Insulating Steel Skin

[James Biddle]

We spray foamed our detached shop and the inspector told us to either cover it up with and approved fire rated barrier (drywall or equiv.) or to spray the foam with an intumescent paint. The walls were covered with T1-11, but we opted to spray the underside of the roof foam to keep the space as open as possible on the second floor.

[Tom Bender]

My experience with spray foam in industrial applications;

It seals very well
An inch is pretty good insulation
It covers everything including the framing and is not easy to smooth
It is not easy to apply an even coat so you will probably get an excess in most places but there is the risk of thin spots
Any overspray that drifts will adhere to everything and can not be removed. You would have to replace your glasses for example
It is ugly

[John Nordyke]

Thanks. I'm going to have 2 inches sprayed for R14 in the walls and cover with OSB or drywall. It's flame-resistant. As to the ceiling, with a pitched roof having foam sprayed on the interior side of the steel, what do I do with the ceiling? As someone else brought up, do I vent the "attic" space if applying additional insulation to the ceiling (10 ft ceiling, btw).

[Jim Becker]

John, the closed cell foam sprayed in our addition had a fire additive (turned it green) and our township didn't require it to be covered up in the attic rafters which despite being storage and HVAC, is considered "conditioned space" because of the insulation being on the envelope.

[Bill Dufour]

John, the closed cell foam sprayed in our addition had a fire additive (turned it green) and our township didn't require it to be covered up in the attic rafters.

My undestanding is that in storage space, not living space, the fire codes allow exposed insulation likme fiberglass which is flammable even with no kraft paper. I have not seen foil faced fiberglass for decades. That is aslo flammable. rockwool is the only truly nonflamable batt type insulation. Vermiculite and perlite maybe non flammable pour-able insulation, not sure though.
Bil l

[Jim Andrew]

Having your roofing insulated, and a ceiling insulated as well will save you money on your utilities. The type of insulation on your ceiling is not important, blow in cellulose is treated so it will not burn. If you blow in insulation, be sure to block the edges of the ceiling as the insulation can slide off into your overhang.

[Mike Heidrick]

John you getting wainscoting? Got a bit close to the building with the loader this weekend and am sure glad I had wainscoting. I also now see the value in wrapping the building and insulting on that. If it was spayed on the steel directly it would have been much more than the 5min it took to fix my mistake. FYI.

Mikie