Van Floors, Why 3/4" Plywood

[VanSkulk]

The majority of the videos I have watched of van builds show people putting 3/4' plywood down on the floor.
I would like to know the reasons for this. Pros and Cons?

I'm preparing for a build and I was thinking of being more minimalistic than that (maybe thinner plywood or maybe no plywood, just some kind of water resistant padding), but I don't want to regret the first thing I do that will be very difficult to change once I've started on the rest of the build.

By the time I'm done, there is not going to be a whole lot of floor space for walking around in my van. I would like it to be fairly level and smooth, but if it's not perfect, I'm not sure I'm going to notice.

 

[Qxxx]

Hello Reg, do you have a van yet? My GMC Savana has a set of corrugated ridges and channels running down the length of the cargo area. Many people want to turn that into a nice flat floor.

 

[bullfrog]

Many here mount everything to the floor so they feel they need something substantial. I like the idea of building very light and being able to build out like a puzzle so that once installed it can’t go anywhere or mount to a side wall with a few well placed bolts. The ridges can be filled with foam mats, insulation or carpet.

 

[B and C]

3/4" plywood is a good anchor for whatever you mount (screw) to it. I won't buckle and move when you step on it either.

You need something substantial to mount too if you are ever in a wreck. Think about the missiles flying forward.

 

[Qxxx]

Floor anchor for furnishings, good point. What I did was leave many of the wooden boards for cargo lashing on the walls, and tied my couple of pieces of furniture to that. Also, the boards can be removed and cabinets screwed into the vertical metal struts too. You can see both the corrugated floor and the vertical struts in this picture.

 

[MrNoodly]

I didn't use it on my Express. I went with the jute-padded rubber floor cover that came with it. As far as mounting things goes, I drilled through the floor and bolted the stuff down.

I thin 3/4" is overkill if all you want is a flat surface. Quarter inch would work just fine, and leave you with a half inch more headroom.

 

[VanSkulk]

Yes, Qxxx, I have the van and it also has the ridges. I will definitely do something to even that out.

I'm also trying to decide if I'm going to insulate the floor.

Bob says that floor insulation doesn't help, apparently even when you are in Alaska! I see lots of people putting down inches of foam board and then covering that with 3/4" plywood. All the while Bob is laughing away. I think this is probably pretty subjective since no one really has a way to measure the impact of floor insulation.

Does anybody feel like they've noticed a difference?

I will be spending winters in Colorado. It gets cold enough here that it matters. If I were just sno-birding it. I wouldn't bother.

 

[bullfrog]

I think if you are going to be where it snows the I would do everything I could to keep it clean dry. Condensation is going to be bad enough but wet muddy shoes will be a real problem and don’t forget metal will rust eventually. I wear thick wool socks inside in winter. Having a place to sit down and take off shoes and store them outside or inside the door pockets or possibly use the driver area then have socks or house shoes with in reach and then walk through to the living area. Once I’ve got my socks on I really don’t care or feel what I’m walking on and they stay within arms reach at night as I also have sleeping socks. I just use thin carpet runners as they are cheap and easy to pull out to dry or replace. You want something that will be easy to remove and shake out that drys quickly on top. Maybe some thick coco mats or runners as the less seams the less of a trip hazard it will be. It also will make a difference depending what and how you heat.

 

[MrNoodly]

...I will definitely do something to even that out... 

You can run strips of lath in the low spots and then just a thin layer of plywood/OSB/luan/whatever on top of it.

 

[B and C]

I use these: https://www.amazon.com/gp/product/B001E5CRFQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Great for keeping feet warm inside.

 

[Qxxx]

Yes, Qxxx, I have the van and it also has the ridges. I will definitely do something to even that out.

I'm also trying to decide if I'm going to insulate the floor.

My Savana build is very minimalist, and I didn't insulate anything, although I have been in 24F temperatures in the winter (in southern AZ no less).

As others have mentioned, the more you put on the floor, the less headroom you have. As it's only 57" of so in the Savana to start with, 2" of stuff on the floor means having to bend over that much more. I think the roof and sidewalls should definitely be insulated if you're wintering in CO. You can see how Shirley Sofi added polyiso (???), I believe it is.

https://vanlivingforum.com/showthread.php?tid=40966&pid=504385#pid504385

In regards smoothing out the corrugations, I didn't bother either although I think adding slats in the grooves is a good idea. All I did was add a heavy 3'x5' polypropylene doormat over the heavy vinyl pad on the floor. The doormat can be removed and the dust washed off in a car wash.

https://www.lowes.com/pd/Mohawk-Hom...n-3-ft-x-5-ft-Actual-60-in-x-36-in/1000427755

 

[Sofisintown]

Mine is Chevy Express and no insulation on the floor. There is 3/4 inch plywood on the floor, covered with vinyl flooring. Furniture is affixed on it, as well as on wood planks (1"x4") added on the sides. On the roof, 1 inch polyiso (two 1/2 inch sheets) held in place with glue and 2 metal strips. I covered the walls with carpet and the roof with headliner.

It is not worth losing an extra inch in height to insulate the floor, like Q said.
Your back will thank you.
The carpet hides a lot of uneven-ness. The headliner has a thin foam backing that evens out the appearance a bit, and also saves your head from bumping on the ribs all the time.
Cheers!

 

[MrNoodly]

The reason I say 3/4" plywood is overkill is that it's what's used to span the 16" spacing on floor joists without flexing. In a van you're spanning two, three inches. You can use much thinner plywood and still get no flexing between "joists." As far as anchoring things to the floor goes, manufactured sheet woods (plywood, OSB, MDF, etc) aren't very good at holding screws, especially with the vibrations of driving.

 

[B and C]

I respectfully disagree. Plywood is good at holding screws. My roadtrek interior is built with plywood and screws and no problems with them coming loose in the 20 years it has been around. OSB less so and MDF not good at all for holding screws. 3/4" plywood will give a good amount of bite for the screws to anchor stuff.

Poking holes in the metal floor is asking for rust and then letting the screws go where the rust has weakened the metal.

 

[highdesertranger]

I agree with Brian, 3/4 plywood holds screws well. I wouldn't use OSB or MFD for anything.

also in my cargo trailer the floor is 3/4 plywood and it gets cold as hell. it will get insulated.

highdesertranger

 

[flying kurbmaster]

I would insulate your floor if you intend to be anywhere where it gets colder then 45 f. Or warmer then 75 f . 3/4 inch ply is a good insulator a little less then R1 I think. 1 inch of timber is R1.41 if you could do better by laying a frame work of 3/4 x 1 wood strips with condensed foam insulation in between then a sheet of 1/2 inch or 3/8 inch ply that may have a better R value. The more insulation you can get under your floor the better, it makes a big difference, no matter what Bob says. You can find engineered science to prove this. Of course loosing height in a van is a consideration. You can anchor furniture through the Métal floor or to the walls that is not an issue. I think if you had a wreck the 3/4 inch screws into the plywood would let go if that was all you were counting on as an anchor. You can test this if you like. Take a desk or a set of drawers screw it into a sheet of 3/4 ply and push on it you will see it won’t be very hard to knock it off. A wreck is very violent not much will be in place in the back of your van. A strong bulkhead may be a better idea for protection.

 

[MrNoodly]

My roadtrek interior is built with plywood and screws...

I suspect the screws go THROUGH the plywood into something more substantial.

 

[B and C]

All the cabinets are built with plywood. I removed the cabinet over the old microwave to make room for the new convection oven and it was just screwed to the other cabinets, not to the wall or ceiling.

Numerous screws will be required to hold anything in place, just one here and one there won't cut it.