Uneven floors... Leveling compound?

[posplayr]

Originally Posted by 1der

Posplayr's recommendation for the bed rug is a really good one. No need for "battens" or fillers in the grooves, still air is a fantastic insulator.

For clarity, never lay any aluminumized material directly onto the van metal floor. Any moisture that gets in there (and it will) creates an electrolysis that will eat through the floor paint and into the metal. Rust will then eat away at the exposed metal.

And regarding bolting/screwing the plywood floor to the metal floor - remember every fastener is a potential sound and thermal conduit. Additionally, the rigs flex and twist. A plywood floor that is bolted to the metal floor will be unable to flex. A cabinet that is fastened to both the walls and a hard fastened to the hard fastened floor will have to take all of the stress and flex which in time will cause the cabinets to squeak or loosen.

1der, thanks for sharing your experience and insight.

I had planned on only bolting down the 3/4" ply using the existing seat mounts. My XLT EB has provision for the standard rows of seating providing ample number of locations to hold down the floor. I would not plan on cranking down the bots as it would just warp the floor and compress the van rug and rigid foam underneath. So red Loctite on the bolt would secure the ply well enough needing only a firm (e.g. 10 ft-lbs) torque.

This would approximate your "floating floor" if using only 4-6 loosely bolted 3/4 Ply on top of the rubber mat and foam.

As far as screwing in cabinets, I would not screw all the way through the metal floor which is why i would prefer and recommend 3/4' ply (vs 1/2").

Another point I should reinforce about the radiant barrier, foam and other such non-metallic insulation do not reflect heat, it only slows heat transfer. So whether keeping the heat in or keeping it out, the radiant barrier refects a relatively high percentage of heat.

As 1der has mentioned you don't want to put a radiant barrier against a metal floor (or the wall) because of electrolysis. However, there is no benefit in the first place. The metal floor/wall will conduct heat right into the radiant barrier nullifying any potential reflective benefit.

With a double layer of insulative flooring, you can get two radiant barriers (separated by insulation) creating a multiplicative effect of stopping heat flow (e.g. double-layer heat transfer coefficients 0.2*0.2=0.04 vs 0.2 for a single layer).

https://www.ecofoil.com/pages/how-do...20a%20building.

[posplayr]

Originally Posted by kbeefy

I had seen the bedrug before... does it actually add any R value? I wasn't planning on using any battens on the floor, but just let the foam bridge the floor ridges. Maybe some butyl sound deadening in the troughs, though I think in that area it's probably a waste of time. If the bedrug is beneficial that would make things easier.


I had planned on gluing the poly to the floor and the gluing the subfloor to that, using PL300. I assume the bedrug would not fit well with that plan? Will the PL300 stick to rubber as well?

While i don't have a number for the rubber foam rug bed (different to the carpet), foam rubber probably has a higher R value(per inch) than rigid foam and will certainly have better sounddeading properties.

https://www.google.com/search?q=R+va...hrome&ie=UTF-8

The 1/2 Ridgid board I mentioned before is R1.93 which if using 1" is closer to R=4.

1/2 in. x 48 in. x 8 ft. R-1.93 EPS Rigid Foam Board Insulation

The bed rug varies in thickness between 5/8" with foam ridges and just under 1/2" on tops. No reason to even glue it or the rigid foam down assuming you have 3/4" ply and 4-6 through bolts for the whole thing.

If you are not going to have any bolts through the plywood to mounting brackets below the floor, the bed rug rubber mat might be a problem, but less so than relying on adhesives to keep the whole ply floor down in a roll over event.

[1der]

Originally Posted by kbeefy

...... Maybe some butyl sound deadening in the troughs, though I think in that area it's probably a waste of time. If the bedrug is beneficial that would make things easier.


I had planned on gluing the poly to the floor and the gluing the subfloor to that, using PL300. I assume the bedrug would not fit well with that plan? Will the PL300 stick to rubber as well?

Sound deadening is already provided by the mass of the bed rug and plywood. The butyl adds nothing but weight in to that construct. Use the butyl type deadners on surfaces that have little mass added like inside of doors, roof, walls, wheel arches, firewall, etc.

I glue nothing to the interior metal. A water leak/spill may necessitate removal of an entire interior to get it to dry out. Anything glued to the metal will be a nightmare to remove.

Paint the entire floor front to back and up the sides a couple of inches with POR 15 or similar to provide a water resistant surface under the first layer. Be careful around the bolts that hold the body to the frame. Best not to use POR15 on those but still paint them with something to seal them. Fill all holes in the floor with a sealant. Be sure to check all sheet metal joining surfaces to make sure you cannot see light through them.

Use the bed rug as a template for cutting your plywood pieces and keep any seams under cabinets or seats where possible. Use Of Simpson 4x6 tie plates holds the plywood pieces together horizontally. Use biscuits- not glued in -to eliminate the vertical movement between the plywood pieces. Lay the bed rug down on the metal floor, plywood pieces get installed/assembled on top of that. Shim however desired(or not) for flatness. Cut blocks to use as wedges, tap in under pinch seams and screw those to the plywood, this will hold the plywood floor in place. If through bolting is needed for your build, try to use the existing attach points there provided for attaching the bench seats. there are lots of those and they have solid backing.

[kbeefy]

I won't be bolting the floor down, I'm planning on keeping it more of a 'floating' installation. Whatever cabinets or Galley I have will keep it in place.I also don't plan any winter/cold weather camping, so maybe the bedrug would suffice for floor insulation. I guess I'll order one and see what I think about it.


I hadn't thought about using biscuits to hold the plywood together. I do have a biscuit joiner.

[posplayr]

This guy is an actual successful bilder and not like some of the flyby night operators. He does a detailed floor build-up (4" rigid foam with 3/4' ply glue down). for a schooie.

https://www.youtube.com/watch?v=us4WejejFWE&t=15s

[kbeefy]

Originally Posted by posplayr

This guy is an actual successful bilder and not like some of the flyby night operators. He does a detailed floor build-up (4" rigid foam with 3/4' ply glue down). for a schooie.

I've watched several of his videos, including the floor ones. Thats where I got the idea to float the floor on poly iso and use pl300 to glue everything together.