Originally Posted by choochee
i have very little experience with this kind of work......
where did you staple the furring strips to the plywood? i could not see the holes? did they stay in place pretty easily when you put glue on them and then layed the plywood on top? seems kind of scary to do...like glue might go everywhere on the metal floor
then just bitu-tape and some padding? how is the padding attached?
haha! I have very little experience (none really) with camper van conversions as well, but I don't let that slow me down
Here is a slightly more detailed sequence...
We cut the 1/2" BB ply to fit in the van, around the wheel wells, etc. using the old carpet as a template trying to minimize the exposed seam(s) since they may telegraph through the vinyl floor which we haven't picked yet.
We ripped some 3/4" plywood into strips and laid them in the grooves on the floor. Since they were leftovers from another project, there are short pieces at each end and a few other places. One goal of this exercise for us is to burn up some of the leftover materials that we have hanging around the garage.
There are a few floor undulations that would require staggering the strips a bit, you just want enough to make the plywood stiff enough to not deflect under your feet. If you use a thicker, say 3/4" top deck you may be able to get away with less strips.
Once everything was cut and in it's happy place we tilted up the 1/2" decking ply and ran beads of PL 375 (liquid nails would work just fine also) along the furring strips, dropped the decking ply back down and shot 1" long pneumatic narrow crown staples through the deck ply into the strips every 5" or so, like nailing down a subfloor in your house. The staples only really hold the wood together while the adhesive sets up. You could skip the adhesive but you may end up with a squeaky floor.
The carpet padding is attached to the underside of the flooring with 3/8" long staples from a bostich hand stapler, similar to what you would use to attach felt paper to your roof or rosin paper to your floor during remodeling. I don't know how much insulation or sound damping we will get from this but it was a project leftover from something else.
The bituthane strips may or may not be needed, again, we are burning up old project leftovers when it seems like a good idea.
I am planning on installing 1/4-20 brass threaded inserts in the furring strips in a few locations where there are existing holes in the metal floor to fasten/locate the floor from under the van. That way there are no extra holes poked in the metal van floor. I imagine that you could use liquid nails type decking adhesive to glue the furring strips to the metal if you want. Future mods may be a PITA through.
In our case, 100% of the decking edges will be trimmed with something so that eases up the cosmetic accuracy requirement.
I contemplated rather heavily running 1/2" strips cross-wise on the floor, that should also work fine. The advantage to that is that there would be more space under the decking for insulation and running wires after the fact would be possible if you left some space for a wire chase under the floor. One downside of this method is that the finished floor would be over an inch above the metal floor. Running the 3/4" strips lengthwise, we will probably save 1/4" of floor height compared to crosswise strips.