Insulating a metal building...options?

[iowa]

Hi.

I have a 70' x 40' x 16' (ceiling height) metal building. The 2"x6" studs are 8' on center. The floor is concrete.

I would like to insulate the building so I can heat it to about 60 degrees on a cold (10 degrees) Iowa winter day.

I have priced spray foam and it is higher than what I would like to pay.

Are there any other options available to me?

Would using foam board insulation work? I understand the material is the same as some spray foams.

Thanks.

 

[dave1949]

I can't imagine foam board insulation would be comparable in performance to the spray foam.

One concern will be the inevitable air gap between the foam board and metal walls and the condensation that may lead too. The other concern is the spray will leave no voids but the foam boards will, because you can't fit them that tightly or bend them to fill any irregularities.

 

[medic0648]

They make fiberglass insulation bats for insulating steel buildings. They are usually lined with plastic on 1 side.

 

[iowa]

I can't imagine foam board insulation would be comparable in performance to the spray foam..

I agree.

One concern will be the inevitable air gap between the foam board and metal walls and the condensation that may lead too. The other concern is the spray will leave no voids but the foam boards will, because you can't fit them that tightly or bend them to fill any irregularities.

There is still the possibility of condensation behind the wooden wall studs that don't get sprayed with insulation. Spray foam insulation is probably the best method at this time but foam board would have to be better option than fiberglass bats--which some people use.

 

[dave1949]

I agree.




There is still the possibility of condensation behind the wooden wall studs that don't get sprayed with insulation. Spray foam insulation is probably the best method at this time but foam board would have to be better option than fiberglass bats--which some people use.

You would be spraying the sides of the studs and the corner made by the stud side and metal, that should seal it fairly well but I agree, it won't be total. Where air cannot go, condensation is going to be very limited.

Maybe you could focus on insulating the ceiling first and see how the building heats after doing that. The ceiling is where the most heat is lost. Is the ceiling closed in, or is it open to the underside of the roof? Closing it in will reduce the air volume to heat and keep the warm air closer to you down below.

 

[iowa]

Maybe you could focus on insulating the ceiling first and see how the building heats after doing that. The ceiling is where the most heat is lost. Is the ceiling closed in, or is it open to the underside of the roof? Closing it in will reduce the air volume to heat and keep the warm air closer to you down below.

That was an option I posed to the spray foam companies that gave me quotes. They said they would not even do the work if that is how I wanted to proceed. They 'said' that I wouldn't be satisfied with the results.

The building does have a metal ceiling below the roof.

I've even wondered if I could somewhat heat the building with just a couple of forced air furnaces when I needed to heat it.

 

[dave1949]

That was an option I posed to the spray foam companies that gave me quotes. They said they would not even do the work if that is how I wanted to proceed. They 'said' that I wouldn't be satisfied with the results.

The building does have a metal ceiling below the roof.

I've even wondered if I could somewhat heat the building with just a couple of forced air furnaces when I needed to heat it.

Well, the foam sprayers are generous with your money. :laughing: They may fear you would blame them if the building wasn't warm enough to suit you.

Exposed 16' metal walls are going to be chilly no doubt, but the ceiling is what traps whatever warmth you put in the building and would be the logical place to start if you want to spread out the costs over a couple of years. Is there a vapor barrier on the metal ceiling panels?

With a vapor barrier you could blow in cellulose yourself and get good results. You can rent the shredder/blower or it may be provided free from where you buy the cellulose. It's a two man job, one to work the hose and another to feed bales into the blower.

I'm sure with enough btu's, you could take the chill off a work area with forced air if that's all you need to do.

 

[tcreeley]

I've read that spray foam gives off toxic fumes in enclosed areas and needs to be sealed or well ventilated. Maybe the new stuff is better than the old. I like fiberglass bats and a second interior wall. Figure out you vapor barrier situation to avoid condensation inside the wall area.

 

[RedNeckRacin]

so can you put up board insulation across the bottom of the trusses before the walls are sprayed in? Or is it worth the additional cost to spray everything?

 

[bandaidmd]

After you get it " sprayed" do some research on infrared heating, with those tall ceilings most of your heat will be over your head.
Infared is fueled by lp or nat gas in long tubes and warms objects not the surrounding air, just like the sun does.

 

[MotorSeven]

I've read that spray foam gives off toxic fumes in enclosed areas and needs to be sealed or well ventilated. Maybe the new stuff is better than the old. I like fiberglass bats and a second interior wall. Figure out you vapor barrier situation to avoid condensation inside the wall area.

Not so with the newer stuff.

Iowa, I know spray foam is pricey, but it really is a great product that does a fantastic job. I had it sprayed on the apartment side of my Quonset Hut. The area sprayed was 30x14' and we used a single cube heater each winter for 5 years to keep us warm. Looking back I wish I had gone ahead and sprayed the shop side & some day I will. It is still bare metal and takes a lot of wood to heat it to "working temps".

 

[iowa]

so can you put up board insulation across the bottom of the trusses before the walls are sprayed in? Or is it worth the additional cost to spray everything?

I'm not quite following you. There is a ceiling in the building. I would put board insulation on the attic-side of the ceiling.

After you get it " sprayed" do some research on infrared heating, with those tall ceilings most of your heat will be over your head.
Infared is fueled by lp or nat gas in long tubes and warms objects not the surrounding air, just like the sun does.

Thanks for the reminder about infrared heat. I had read a bit about it a few years ago. I've never seen it 'in action' so I have been skeptical of the claims.

Iowa, I know spray foam is pricey, but it really is a great product that does a fantastic job. I had it sprayed on the apartment side of my Quonset Hut. The area sprayed was 30x14' and we used a single cube heater each winter for 5 years to keep us warm. Looking back I wish I had gone ahead and sprayed the shop side & some day I will. It is still bare metal and takes a lot of wood to heat it to "working temps".

How tall was this portion of your Quonset Hut? Is a cube heater different than a space heater that has coils that heat up with electricity?

 

[Dr Dave]

The ceiling is the easy part, just get a blower from Menards or lumberyard and blow in fiberglass. You want a min or R38.
Be sure the atic space is vented

For the walls you can get fiberglass in 150ft roles in widths up to 8 ft, it has a white plastic on both sides. It is fire rated and can be left exposed. R19 would be the min.

Dave

 

[Dr Dave]

As for heating, infloor heat is the best. The radiant tube heaters work great also, I have worked in both, far better than forced air.
Radiant tube heaters heat the objects in the room, if you open a door, the recovery time is much quicker than forced air.

Dave

 

[iowa]

The ceiling is the easy part, just get a blower from Menards or lumberyard and blow in fiberglass. You want a min or R38.
Be sure the atic space is vented

That's exactly what I had planned doing myself in the ceiling...until the spray foam contractors told me that they would only do both the walls and ceiling. The attic does have soffit vents and a cupola and ridge vent.

For the walls you can get fiberglass in 150ft roles in widths up to 8 ft, it has a white plastic on both sides. It is fire rated and can be left exposed. R19 would be the min.

Dave

I did not know that I could get 8ft wide fiberglass bats. Thanks for the info.

Do you think there would be an advantage of fiberglass bats over foam board for the walls?

 

[iowa]

As for heating, infloor heat is the best. The radiant tube heaters work great also, I have worked in both, far better than forced air.
Radiant tube heaters heat the objects in the room, if you open a door, the recovery time is much quicker than forced air.

Dave

Are radiant tube heaters typically hung from the ceiling or are they mounted closer to the floor?

 

[Danno1]

Are radiant tube heaters typically hung from the ceiling or are they mounted closer to the floor?

Around here the HD's and Lowes have radiant heaters up by the ceiling over the cashiers. Maybe 15-20 feet up. Even with the entry/exit doors opening and closing constantly, you can feel them when you're checking out. And we get plenty of single digit winter temps here.



.

 

[medic0648]

The fiberglass is fire rated, the foam board is a serious fire hazard unless covered by something fire rated.

 

[jwstewar]

Keep the thoughts coming guys. I'm watching this thread with great interest. We are getting ready to build a pole barn (hopefully starting next Thursday) for our goats. It will have the "bubble wrap" insulation under the metal roof, but it will also have soffit vents and ridge vents. Eventually I may look at ceiling for it, but at the same time that is the point of the soffit and ridge vents to vent the animal "fumes" I'm actually a bit more worried about heat build up in the summer than I am cold in the winter.

 

[JerryK]

You have to sit down and have some serious thoughts about how critter proof you are going to keep your barn first. Any critters, and some insulation types just provide nesting and tunneling places... which also degrades the insulation over time...