Using foam mats under plywood flooring

[Lisa Truck Gypsy]

I have a Chevy Express Conversion van and I have taken out the carpet and there is padding underneath that is like the gym floor mats. The metal floor has the ridges and the mat is already cut so that it fills the low spot in the ridged floor and the walking surface is flat. I am planning on putting a plywood floor with linoleum glued on top. I have the plywood cut to shape but will need to nail it to something so I cut wood battens to fill the low spot in the metal floor and plan to either:

1. Glue the battens to the metal floor with Liquid Nails (?) in ALL of the low spots of the metal floor and screw the plywood over the top of the battens then glue the linoleum to it. I want the floor secured and to be able to secure a bed to it so the bed would be drilled into the plywood and the battens. I need the battens to be slightly higher that the tallest part of the metal ridge of the floor so that the plywood will not be resting on 2 tubes containing the wires that go under the floor. (when the carpet was still in the height of the mat was flush with the top of this wiring tube.)

OR
2) Glue the battens to the floor ONLY where the bed, door openings and saddlebags over the wheel wells will connect then PUT THE FLOOR MAT BACK IN and put the plywood on top and screw through the plywood/mat layer into the battens. My concern on this method is that the mat will act like a sponge and promote mold.

I plan on painting my battens and the bottom of the plywood with water based Kilz before installing on either method I choose. I will post pics so this makes more sense.

 

[Lisa Truck Gypsy]

Here are pics

 

[bullfrog]

I personally wouldn’t put anything that holds moisture under the plywood. I have used the gym mat type material and water can collect there. I would recommend a really good Rustoleum gloss paint after using rust preventive type paint. I would not glue anything to the metal floor. I would cut the plywood to where it wedges itself between the walls when laid flat. With 3/8” or thicker plywood you won’t know there are ridges there in most cases. If you want to insulate use rigid foam underneath, again I would glue nothing as there is no need if cut right as it will wedge itself into the space. I would seal the plywood completely, edges especially and would glue flooring to it but realize you may need or want to remove it someday. Wiring really should run through the ceiling or in areas where it will not be walked on or pinched as it will wear due to movement or vibration when walked on or driving rough roads. No need to fill the groves in the floor unless they are under a lot of weight or where you will need additional thickness to hold screws better. The weight on stuff tends to hold the floor in place as well and a few attachments to the walls insures nothing is going to move. These are just my opinions.

 

[Artsyguy]

No need to fasten the plywood subfloor to the metal floor. The weight of the furnishings will hold everything in place just fine. Sealing the floor is also a great idea.

 

[highdesertranger]

the battens are not needed. The plywood will lay on top of the ribs no problem. fastening depends on the set up. For example, If you attach cabinets to the wall and the floor you don't need to screw the floor down. Highdesertranger

 

[flying kurbmaster]

Personally I would drill and screw into the metal floor, or bolt it down through the floor, especially if you don’t intend having a very solid bulkhead. I would throw the mat out insulate with foam board, plywood on that no battens. I don’t have the floor bolted or screwed down, the bed cabinets etc hold it all in place but I do have a very solid dévider/bulkhead to protect the cab area in the event of a crash. Some worry about rust starting from holes in floor but if you fill the hole with silicone then put your screw in that should seal it or you can go under and spray a bit of rustproofing on the screws or both.

 

[MrNoodly]

I image any crash with enough force to send furniture flying would also have enough force to rip screws and bolts out of the thing being anchored, or even out of the steel of the van.