Hi All, I've been lurking around for a while, and am working on installing a wood/pellet boiler system in an outbuilding. It's all coming along quite well, and I'll post an install thread once I get it up and running. I've converted a propane tank and have insulated between the tank and the wall with 6" of foam board in three layers (2.5" polyiso/1"XPS/2.5"XPS) with staggered seams. That was the easy part - now I need to build out the foam box into the room and one easy way I've thought about accomplishing this is to build some 2x4 framing next to the tank and use long screws to secure the foam boards to the 2x4 framing. This would put the 2x4 framing inside the storage tank insulation box, meaning the 2x4's are going to see the tank temperature. As of right now, I don't see the 2x4's touching the tank, they will just be inside the insulated space between tank and foam board Anyone see any problems with this, or with having foam board touching the storage tank? My inner layer of foam is 2.5" foil faced poiyiso. I guess I'm asking because both the x4s and the foam are quite flammable, and I'm just wondering what people think about this from a fire safety point of view. Other alternatives would be to use metal. I could easily fabricate up metal brackets and even weld them to the tank. But foam to framing fasteners are a bit more complicated using metal. Might use all thread rod welded to the bracing with nuts on the outside of the box? Just had another thought to use metal studs for the framing. maybe that would solve both problems?