Flooring question (compressive strength of unframed foam boards)

banman

Bus Crazy

Join Date: Aug 2019

Location: Moved to Zealand!

Posts: 1,517

Year: 2002

Coachwork: Thomas

Chassis: Freightliner FS-65

Engine: 7.2L Cat 3126 turbo diesel

Rated Cap: 71 passenger 30,000 gvwr

Quote:

FatBoySTL

Originally Posted by

Foam Board Link

5/8" Sturd-I-Floor

I'm still on the fence on foam thickness (1"=R-6, 1.5"=R-9), but leaning toward the 1", then seeing how that goes. With ripping out the stock floor, that will have a minimal impact on headroom (also using 1" in walls, with 5/32" beadboard over it, with stub-outs off the chair rail for anchoring furniture).

Thanks, all. Based on the feedback, I think I've settled on the polyiso foam board, unframed, with a 5/8" tongue & groove Sturd-I-Floor. I was not aware that the insulation loses some properties in cold weather, but if it drops to something similar to the pink stuff, I don't think I'm any worse off for it. The bus will primarily be used in the desert southwest for the next few years.I'm still on the fence on foam thickness (1"=R-6, 1.5"=R-9), but leaning toward the 1", then seeing how that goes. With ripping out the stock floor, that will have a minimal impact on headroom (also using 1" in walls, with 5/32" beadboard over it, with stub-outs off the chair rail for anchoring furniture).

If you know your bus is well sealed I guess this is less an issue. I would still paint both sides and edges of the board (unless the top side is for show with no additional flooring) with any good house paint to seal the wood. Doesn't have to be exterior because no UV is involved -- oops-discount bathroom/kitchen paint would be a good deal...

The plywood you've picked is interior rated ply. It will not do well with any water leakage...If you know your bus is well sealed I guess this is less an issue. I would still paint both sides and edges of the board (unless the top side is for show with no additional flooring) with any good house paint to seal the wood. Doesn't have to be exterior because no UV is involved -- oops-discount bathroom/kitchen paint would be a good deal...

David

The Murder Bus

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