Shop/garage insulation plan?

[jeff77indy]

This most likely a rehash but I'd like to see if this sounds feasible.

My shop/garage is a 40' X 48' x 11' pole type building with metal siding and roof. Side wall post and trusses are 8' centers.
What my plans for insulating the walls is to place 1 1/2" foam board type insulation with the slick side towards the metal cut to fit between the wall purlins with either fan fold or 1/2" insulation board on the interior face of the purlins covered with 7/16" OSB. Don't really want to stud the walls out flush between the post.
For the ceiling, I plan on building a 2' on center grid between the bottom cord of the trusses with 2"x4" and 2"x6" material to attach either corrugated ceiling metal or the flame proof poly corrugated ceiling material then add blown or roll insulation above that. Where the 2"x6" grid is I plan on decking this for storing light weight items.
The overhead doors I plan on either gluing in the foam board type insulation or using the roll type bubble/foam insulation.
I'm not looking to run around in my shop in a tank top and shorts in the middle of winter just to be comfy.
I heat with a wood stove but may purchase a heater burning fuel oil or diesel possibly electric to get it warmed up while the stove is catching up.

Thanks for any help.
Jeff

 

[rodnok1]

Sounds like a good plan to me. I would consider adding a vapor barrier to the ceiling at least to keep the insulation dry. Some people have used non vented aluminum soffit material for ceiling.

 

[Dragster Racer]

I would not suggest only insulating between the purlins on the walls....however.
It sounds like you are not heating this all the time. If this is the case, your plan is perfect, fast and effective. You just want to slow the heat loss, and create a thermal break. It is similar to my old garage. I say go for it.

 

[Busted_Knuckles]

Might want to think about a vapor barrier in there somewhere, and I would not put the rigid insulation flush against the exterior wall tin, for you might have a condensation problem, and long term rusting. Id at least fir it out 1/4" or more.

If you're using OSB on the walls, you might want to hold it up off the floor at least a 1/2" and trim it out with non-flammable base, so if your welding or cutting, and a hot ember makes it to the edge of the wall.....(no fire) if you search the site (google usually works better than the GJ search tool), you will find allot of warnings about OSB in garages, not usually a good idea...I know I wont be using it. They do make a thin interior tin for ceilings and walls too, not everyone knows that.

I'm getting ready to do the same as you, Ive got an 50 x 100 that is wide open and I need to close in. Ive been trolling the site looking for ideas too...

 

[jeff77indy]

Thanks for the input.

Does anyone have info on the thin interior metal panels for ceiling and wall use? Would all metal suppliers have this or just certain ones? I have a number of vendors for metal siding and roofing in this area as most out buildings are of pole construction here.

How would a person go about installing a vapor barrier in the walls since the siding is already on? The ceiling won't be a problem.

Thanks
Jeff

 

[Dragster Racer]

Vapor barrier goes to the inside anyhow. So you are in good shape if the exterior siding is already on.
I got some interior tin at Menards. I balked for a long time about the cost vs osb, so I did my ceiling osb. I caught a sale at Menards, and by the time you figure paint costs in, the white tin was not measurably more expensive. I have done one wall in it, and it goes so slick! You order it cut to the correct length, and you can really cover a lot of acerage with one set of helper hands. I have two other walls I will be doing with it.

 

[jeff77indy]

So I am back onto this project again, should I space the insulation out from the metal siding or will it matter?
What is the difference between the foam insulation board and the vinyl wrapped fiberglass batts used in metal framed buildings being in contact with the siding?
My plan is 1 1/2" foam sheets cut to fit between the horizontial purlins then possibly 1/2" or fan fold foam insulation over that and the purlins follwed by a plastic vapor barrier with osb on top of that for the walls.
The ceiling will be a frame work of 2"x4" and 2"x6" lumber on 24" centers with a plastic vapor barrier then either metal or a plastic with fiberglass batt insulation in the attic.

 

[mobetta]

interior liner panels.(barn steel for inside)

have you considered just attaching 1.5" foam to the purlins? it would be way easier, and no thermal break at each purlin. foam around them, caulk and tape the seams, no VB needed. you could screw drywall or liner panels thru the foam w/ long enough screws.

 

[jeff77indy]

interior liner panels.(barn steel for inside)

have you considered just attaching 1.5" foam to the purlins? it would be way easier, and no thermal break at each purlin. foam around them, caulk and tape the seams, no VB needed. you could screw drywall or liner panels thru the foam w/ long enough screws.

I was thinking on that very same idea today.

 

[kywildcat]

Might want to think about a vapor barrier in there somewhere, and I would not put the rigid insulation flush against the exterior wall tin, for you might have a condensation problem, and long term rusting. Id at least fir it out 1/4" or more.

If you're using OSB on the walls, you might want to hold it up off the floor at least a 1/2" and trim it out with non-flammable base, so if your welding or cutting, and a hot ember makes it to the edge of the wall.....(no fire) if you search the site (google usually works better than the GJ search tool), you will find allot of warnings about OSB in garages, not usually a good idea...I know I wont be using it. They do make a thin interior tin for ceilings and walls too, not everyone knows that.

I'm getting ready to do the same as you, Ive got an 50 x 100 that is wide open and I need to close in. Ive been trolling the site looking for ideas too...

I'm using OSB on my garage walls, and I'm going to lay a treated 2x4 on the floor to keep the OSB off the floor, and have a little room to spray the floor off if needed for cleaning purposes.

 

[steves shop]

Any updates on this project? I am watching this one to see if you put the rigid foam between the girts or run it over them.

 

[creativecars]

I want to put insulation between my metal studs, but was thinking about how cold metal is. Would it be a good idea to put a layer of something (foam board?) over the studs also, before some sheetrock or OSB? Just a thought.

 

[toyotadriver]

I'm about to do this same thing. Anyone have pics of it? I'm going to put the foam sheets on and then install reflective foil over it. Then the metal.

 

[stingry]

I'm about to do this same thing. Anyone have pics of it? I'm going to put the foam sheets on and then install reflective foil over it. Then the metal.

Here ya go:

View media item 7715
2x6 conventional framing with 2x4 girts. The 1 1/2 in insulation is a product from Menards called R-TEC. It has a reflective coating on one side. I put this to the outside to act as a radiant barrier. The tin went directly over the foam. I see no need for any airspace between the two. For condensation to form you need moisture-laden air to condense moisture on the tin. This eliminates that. The R-TEC has an R Value of about 7.

Cheers
Steve

 

[toyotadriver]

Here ya go:


2x6 conventional framing with 2x4 girts. The 1 1/2 in insulation is a product from Menards called R-TEC. It has a reflective coating on one side. I put this to the outside to act as a radiant barrier. The tin went directly over the foam. I see no need for any airspace between the two. For condensation to form you need moisture-laden air to condense moisture on the tin. This eliminates that. The R-TEC has an R Value of about 7.

Cheers
Steve

Thanks. How much were the sheets?

I'm pricing some 4x8 sheets for $17 per sheet. Closed cell foam. R5 per inch. R7.5 for the 1.5 inch sheets.

 

[dlenkewich]

Maybe it's not on your list of concern, but, the problem is the cost.

You could frame out your walls (with 2x6) and put in an R-19/20 batt for likely half or 2/3rd's the cost of putting in one layer of rigid foam board, and you'll get a lot more insulation for your money.

 

[toyotadriver]

Maybe it's not on your list of concern, but, the problem is the cost.

You could frame out your walls (with 2x6) and put in an R-19/20 batt for likely half or 2/3rd's the cost of putting in one layer of rigid foam board, and you'll get a lot more insulation for your money.

The thing is, R values really aren't all that accurate. R5 of foam insulation will be much better than R5 of fiberglass. Foam stops or at least dramatically slows the movement of air. Fiberglass does not.

I just bought 82 sheets of 1.5 inch closed cell foam insulation. With a 10% discount I paid $1350 for it all. Should need about 75 sheets for my 30x40 building but have some extras for waste.

 

[rburke65]

Here I thought R-5 was R-5! It's all the ability to resist heat flow. One type of insulation maybe thicker or thinner, but if the R value is the same they should insulate equally. Hey, I'm just the electrician.....what the hell do I know!

 

[dlenkewich]

This is where the foam producers try and confuse people.

They slander fibreglass by saying things similiar to what Toyotadriver, when, in fact you also have to take into account the vapour barrier/kraft backing that is used in with fibreglass insulation in any thermal senario - The only time you do not use a vapour barrier/retarder with fibreglass is in an acoustic situation. You should ALWAYS be using some form of vapour retarder/barrier when using fibreglass, cellulose or mineral wool for thermal application.

Up here we don't use kraft back batts, we use straight fibreglass and we caulk all joints, cracks and seal with a rubber, flexible sealant called acoustical sealant and lay a full 6 mill vapour barrier and tape polypans around electrical and caulk or foam around all wires or pipes coming through the 'warm' side out to the 'cold' side. The local spray foam company's ad on the radio claims "Foam stops airflow unlike typical pink (fibreglass) insulation." - They are right, fibreglass doesn't stop airflow, but the sealed vapour barrier(building standard in our region) does. You have to be careful on what you take as fact.

"R-value" is a essentially a numeric scale of thermal resistance. If the product says R-5, wether it's foam, fibreglass, cellulose, etc, if it's installed correctly, it's R-5.

 

[stingry]

Thanks. How much were the sheets?

I'm pricing some 4x8 sheets for $17 per sheet. Closed cell foam. R5 per inch. R7.5 for the 1.5 inch sheets.

I bought them on sale at Menards for $12.99/sheet for 1 1/2". I will also be using R19 batts for a combined R value of approx. 26

 

[toyotadriver]

Actually, R values are a very inaccurate method of measuring the value of an insulation. Think of it this way. If it's cold outside but very still air, you can wear a fleece jacket and feel nice and warm. Now, raise the temp but add wind to it, and you're gonna feel cold.

But, the fleece jacket is the exact same level of insulation why do you feel cold even though the temp is warmer? Well, because the wind is blowing right through the fleece and you are losing heat quicker than when there was no wind.

Now, while wearing that fleece jacket, cover it with a light windbreaker. Now you're back to feeling warm again.

Try wearing a windbreaker covered with the fleece. Will you be warm? Well, probably warmer than wearing just the fleece but not much. Why? Well that fleece isn't holding in heat...the wind is blowing right through it. But, the windbreaker is stopping the wind reaching your body so you still are loosing heat...just not as quickly.

Fiberglass doesn't do a good job of stopping the flow of air just like that fleece jacket without a windbreaker. Putting the vapor barrier on the inside (while certainly needed for other reasons in your cold climate), is like wearing your windbreaker covered with a fleece.

Foam insulates the same regardless of whether it's wet or dry, windy or still. Fiberglass changes depending on the weather conditions. Under ideal conditions, fiberglass works fine. However, since things are rarely ideal, there are far better insulation choices than fiberglass...especially in extreme environments. In more mild climates, the increased costs of foam may not pay for itself. In extreme climates, the increased costs of foam may well pay for itself in a very short time.

R5 is R5...assuming that the environmental conditions are perfect. Change the conditions and R5 of one type of insulation will NOT be the same as R5 of a different type of insulation.

 

[dlenkewich]

Actually, R values are a very inaccurate method of measuring the value of an insulation. Think of it this way. If it's cold outside but very still air, you can wear a fleece jacket and feel nice and warm. Now, raise the temp but add wind to it, and you're gonna feel cold.

But, the fleece jacket is the exact same level of insulation why do you feel cold even though the temp is warmer? Well, because the wind is blowing right through the fleece and you are losing heat quicker than when there was no wind.

Now, while wearing that fleece jacket, cover it with a light windbreaker. Now you're back to feeling warm again.

Try wearing a windbreaker covered with the fleece. Will you be warm? Well, probably warmer than wearing just the fleece but not much. Why? Well that fleece isn't holding in heat...the wind is blowing right through it. But, the windbreaker is stopping the wind reaching your body so you still are loosing heat...just not as quickly.

Fiberglass doesn't do a good job of stopping the flow of air just like that fleece jacket without a windbreaker. Putting the vapor barrier on the inside (while certainly needed for other reasons in your cold climate), is like wearing your windbreaker covered with a fleece.

Foam insulates the same regardless of whether it's wet or dry, windy or still. Fiberglass changes depending on the weather conditions. Under ideal conditions, fiberglass works fine. However, since things are rarely ideal, there are far better insulation choices than fiberglass...especially in extreme environments. In more mild climates, the increased costs of foam may not pay for itself. In extreme climates, the increased costs of foam may well pay for itself in a very short time.

R5 is R5...assuming that the environmental conditions are perfect. Change the conditions and R5 of one type of insulation will NOT be the same as R5 of a different type of insulation.

Interesting view. If we left Insulation exposed on the exterior of houses your logic might proove something.

Put your windbreaker on, then your fleece(You'll need to pick the fleece that meet's the R-Value recommendations set out by your regions minimum code requirements). Now go back and seal your windbreaker with acoustical caulking and tape and seal any penetrations or cracks(Zippers, pockets, draw strings). Now sheet over your fleece with 3/8's plywood and your choice of siding or stucco.

If you seal your building envelope properly, it doesn't matter how windy it is outside. Regarldess of your insulation material, you loose your heat out your roof primarily and air can and will infiltrate through even the most effecient windows and doors.

Fibreglass actually insulates by have thousands of layers per batt which creates millions of air pockets to allow a temperature differential or a thermal break much the same way foam has millions of tiny bubbles which do the same job. No, fibreglass doesn't stop wind, but the siding on the exterior of your home does.

If foam was as great as everyone believes, by the "foam logic"(I'll call it), you wouldn't need a furnace anymore, the residual heat from the people, furniture and appliances would be enough to heat your home.

 

[dlenkewich]

Anyways, going back to the actual topic at hand:

My point was that it's not very money wise to pay moreto put less in the walls.

If it was going to be cheaper to go with R-5 foam board then frame it out and put in an R-20, then it might make a little bit of sense. But to pay more to put foam board in, you loose money there, and it's going to take longer to heat the building up and more energy to keep the tempurature up.

You could even save more money by framing the walls 24" O.C. and using wider batts.

 

[camilla_thomas]

I would not suggest only insulating between the purlins on the walls....however.
It sounds like you are not heating this all the time. If this is the case, your plan is perfect, fast and effective. You just want to slow the heat loss, and create a thermal break. It is similar to my old garage. I say go for it.

I completely agree with you..

 

[toyotadriver]

Here's what I ended up doing. R7.5 closed cell foam in the ceiling and the walls.

 

[ChuckD035]

I am about to go this route in my shop. Are we sure that moisture will not get trapped between the foam and metal or do the ribs provide adequate airflow to keep the moisture in check? I would hate to end up finding rust behind the walls.

 

[aventino68]

I am about to go this route in my shop. Are we sure that moisture will not get trapped between the foam and metal or do the ribs provide adequate airflow to keep the moisture in check? I would hate to end up finding rust behind the walls.

Thats what I wonder, I'm running rolls of batts or Rockwool in two layers at 90 degrees to each other. The build plans have the frame inset from the edges of the floor and a set of Z brackets that attach to the frame and then have the steel siding attach to them. So in theory with insulation attached to frame this leaves maybe 1" or so gap depending on the insulation I use. So I get airflow between the inside wall of the steel siding and the insulation? So condensation now isn't an issue? Seems like there's a lot going on climate wise in a steel building.

 

[earlybirds]

I used 1-1/2 inch XPS(pink) foam sheets between the girts on my walls in my 30x40x12 shop. I added a second layer of the same insulation over the first layer to cover the girts and add more insulation(now r 15) total. I used 5/8 inch plywood for the wall covering.

No wall sweating as mentioned above because the ribs on the exterior sheet metal siding provide adequate ventilation.