Preparing Floor

[KoehlerFarms]

I have seen on many of the conversions where after they pull up the wood floor and are prepping the sheet metal that they spend the time covering every single hole in the floor. What is the purpose? It seems like a lot of work to weld over close to one hundred holes. Heat efficiency? Seems like lots of work for minimal return if that is the thought. Someone please explain.....

[DeMac]

Quote:
Seems like lots of work for minimal return......

My thoughts exactly,
Google: Building Envelope

[BeNimble]

Indeed, no reason to fill every hole, in fact I believe it is counterproductive as it doesn't allow any water to escape from the floor and thus leads to rusting of the metal from standing water and molding of the wood subfloor.

I believe it has been done because the floor was solid from the factory, which was built as a school bus and not a motorhome.

[Truthseeker4449]

After dealing with one of my buses that was leaking a ton of water onto a plywood floor and observing the amount of damage and mold, I strongly encourage anyone to at least make sure they're not standing on top of soggy plywood.

However I feel trying to weld up every hole is a waste of time. I've driven my bus quite a bit in the rain with all the holes in the floor and the road spray never gets up into the bus. I opted for gorilla tape sealed over with more paint. As BeNimble mentioned drainage is something that should be considered. After my initial coating of paint, before driving the bus, I observed that water would pool in the back of the bus. I have not observed it since, presumably the paint has cracked with the flex of the body.

[musigenesis]

Drainage holes might have value, but if so you'd want them in places where water tends to pool, at the back corners and around the wheel wells. The big seat bolt holes in particular run down the center aisle and aren't going to drain much of anything.

I welded all of my bolt holes, but mainly because after rebuilding an 8'x8' section of my floor as well as the floor of my cab, it seemed silly to let a bunch of tiny holes sit there laughing at me. I don't think having little holes in the floor is really a huge problem, but I also think the work required to cover them is pretty minor in the grand skeme of things so why not do it?

[Oldyeller]

Bugs?

I have a lot of holes . . . beyond the bolt holes, so I've been thinking about holes in my bus floor.

I saw in a thread here that someone used pennies that he/she glued over the holes. I thought that was brilliant and a good use for all the pennies laying around the house. Whoever it was said they used some kind of adhesive but I can't remember which. I figured that when the time comes, if I decide to go the penny route I'll try to find the thread again and find out which adhesive.

In terms of whether it is necessary or not - I dunno but can I make the mental adjustment to accepting that I have holes? I mean, gotta watch out for the bugs.

[KoehlerFarms]

Thank you all for the replies. I have also considered the penny idea for sheer ease. Also, when placing the wooden strips down that frame my floor insulation, does everyone screw them through the sheet metal floor? I was considering liquid nails or something to stick the 1"X3" that I intend to use. Then it gives me something to screw the plywood down without putting more holes through the floor.

[GrassMonster]

I put pennies over my holes. Took 2.5 tubes of an epoxy and 45 minutes. Now I don't have to worry about water or dirt or anything else kicking up off the wheels. Considering how dirty the underside of the bus is it feels worth it to cover the holes for such little time and money.

[ewo1]

I used roofing tin caps, much wider than a penny and thinner.
A dab of construction adhesive, place it over the hole, done!

[musigenesis]

Originally Posted by KoehlerFarms

Thank you all for the replies. I have also considered the penny idea for sheer ease. Also, when placing the wooden strips down that frame my floor insulation, does everyone screw them through the sheet metal floor? I was considering liquid nails or something to stick the 1"X3" that I intend to use. Then it gives me something to screw the plywood down without putting more holes through the floor.

My experience with Liquid Nails has not been positive. I think they've skated by for decades just because of the clever name. It's especially terrible at adhering to XPS foam board, which is something you'll probably want to glue down as well unless you're using some non-rigid insulation. I've gotten much better glue results with Gorilla Glue construction adhesive.

You could also use screws, though. Screws sticking through the floor on the underside aren't going to be a huge corrosion problem and there are some benefits to having the plywood layer mechanically fastened to the sheet metal floor. In your case, though, I would screw the 1x3 strips to the sheet metal floor (using Teks wood-to-metal screws which are super easy to use) then screw the plywood to the strips.