Originally Posted by nat_ster
You my fellow skoolie need to lean about thermal transfer and proper thermal breaks before giving advice.
A 2x4 has massive thermal transfer, but the screws have far more.
That's why Jake C left is floor "Floating", with no screws from the surface to the metal floor.
Sorry Nat Ster, I'm not an overly educated man. Nor do I have a degree in thermo dynamics, engineering, or physics.
What I do have is 25yrs exp in construction and a good deal of common sense. People on this site seem to get "wrapped around the axle" about stuff that doesn't really matter. In the end do what makes sense. To me notching the floor for the lower wall stud to sit directly on the bus floor makes sense but to each his own.
But according to the posters info, 1" insulation and 1/2" plywood. I can only assume it's hard board insulation and if it's Rtech then it really wont matter. If it's higher quality Rtech then the difference will be larger but I still doubt it will be noticeable.
1/2 plywood .63
R value of a 2x4=R4.38
So his floor is probably R4.48. 2x4 Lumber is R4.38 or a difference of R0.10.
ColoradoENERGY.org - R-Value Table