Floor plywood question?

[ol trunt]

At this point I think I would leave a wood over metal floor alone unless I found an obvious bad spot. Even then I'd just cut out the bad section and replace metal and/or wood and move on. Both Tango and I fought our way through lino over steel floors the lino being secured in hot tar in our ancient buses. The adhesion and seal was about as good as could be accomplished--and a royal PITA to work with. As I remember, Tango said his floor was in great shape under all the tar. Mine was too except for about one square foot at the back of the bus where the rear door had leaked. I had to cut that section out anyway to allow my shower stall to drop below the floor so no big deal. Since I wanted to build all my interior of welded steel, I really did need to strip the floor anyway.
When I did my second conversion (40' MCI) I left the 1" thick plywood and framed out the interior with wood. Lots of ways to skin a cat.
It probably isn't really worth the effort necessary to tear up and replace entire floors. If in a particular case it is---then I'd be looking for another bus. None of us is going to own our bus long enough for our floors to become dangerously weakened. We will either have died of old age, lived up the bus dream or upgraded to a "real" house long before that happens so just build it safe and sensible and "Geterdone".
Jack

[rdeannag]

So, why is it important to pull up the floors? For example, if I get a late model bus with low mileage, etc., why would I want/need to remove the floor? Does removing the floor gain you inches in height? Unless I get a bus 10 or more years old, i’m not pulling the floor if there is no sign of deterioration. Comments, please! I need to understand this

[bus-bro]

If you pull up the floor, you could rust coat the steel, add some insulation, and install a solid floor.

I used one inch pink styrofoam topped by three quarter inch tongue and groove subfloor plywood, screwed to the steel. I tired to use as few screws as possible, all things being considered.

[Tango]

I'll say it again...building anything on top of an unknown foundation is unwise. I have seen perfectly clean looking plywood removed to reveal serious rust through that was not really visible from below.

My dos centavos.

[Megabea]

my bus looked great from the outside , but under the plywood was a different story , The thing that you need to remember is that the school bus drivers use a garden hose to clean them out.
after washing the puke out the back door there is a good chance the water leaked around the edges somewhere , never is a floor 100% waterproof

[PNW_Steve]

Ok. Now I am leaning back in the "pull it regardless" direction.

Thank you Everyone for the input.

[Twigg]

Originally Posted by PNW_Steve

Ok. Now I am leaning back in the "pull it regardless" direction.

Thank you Everyone for the input.

I'm still leaving mine in

I am careful and meticulous (anal) about a lot of things, but mine has no rust, the plywood is dry with no signs of ever being wet, and it is sealed all around the edges. It's stayin' put!

[Robin97396]

That's what I was saying about my floor two years ago. I've mentioned several times that my floor shows condensation during the winter much like a glass window. Yesterday I was mopping and could see swell where the plywood joints are. I guess mine will be coming out after all. I needed insulation in the floor anyway. I regret loosing all the L-track, but it's aluminum in direct contact with the steel subfloor. Not good for bare feet.

[Twigg]

Originally Posted by Robin97396

That's what I was saying about my floor two years ago. I've mentioned several times that my floor shows condensation during the winter much like a glass window. Yesterday I was mopping and could see swell where the plywood joints are. I guess mine will be coming out after all. I needed insulation in the floor anyway. I regret loosing all the L-track, but it's aluminum in direct contact with the steel subfloor. Not good for bare feet.

So I am planning 1 1/2" of R-Max and new plywood on top. It will be well insulated.

[Robin97396]

That sounds about right with 3/4 ply.

This was a dry floor, still doesn't have any leaks. What makes me think that it's condensation causing the problem is that it's all over instead of being a problem in one spot. That and visible condensation on the floor. Carpet seems to help, or it just acts like a sponge. Not sure.

I might have bought a taller bus if I had thought it would be necessary to insulate the floor like this.

[PNW_Steve]

I took a hole saw and took "samples" from the plywood every 3-4' going down the length of the bus. All were dry and clean until I got to the back 3' of the bus.

There I found moist plywood......

I decided to pull it all up.

What I found was mostly good plywood and some wet. Most of the steel floor was perfect. The back 5' or so showed very mild surface rust.

The area that did show rust was very mild surface rust.

I will Ospho the affected areas and paint!

Progress!!!!!!!!

[PNW_Steve]

Plywood is pulled up and I found some areas of very light surface rust: