Subfloor question: corrugated and welded floor plates

[skuld]

After getting the floor off my 1992 Wayne G30, I was a bit surprised by the floor. I was expecting flat sheet metal across the bottom shell of the bus, but it is actually corrugated metal with flat mounts for the seats welded on top, and flat pieces welded along the front sides for whatever reason.



I am deciding how I should proceed. Originally, I planned on cleaning and painting the metal, 1/2" rigid foam board with occasional square wood supports, 1/2" plywood, finished flooring. With this new base layer, I am not sure what needs to go directly on the metal do avoid damaging the insulation.

I am figuring my two options are: removed the metal plates and put more support for the plywood to not crush the foam board; or add wood around the plates to create a mostly flat surface for the foam and continue as planned.

Either way, I will take a wire wheel to surface rust and put rustoleum over it. One of my biggest concerns (and I should probably just get over it) is height. I am 6'0 and so is my bus. With the original floor I can stand up straight with shoes on. I would love to still have this ability.

I should add that this is not going to be a full time living bus, and will be used much more in extreme heat than extreme cold. I still want to get good insulation on the walls and floor, but I am starting to wonder if I should just cut some rubber and add a 1/2" sheet of plywood and keep it super simple.

Build Thread: http://www.skoolie.net/forums/f27/na...e-19067-2.html

[Rusty]

Wow, that is weird. Looks like a pickup truck bed.I bet it is harder to get those plates off than it looks.

Raise the roof, stoop, or don't insulate--all lousy options.

Get 'er done.

[Robin97396]

Most people use sheet metal to patch the larger holes. Other than that, about one old truckbed should make patches for those holes.

For what it's worth, patch the floor the least expensive way that also closes the floor as a vapor barior. You're not going to see the floor again hopefully, so patch it well and inexpensively at the same time. The insulation panels will conform to the floor.

I've never seen that flooring before either except in truck beds.

[skuld]

Originally Posted by Robin97396

The insulation panels will conform to the floor.

I was under the impression that I should avoid crushing parts of the insulation, that it lost a lot of value when deformed or pierced. If that's not true I really only need to worry about keeping the floor a level surface. I could frame the entire floor, but I just hate the idea of losing more than an inch.

I think I'm going to try to remove one of the plates to have an eventual flat corrugated surface. I could honestly frame it and use spray foam for the weird surfaces, but I don't love that idea.

[Robin97396]

I have to assume you're going to use at least 1/2" thick insulation panels on the floor, and insulation certainly is reduced in value when it's compressed. Either way you have to get that steel floor sealed up first.
The floating floor avoids metal contact to exterior surfaces, which makes a difference when temperatures are at extremes.

Each winter I wish I had insulated my floor. Cold feet again.

[JesuitJohn]

Originally Posted by skuld

I could frame the entire floor, but I just hate the idea of losing more than an inch.

I am just starting with my bus and have the same height concern. I'm thinking of spray foaming the floor from underneath the sheet metal. Then I only lose the thickness of the flooring in height. I'm hoping the foam can be prayed easily down below under the bus, expanding into all the odd shapes.

Of course, I'm not sure what spray foam does when attached to sheet metal on a moving bus or how clean you'd have to get the metal for the foam to bond to it. The man I know who has a spray foam business says he has foamed the underside of metal horse trailers and toy haulers and it worked fine.

Good luck! I'm interested to find out your solution.

[skuld]

Spraying underneath is an interesting thought. In my case it would be almost worthless, though. My metal floor is welded to the metal frame along the walls, so that would be a lot of conduction through that contact. The area right beneath the metal floor would be fine in some places, but most places are right over electrical or drivetrain components which I would be wary to spray toward.

My idea with spray foam would be a way to make the corrugated floor level, filling in all the valleys. I think this is ambitious to think I could get spray foam flat enough for a floor by laying it this way. And with the next layer so close to the peaks in the corrugated floor, I think that this will be ultimately worthless.

I still have not decided the best way to attack this floor. I think it'll just be a matter of experimenting until I give up and just slap plywood over it without insulation

[EastCoastCB]

Just slap some foam board down with some plywood.

[skuld]

So I posted a bit more in depth in my build thread but I wanted to post here as well. Huge pet peeve when you find someone who asked a question, but never posted their results.

Basically, cleaned the rust like crazy, painted with Rustoleum rust converter, put down hard foam insulation, and put down tongue-in-groove OSB. It will be about 1.5" from the metal in the end, but I've come to terms with that.




I need to go back and add some scrap insulation to make the floor a bit more level so it doesn't bend as much when walking. The middle aisle is well supported, which will be the highest traffic area, so I'm not that concerned. I plan on gluing the insulation down, and haven't decided if I will glue wood to insulation or let it float. After that, frame/insulate the walls then put down vinyl flooring and I'm good to go.