Insulate with closed cell spray foam directly against steel panels or against barrier

[bikesandcars]

I should have asked my 40 x 60 pole barn builder to Tyvek the walls. I was going to use r19 batts or 3" foam board inside the purlins for insulation. I am now leaning towards spray foam. I'm concerned about applying the foam directly to the panels in case I want to replace one ever.

My idea is to Tyvek inside purlins or use 1/4 xps fan fold to keep the spray foam off the panels. This also creates a 1.5" dead air space between posts and steel. I have rodent guard installed so there is a minimal air path behind the panels to the outside.

Any thoughts on how to handle this?

Pros to spray directly on panels:
Tighten panels up
Block all air infiltration
Less work now
Less cost now

Pros to installing barrier and spraying inside purlins:
Easy to remove panels
Inside of steel can breathe a little.

Thanks!


Sent from my XT1585 using Tapatalk

 

[My Old Tools]

When would you want to remove panels? I never have. You can cut foam with a knife if you do need to, then foam it back in place. Will foam adhere well to Tyvek? Will it leave a place to sweat?

 

[theoldwizard1]

Spray foam 1-2" thick, then fiberglass roll or batts.

 

[terryo1965]

The guy who did my spray foam wouldn't spray against Tyvek, he tore it all out. I didn't question it, but he did an awesome job and I love it. I think it was the best money I spent building the barn.

 

[bikesandcars]

Thanks folks... Looks like 3 votes for directly on and none for a baffle. I appreciate the feedback. When would I remove a panel? I hope never again. I hit one last week moving stone and had to

Sent from my XT1585 using Tapatalk

 

[BadgerBoilerMN]

What does tyvek do for you?

It is very hard to properly foam the inside of the corrugated steel. Any air pockets may leave you with condensing moisture. Rust from the inside out. It will also eliminate the natural convection, which can keep you cooler if you insulate the inside properly.

I used Thermax to on the purlins to create a proper air and radiant barrier then blew fiberglass to the inside wall.

 

[Jess]

The benefit of Tyvek or a similar building wrap is to separate the metal sheathing from the spray foam inside. In the event you need to replace a panel or open it up to do changes, the foam isn't on the metal. Since its built, it would be pretty easy to put something on the inside. The spray foam will be the air barrier, so the Tyvek is really overkill.

 

[bikesandcars]

In my case the Tyvek is just a physical barrier between spray foam and panels. I could use plywood, luan, 1/4 xps fan fold, other foam boards, landscape fabric, thermax, etc.

Thermax brings up a good point though, it could help in summer reflecting heat out. I'll cost some out

Sent from my XT1585 using Tapatalk

 

[SALIV8]

My GC advised to use tyvek because when a panel gets damaged, if it ever gets damaged and needs replacement, it will be quite difficult to replace if there is spray foam without a barrier.

 

[BadgerBoilerMN]

Rigid foam goes on the perlins and fiberglass inside with finish panel inside. There is little advantage to spray foam in this application.

I foamed my own 1921 farm house, including a hot roof, but the extra room in the pole shed left plenty for lower cost/per/R-value inch options.

 

[CooperFarm]

I considered spray foam in a 26x38 pole barn, but the cost was exorbitant and the risk was not worth it to me personally. I don't like the idea of spray foam directly on steel panels for a couple of reasons. First, call me paranoid, but if there is ever a failure with the hardware, especially on a roof panel, and you have moisture infiltration you will never know it until it is too late. Perhaps a long shot, but why take the risk. Secondly, and maybe more importantly, you run the risk of voiding the warranty on the steel panels. It is a grey area as far as the warranty is concerned, and from my research the manufacturer will likely find a reason to not cover steel that has been foamed. It was recommended (by a pole barn builder/professional) that if I wanted to use spray foam to install interior baffles (lauan ply or the like) on top of purlins between posts and spray on top of that, creating a 1.5" air gap and eliminating the risk of spraying directly to the steel.

 

[bikesandcars]

I like the luan idea, cheap and can be stapled/glued to purlins for a solid bond to both purlins and spray foam

Sent from my XT1585 using Tapatalk

 

[Jo Diesel]

What if you cut 1 1/2" foam board and put it in between the perlins and then spry foam over that.

 

[HunterDan]

I'm in the same boat, and posted a thread recently. Will sub to this for ideas

 

[bikesandcars]

I like the insulation idea. Right now fan fold is winning for me

Sent from my XT1585 using Tapatalk

 

[bikesandcars]

Decided to go the OSB route. Right now I'm glad I did, it is stiffening the structure up nicely and is easy to nail up. Using a siding nailer and construction adhesive.

Sent from my XT1585 using Tapatalk

 

[bikesandcars]

 

[Randy in Maine]

Since you are going that way...

When I converted my single car garage into a heated room, I used 1.5" and 2" rigid foam to fill up the 2x4 framing (5.5" on the ceiling). I used those spray foam cans to fill in the voids. It works OK but cost just as much as the spray foam would have and was far more labor. Not as tight as spray foam but good enough.

 

[bikesandcars]

Thanks! I could do R15 for 50 a sheet, that's 3500. R14 spray foam was 4k installed. I'm happy to do the work with the OSB even though it added $700 because it seems like it will be a good system

Sent from my XT1585 using Tapatalk

 

[HunterDan]

Looks great! Are you gonna do the roof to? If I go this route, I may do the 3/4" foam board on the roof just for ease of hanging, much lighter than trying to do 4x8 sheets of Osb 20' off the floor

Also, What are you doing as far as electric? Emt on the finished wall?

 

[Rocker4x4]

I was told NEVER spray foam against metal! Mine is stick built so I cut 1/2 closed foam board and nailed inside of 2x6, that left a air gap moisture barrier between metal. I then use wet cellulose due to fire resistance. Even larger pole barn builders like Morton will not warranty any metal that had foam sprayed to the metal because of moisture issue. They clam it will rust metal from inside out

 

[bikesandcars]

Looks great! Are you gonna do the roof to? If I go this route, I may do the 3/4" foam board on the roof just for ease of hanging, much lighter than trying to do 4x8 sheets of Osb 20' off the floor

Also, What are you doing as far as electric? Emt on the finished wall?

Ceiling will be metal with fiberglass blown in. Having my pole barn contractor do it as I have 13 ft ceilings, a busy job and no helpers. My buddies (and me) all have kids!

Sent from my XT1585 using Tapatalk

 

[bikesandcars]

I was told NEVER spray foam against metal! Mine is stick built so I cut 1/2 closed foam board and nailed inside of 2x6, that left a air gap moisture barrier between metal. I then use wet cellulose due to fire resistance. Even larger pole barn builders like Morton will not warranty any metal that had foam sprayed to the metal because of moisture issue. They clam it will rust metal from inside out

Makes sense to me, I don't like the idea of directly on. I DO like the idea of a 1.5" air space that breathes but blocks the direct impact of the wind. The OSB has really stiffened the walls up.

I'm also capping the carrier's and gable end walls with OSB and putting 2" foam board in the gap. My spray foam guy will over spray them giving me r24 foam in the wall caps

Sent from my XT1585 using Tapatalk

 

[HunterDan]

What are you doing with electric?

 

[bikesandcars]

What are you doing with electric?

Running wires after spray foam.

 

[bikesandcars]

Good enough for winter.

 

[Jeepster04]

That looks beautiful. I bet that thing is heated just by body heat!

 

[Randy in Maine]

What ceiling panels are those? My buddy (a welder) is looking for something like that for the inside of his new welding shop.

 

[bikesandcars]

What ceiling panels are those? My buddy (a welder) is looking for something like that for the inside of his new welding shop.

Those are steel interior panels. They look like exterior panels, but since they are made for interior and don't have to survive the elements they have no warranty and are cheaper.

Mine came from a local mnfr

Sent from my XT1585 using Tapatalk

 

[bikesandcars]

That looks beautiful. I bet that thing is heated just by body heat!

Not bad, see my related ceiling post. Since I have some gaps at doors and no vapor barrier in ceiling I think I still have some slight air movement.

Eastern PA, I have a 5000 btu 120v auxiliary room heater is keeping it 55/60. I have a turbo heater set to come on at 50 and it doesn't.

It's a 40 x 64 building with 13' ceilings. My estimated heat load was 44,000 btu. I seem to be beating that. It's also almost empty which hurts swing temps.

Heater I use: http://www.tractorsupply.com/tsc/pr...tower-power-heater-and-fan-with-walnut-finish

 

[bikesandcars]

My feedback spraying on OSB is that the structure is pretty solid and blocks noise well. The contractor needed to replace some windows and the job was easy without foam on the panels. Overall I am very happy now that I spent the time to do it right.

Sent from my XT1585 using Tapatalk

 

[lakeroadster]

Looking good Randy.

When would you want to remove panels? I never have. You can cut foam with a knife if you do need to, then foam it back in place. Will foam adhere well to Tyvek? Will it leave a place to sweat?

How does one "cut foam with a knife" after the interior of the wall is finished?