Insulating a Workshop

Sun Jan 01, 2006 5:32 pm

Anyone have any suggestions on the best way to insulate a 12 X 24 metal building with metal studs?

I want to put in a small heater, but want to insulate it. When I bought the building, I got the one with metal studs because it was significantly cheaper since the maker was trying to introduce his line with metal studs. Little did I realize how much trouble I would have in trying to figure out how to insulate it. It doesn't get really cold for an extended period in my part of NC, but I believe that it would help the heating.

I am going to cover the insulation with a thin panel, but don't look forward to cutting 2X2 sections of roll insualtion for the ceiling. All wall studs and rafters are 24" on centers.

I have looked at the 1 1/2-inch rigid foam, but it is very expensive. I have thought about the spray-in foam, but don't know if it would be any cheaper.

Any suggestions will be appreciated.

Sun Jan 01, 2006 8:53 pm

I would have to imagine you can find roll insulation wide enough for what you need. You may have to contact your local lumber yard instead of a "lowes" or "home depot" that have a limited selection of insulation. If your talking about expanding foam insulation its expensive and can be "dangerous" Ive seen people try to fill in holes in walls and whatnot with it and they spray it in and fill up hole then it expands and it pushes out and breaks there drywall or whatever its more powerful then you would think. When you use it you only fill your hole up roughly 30% and let it expand the rest or you will have problems. Also remeber the insulation that you blow in if not in a horizontal position like in your attic is going to settle. You blow that in your walls and its eventually going to lose its fluff and just settle to bottom of wall. Im not a "insulation man" but we own a heating and air business. Good luck....

Sun Jan 01, 2006 8:56 pm

Insulating the ceiling will also depend on what type of roof you have on it (metal or asphalt). Ask a construction friend on how to properly do it if its asphalt (shingles) especially. Insulating a wooden roof with shingles could rot it out pretty fast and warp shingles. :D

Sun Jan 01, 2006 9:22 pm

When we were kids we put up stryofome sheet insulation on the bottom of the roof joists. We got a lot of air leakage at the eges of the panels. And naturally just about burnt the garage down when we had a little fire on the work table. The foam panels started melting and just about cought on fire too before we got it out. Needless to say I am a firm beliver in drywall in the garage or shop.


Sun Jan 01, 2006 9:30 pm

Blown insulation doesn't have a settling problem if it's done right. It must be blown to a greater density than its' own specific density. A bigger problem would be moisture. Vapor will travel through it until it condenses near the impervious metal siding... and stay there forever... or until the building corrodes down. Humidity control in the walls of a metal building can be a serious problem, since there is no way for it to escape.

We became dealers for cellulose blown insulation over 40 years ago and hate to see it mis-used.

Insulating a Workshop

Sun Jan 01, 2006 9:35 pm

You might want to try an insulation called "Tuff-R" I think that you can get it in 3/4" 4'x8' sheets. One side is a silver foil which goes towards the work area. Very good for reflecting light. The seams are taped with foil tape.

Good Luck!

Sun Jan 01, 2006 9:40 pm

If you have enough head room - suspended ceiling (same stuff they use for ceilings in houses) with batt insulation laying on top of the ceiling.


Mon Jan 02, 2006 8:18 am


I am using the super tuff r in 3/4 inch it is R-5 in that thickness and $10.50 a 4x8 sheet. My house was buil without a sill plate the floor joists sit on the block wall with a face plate to the outside. The original house was built 1933 and their are 5 additions and nothing was done correctly in the entire house. The wind blows under the face plate through the core of the block and across the basement. Also the block is cracked and shifted. So I am running the sheeting up to the floor and cakling arount the floor joists. And glueing the tuff r to the wall. I have a michigan basement its 5' to 6' high between the ground and the floor joists.

You know how it is with your first house and think you can just go ahead and fix everthing. Oh well I love the seven acers and spend as much time as possible outside.


Mon Jan 02, 2006 4:02 pm

Does the shop have a pitched roof? I'd install a venting system there to control the transfer of heat and cold. You install a baffle in the rafter space. There needs to be a way for air to come in, like vents in the overhang, and then a ridge vent or equiv at the peak. The other half of the rafter space can be insulated and then covered.

I did this at our previous home for the walk up third floor and the upper level of the detatched garage. What an improvement. Both rooms got "pass out" hot in the summer, and icey cold in winter. After the venting install, very comfy.

Mon Jan 02, 2006 9:46 pm

Use the sheets that Cowboy suggested. ( i am in a similar situation that he is in, 8 acres with an old house.) I just ran electricity to my barm after 4 years and now heating is going to be concern. I have figured that those blue styrofrom looking sheets with moisture resistant drywall should do the trick. ( videodoc just did a nice barn ) I have a few freinds that live in NC and they tell me that it gets to freezing once in a while. How big is your barn? Do You have vents in your roof? HOw much time are you giong to spend in there? On demand heating is the way to go for the climate you live in. I also have learned that investing in a good set of carhart coveralls is way cheaper than barn heating bills.

Insulating a Workshop

Tue Jan 03, 2006 2:17 pm


I know what you mean. The house I live in has issues as well! And we both know how crazy the weather gets up here.

When I built my shop, I put the trusses on 24"centers. That way I could use the faced fiberglass bat insulation. I had a lot of cutting to do but I think that the "R" value that you get from the fiberglass is worth it. Its naturally cool in the summer and warms easy in the winter. My shop is 32' x 40' with 11'6" to the celing.

I am lucky to have natural gas. A friend of mine got me a 195000 btu hanging furnace out of a building that they were remodeling.

Tue Jan 03, 2006 6:26 pm

my friend had his sprayed it is a all metal building it looks like foam that you spray out of a can, however they did it with a big airless outfit and he has no moisture problems or any other problems at all going on 5 years now

Tue Jan 03, 2006 7:51 pm

about 35 years ago our county highway deaprtment had a shop that had spray in insulation. was a blue color, and was fluffy, but don't know what kind it was. One day they discovered it was a lto more flammable than it was advertised as. sparks form a selder caught it on fire, and the building and all the trucks wer elost in a matter of minutes. employees just barely managed to get out.