biggest problem with closed cell is the house doesn't breath at all and I'll have to install an Energy Recovery Ventilator (ERV) for fresh air exchange. Panasonic and Venmar (Broan) appealed to me most. Plus, with an ERV, you don't have to install fart fans in the bathrooms as you'll use the ERV for that purpose.

So, with the complication of the ERV, is it worth it? I think so. I'll still do all the full pink batt in the walls and blown cellulose for the ceiling plane to code. There are other considerations in this design and you're welcome to contact me or come see the building for more details. Sheetrock and insulation are not up yet so the walls are still exposed.

Hope that helps,
JFoy

 

[RNeumann]

Remember metal doesn’t breathe like other materials......

The Perfect Wall | Building Science Corporation

But here is an idea from the science side of things. Controlling condensation is the goal. Pretending you can stop it typically isn’t.

 

[RayfromTX]

For those interested in RNeumann's great link, check out the referenced material at the end of the article and find those books written by the great building science minds of all time. Also and perhaps more important for a great reference that is easily understandable by the interested layperson, get "Buildings Don't Lie" by Henry Gifford and available on Amazon.

These reference materials offer a clear understanding of the topic of this thread. The misunderstandings expressed here and elsewhere are unfortunate and depending on climate and conditions can lead to problems of durability and indoor air quality. Build wisely by friends.

 

[Barnbuilder]

Well Finally finished this except for electrical. Now they want to add on 16'.