fastmerc said

There are a number of DIY spray kits available....as close as Home Depot, probably Lowes. I got a catalog with my "spacer adhesive" from a place called J&R Products Inc. WOW is all I can say.....packed full of scrapers and shavers and blowers and everything that you'd want! Probably at full scale prices too.....

I don't know what the "material data sheets" say about installing this DIY spray directly on tin....but if science is real....and rust can't happen in the absence of air and water......well then spraying this directly on the tin would be OK! I just wonder about the temp of the tin in direct contact with the sun.....how well would the stuff handle this temp!? Pretty danged hot! But do some research and ask questions.

One thing about the fiber glass insulation is that it is bascially some fibers in a bag displacing air.....but not much....air is still in there.....and as we know air transfers temperatures..... or slows it down a little bit.

I'm suggesting that this type of "batting" insulation is a sort of stop gap measure. The plastic film on the rolls likely does the big job of stopping moisture movement..... The air amongst the fibers slows down the heat transfer but doesn't block it like closed cell (spray) foam or the ISO board mentioned above.

BUTT, putting this stuff up is still a wise choice before you move in!!!!
Shop looks nice!!!! I vaguely remember the day my shop was empty.......! :)

Steve

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72bluNblu said

Not off hand, it was through the building manufacturer I believe and I don’t think it’s called out by brand in the quote just its R value/thickness. I’ll take a look tomorrow when I’m home



The science is real, rust is oxidation and can’t occur if there’s no oxygen for the reaction.

But that doesn’t mean that any spray on foam will work directly on any metal. All of those metal building panels are painted/coated/galvanized, so whether or not it a particular foam is ok for that panel will depend on the chemical make up of the foam and the specific coating on the metal. And yeah, the foam would have to be able to withstand the temperatures of the metal panels or it would break down/separate.

Rust would also be a pretty minor concern, again, all of those panels are treated somehow and of course the outside of the panel is still exposed to air.



Uh, a closed air space is actually a VERY good insulator. It’s literally why insulation is made the way it is. Fiber fill sleeping bags and jackets work on the same principle. So do firefighting turnouts, they’re bulky to trap air because it provides additional insulation. The fact that the material won’t burn is only one part, because while the material won’t burn it still gets hot enough itself to burn the person wearing it.



Yes, the facing on the insulation is the vapor barrier, that’s literally how it’s designed.

Closed cell foam doesn’t “block” heat transfer any more than any other kind of insulation. It follows exactly the same thermodynamic process that any other insulation does. It has its own thermodynamic constant, and that combined with its thickness is how you calculate the energy transfer. It may be better or worse than other insulation types but it doesn’t “block” energy transfer.

There are benefits and drawbacks to both kinds, with the spray in insulation if you ever have to replace a panel, repair the building, repair the wiring or plumbing etc - good luck. Depending on the chemical make up of the foam it will also break down at some point, how long it lasts will depend on the chemical stability of the foam itself. Pros and cons for both, with the rolled insulation it’s a lot easier to install it during construction, afterwards makes it more time consuming.

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