Planning access through the subfloor

[karrlot]

I am going to be installing my subfloor soon. I have osphoed, cut rust, painted the floor with rustoleum.

My tentative plan for a floating floor:

1) Put down red rosin paper.
2) Layout 2x4s on the edges and where the plywood seams will be.
3) Put 1 1/2" pink insulation board between the 2 x 4's.
4) Put down 1/2" plywood using liquid nails to attach it to the 2x 4s.

Here are my questions:

Is 1/2" plywood thick enough?

Do I need to put more 2x4s to support the floor or is it adequate to just have them at the edges of the plywood?

Do I need to frame 2 x 4s around the holes for toilet flange (going to a black tank under the bus), shower drain, and the fuel sending unit so the edge of the plywood is supported?

Do I need to have all of my cabinets, bunks, couch planned and put 2x4s under the plywood so they have adequate support?

Can I mount my passenger seats (which are still unknown) through the plywood and insulation and have them bolted into the metal floor or do I have to have them planned before I put down my subfloor?

TIA for any help.

[2martins]

Originally Posted by karrlot

I am going to be installing my subfloor soon. I have osphoed, cut rust, painted the floor with rustoleum.

My tentative plan for a floating floor:

1) Put down red rosin paper.
2) Layout 2x4s on the edges and where the plywood seams will be.
3) Put 1 1/2" pink insulation board between the 2 x 4's.
4) Put down 1/2" plywood using liquid nails to attach it to the 2x 4s.

Here are my questions:

Is 1/2" plywood thick enough?

Do I need to put more 2x4s to support the floor or is it adequate to just have them at the edges of the plywood?

Do I need to frame 2 x 4s around the holes for toilet flange (going to a black tank under the bus), shower drain, and the fuel sending unit so the edge of the plywood is supported?

Do I need to have all of my cabinets, bunks, couch planned and put 2x4s under the plywood so they have adequate support?

Can I mount my passenger seats (which are still unknown) through the plywood and insulation and have them bolted into the metal floor or do I have to have them planned before I put down my subfloor?

TIA for any help.

You don't need any 2×4s at all. I have 2" rigid foam with 1/2" plywood. Other people use 1" foam and 3/4 plywood. It is good. Even stopped the oil canning that was happening when we walked a couple of places in the bus and it's not even glued down.