Insulating a steel building?

[Hobby_Man22]

Looking at the insulation zoning maps online I'm in zone 2 here in Houston. So they call for R30-R60 in the attic and R13-R15 on the walls. Now would those same specs be applied to a steel shop building? It's a 1500 sq ft building 12ft tall with a 5 ton hvac system. I do want to be able to set the thermostat to the same setting you would in a house so like 75 degrees or so.

 

[GTSDave]

Going to watch this thread. I dont plan on putting AC in mine, but I do want to insulate it. Preferably with spray in foam. My slab is poured but the building wont go up until after Jan 1st. Been calling around for quotes to get spray foam quotes, and no one replies or calls back... I SW of Houston in Ft. Bend county. Curious to see what responses you get.

 

[Hobby_Man22]

Why does everyone use spray foam? That stuff is expensive

 

[86turbodsl]

And there's nothing better. An inch of spray foam is worth several inches of fiberglass in my experience. The pure R value doesn't really describe the capability of it. Infiltration is ZERO in a properly done spray foam building and that's worth like 1/3 to 1/2 the heating/cooling capacity. For instance, i have a 3000 ft2 house with 2.5 inches of spray foam in the walls, which is ~ R18.5ish with a foot of cellulose on top in the attic. That's a total of ~ R60 ceiling and R18 walls. I heat this house with ~50,000 btus. Design temp is 0F, that's a 70 degree delta T. If you're in Houston, I'd imagine your cooling delta T is ~ 40-45F. That's easily within a 5 ton unit's capability. Heck, maybe even 3 tons.

 

[readhead]

It’s pretty well known that I am not a fan of spray foam in metal buildings because of the potential for future damage. I like spray foam but just not applied to metal.
You should be discussing this with your building supplier. All your requirements can be met easily with fiberglass for a lot less money.
I will void any warranties for any of the buildings I sell if spray foam is applied at any point after we finish.

 

[Hobby_Man22]

It’s pretty well known that I am not a fan of spray foam in metal buildings because of the potential for future damage. I like spray foam but just not applied to metal.
You should be discussing this with your building supplier. All your requirements can be met easily with fiberglass for a lot less money.
I will void any warranties for any of the buildings I sell if spray foam is applied at any point after we finish.

It's hard to find contractors in my area. I called like 4 people and nobody called back.

 

[AP514]

I used Spray in CELLULOSE..in my steel framed House here in Pearland 17 years ago.
So I have R30 walls and loose Fiber in ceiling R40+.

Here is a pic of the insulation on the Wall in my attic(brown)

 

[Cougar]

It’s pretty well known that I am not a fan of spray foam in metal buildings because of the potential for future damage. I like spray foam but just not applied to metal.
You should be discussing this with your building supplier. All your requirements can be met easily with fiberglass for a lot less money.
I will void any warranties for any of the buildings I sell if spray foam is applied at any point after we finish.

Thought I read on GJ that spray foam was better on steel.
One reason, it would stop condensation?

 

[dcg9381]

Why does everyone use spray foam? That stuff is expensive

It can be installed quickly and works well on a roof (without an attic). The rest of it is that there is more to insulation than R-value. Foam gets in all the nooks and crannies and provides a sealed envelope. The real answer is in the utility bills if you compare a foam house to a traditionally insulated house with the same R value.

Some advantages to putting the air handlers and vent envelope into the heated/cooled space in residential (compared to a hot attic).

 

[BKB]

I paid $500 for them to house wrap my 40x64 barn. That way you could spray foam and panels can be replaced if needed. The cost of the spray foam was about equal to the cost of the barn so blown in and 24" batts were used.

 

[skamin20]

following: In SW Iowa, zone 5, pretty cold winters. Have a quote for closed cell for my 40x40x14 building. Have radiant heat tubes in concrete ready to go. One guy quoted closed cell in walls and roof. Another said he would do closed in walls and open cell on the roof, (I have no ceiling). He said open would show any roof leaks. Now confused on which way to go, any thoghts?

 

[dcg9381]

They're both great products. Open cell will absorb water and drip. Closed cell won't it'll distribute the drip to somewhere else and make the source pretty hard to find.

Neither is a factor if you've got a "seasoned" roof that you know doesn't leak.

Open cell is generally the better value in $ per R value. I'd use either... The application for closed cell (IMHO) is largely for tight spaces - like say a 2x4 wall where you need maximum insulation per inch.

 

[My Old Tools]

If you insulate the shop that well you will have no problem cooling it. Foam insulation is not required. My shop is 1200sf with 12' walls and a 6/12 pitch, 600sf of loft area. 22 feet to the peak. It is insulated with standard plastic backed roll fiberglass on all sides and roof. The roof then had an additional layer added with strapping. I can cool it as low as I want with a 36k MrCool. By as low as I want I mean you can hang meat if you want. We are hotter than Houston in Jul-Aug, and just as humid in June. (Tyler)

 

[Hobby_Man22]

Old tools, how does that insulation do as far as blocking noise going to the outside? Or vice versa. Is it nice and quiet inside?

 

[brianpgriset]

It’s pretty well known that I am not a fan of spray foam in metal buildings because of the potential for future damage. I like spray foam but just not applied to metal.
You should be discussing this with your building supplier. All your requirements can be met easily with fiberglass for a lot less money.
I will void any warranties for any of the buildings I sell if spray foam is applied at any point after we finish.

Never understood this. Metal roofs with both spray foam and fiberglass can leak. Fiberglass absorbs water like a sponge and makes a huge wet mess that will never dry out and has to be ripped out and replaced. A closed cell wouldnt absorb anything. Yes I guess it could channel but would soak in way less than fiberglass.

Wouldnt spray foam be better in any scenario?

This happened at a gym i went to, fiberglass insulation with a leaking roof. Huge mess, hard to find leak. Owner was on the roof all the time chasing them down. Replaced fiberglass multiple times.

To the OP i am in Baytown and am foaming directly to metal wall next week. Shop will be finished Friday. The builder I used said foam is very common and used regularly on the barndominiums they build.

 

[GTSDave]

To the OP i am in Baytown and am foaming directly to metal wall next week. Shop will be finished Friday. The builder I used said foam is very common and used regularly on the barndominiums they build.

brianpgriset, How did it turn out? Did you use open cell or closed cell foam? Did you use a local company? The quotes I have gotten for my 50x50 range from $5,600 to over 12k for the companies that bothered to call me back.... I am over in Ft Bend county.

-Dave

 

[Firebrick43]

Never understood this. Metal roofs with both spray foam and fiberglass can leak. Fiberglass absorbs water like a sponge and makes a huge wet mess that will never dry out and has to be ripped out and replaced. A closed cell wouldnt absorb anything. Yes I guess it could channel but would soak in way less than fiberglass.

Wouldnt spray foam be better in any scenario?

This happened at a gym i went to, fiberglass insulation with a leaking roof. Huge mess, hard to find leak. Owner was on the roof all the time chasing them down. Replaced fiberglass multiple times.

To the OP i am in Baytown and am foaming directly to metal wall next week. Shop will be finished Friday. The builder I used said foam is very common and used regularly on the barndominiums they build.

Closed cell spray foam will absorb water. Nearly every old boat that dosent get a dry storage space has satuated floatation foam. I have seen multiple cases of spray foam with signifcant damage and water satuation.

A friend had is pole barn spray foamed 11 years ago. A flashing detail allow water in one corner. After the steel panel started rusting through he pulled it off to find water satuation in large area and the laminated poles(4) and girts in the corner was rotted and all the metal was destroyed by rust or removal to fix.

Spray foam can not be applied consistantly enough to make sure its perfectly closed cell. Difference in temp or slight diff in mixing ratios and spray pressure/distance are all varibles hard to control.

Even cfc blown xps foam, which is the most water resistance will absorb 5-7 percent weight. But the biggest difference is lack of a drainage plane. Spray foam attached to a membrane or something leaves an air gap and doesnt allow for water to satuate and set against the metal rusting it and would be a grat system. The ribs on steel sheeting should never be filled.

As far as the gym roof leaks, no insualtion will deal with roof leaks. He needed to replace the roof. But i have seen fixed leaks over fiberglass dry out. Sounds like his were terrible leaks never fully fixed.

 

[Hobby_Man22]

I have most of the roof insulation done with r30 batts. Still have about 5ft to go on a 50ft span, it will hold it at 63 when it's 35 outside but does run the whole time. So idk. I'd prefer it to be 75 that way I can sit still with no jacket on and watch tv if want

 

[Hobby_Man22]

Maybe that's all i'm going to get out of it.

What do you guys think? 60,000 but heat pump system and it doesn't keep the shop warm enough? It runs the whole time, doesn't even cycle off. Should I call the a.c. guy back and see what he can do? I do see if it will be the same issue in the summer.