I'm building a 12 x 16 x 12 high kiln. I have the structure but need to put in walls and insulation. Any advice on the material I should use?
I wood-framed with fibreglass insulation and ended up struggling for a while with vapour barriers.
I ended up tacking up Krona. (Other products of this type are usually polyethylene, which softens too much in the heat.) At first I couldn't find a tape that would seal it in the kiln environment. The 3M rep found me the stuff, though. 8951 is a tape for masking powdercoat or something, but it sticks tenaciously to the polyester surface of Krona and is unaffected by the heat and humidity.
You can get a guy to come in and blow polyurethane, which insulates and is a barrier too, but it costs a whack of dough.
I should add that, after foil tape failed on the Krona, I tried the Peel & Seal that Nyle sells. It is a 40 mil aluminum-faced asphaltic rubber made for low-slope roofing and such. It fell off the Krona, too. (Softens in the heat and pulls away.) Maybe it would seal other materials, but not the smooth polyester of Krona.