Spray foam gone bad

[skippydoo]

I had a 30x40 built a year ago and had the walls and roof sprayed with closed cell foam. I had the walls wrapped with tyvek and the roof was supposed to be too, but wound up being lined with a underlayment from a company in PA I believe called Levi's. I noticed after the first snow fall a few spots on the roof were melted , then about a month later more spots. I then got my Radiant heet hooked up in March and blew thru 100 gallons of propane. I decided to pull a ceiling panel down and was shocked. The foam had shrunk and pull away from several of the truss's. Fast forward to now and almost half of truss's are that way . 3'' of foam was applied. The guy is going to make good for the issue. They are seeing issues when applying foam to tyvek and anything thats very smooth . They are also removing anything smooth from now on before they spray. Posting this so no one else has problems.

 

[jkeyser14]

Tyvek is expanded PTFE (Teflon). Almost nothing sticks to it. I am not surprised the foam is falling off.

 

[Earp69]

The insulation company I just talked to told me they prefer to spray over house wrap because if you ever have to pull a panel you can do it without destroying the metal. This is strange, my barn is going up next month, I'd like to get to the bottom of this before mine goes up.

 

[yeldogt]

I'm confused ? You had the tyvek install under the roof deck and wall sheathing ?

Some foams can shrink if the mix is wrong -- temp -- applied too thick. That's why it's typically done in layers as it's applied.

 

[woody6904]

Has anyone tried spraying foam up against Typar instead of Tyvec? Wondering if it would stick better.

 

[NUTTSGT]

Did you just take pictures through the hole or did you actually climb over to the problem areas ?


I'm curious if the spray foam is actually pulling away or the tyvek has ripped away from where it was attached ?


Me personally, I would have put the Tyvek on the bottom chord of the trusses, screwed up the metal and then spray foamed the attic side of the ceiling. I don't need an attic space that is conditioned to have the bottom of the roof deck foamed.

 

[bigdav160]

Not my specialty but I have never seen foam applied that way

 

[Dzlpete]

That setup is all wrong. Foam should be applied to backside of sheathing, not a fabric or tyvek type sheeting.

 

[yeldogt]

Is this a pole building ? I ask because -- have never built one and they do seem to have some crazy (IMO) things going on when people take what is a utility structure and try an make something else.

Was this an exposed (underside) metal roof -- sprayed?

 

[homebuilt burner]

It looks to me that when they built the building, the bottom of the steel roof (which has the tyvek) was spray foamed then they put the steel ceiling in. It would be difficult to be in the crawl space and spraying foam onto the top side of the ceiling, even though that would be the prefered way. To spray the under side of the roof should not have been an issue. My shop has a steel roof and under the steel is the bubble foil product. It is supposed to be insulation but not really, it is used as more of a vapor barrier to keep condensation off of the bottom of the steel.

I think the best way would have been to have an underlayment on the bottom of the roof steel, then to build a false ceiling spray foam against that, and then install the visible ceiling, but that is extra work. This should have worked fine but due to the foam not sticking now there is a problem.

It sounds like the OP's foam guy is stepping up to make it right. It is a good cautionary notice to anyone building going forward. Good Luck to the OP and the rest of us will take note.

 

[Jeepster04]

Did you just take pictures through the hole or did you actually climb over to the problem areas ?


I'm curious if the spray foam is actually pulling away or the tyvek has ripped away from where it was attached ?


Me personally, I would have put the Tyvek on the bottom chord of the trusses, screwed up the metal and then spray foamed the attic side of the ceiling. I don't need an attic space that is conditioned to have the bottom of the roof deck foamed.

I would also like to know if it pulled away from the tyvek or pulled it down with it.

 

[skippydoo]

I'm confused ? You had the tyvek install under the roof deck and wall sheathing ?

Some foams can shrink if the mix is wrong -- temp -- applied too thick. That's why it's typically done in layers as it's applied.

Tyvek on walls only, Levi's roloshield underlayment under the metal roof.

 

[skippydoo]

Couple of pics before foam