RV floor

Chuck Thoits

Member
Messages
4,045
Location
NH
I may have stepped in it this time. At the last show I sold my camper yup packed my stuff and walked home so to say. It went west and I went east. Well I found a new camper through a friend, 20 years newer than the old one and with a slide twice as big. Now the hitch in my giddy up the floor is junk. Not knowing anything about how they made it I figure shoot I can fix anything and home it goes. I have ripped out most of the rot and still need to rip out the section that was still good. When I got it I was thinking fine I'll rip this out put in some new floor joists and ply no big deal. I start ripping it apart and find that the floor system is a SIP panel an aluminum frame goes around the outside it has 2 frame members that go from side to side. 1/4"ply on the top of an 1 1/2" foam and 1/4" ply on the bottom.:doh: So far the only plan I have come up with is to put new ply on the top and spray foam it from the bottom. I wouldn't be able to put ply on the bottom but if I use close cell and shoot it with undercoating it would be sealed up good.So lets hear some thoughts on rebuilding this floor.
 
Chuck I replaced a floor in a camper by removing all the beds and tables and such then I put 1/2" plywood over the old floor. It has been a while ago but it was a fairly easy project. Check that rain water isn't getting in around windows and doors. Moisture is the enemy.
 
Oh boy you sure love looking for trouble. :) Chuck the issue i noticed with trailers when i helped a friend of mine redo some walls etc on his a few years back is that they done with minimalist thinking in mind due to towing weight and cost. It was a wake up call to both of us to see the materials used and how skimpy they were used. So there is no room for "if in doubt build it stout" on this kind of reno. Not the best material but what we found on his floor was OSB. Then covered with vinyl. But that was also a 20 year old trailer. I am not at all able to offer you any other ideas. I just know if i did this today the trailer would not be able to move unless i got a semi to pull it. :rofl:
 
Oh boy you sure love looking for trouble. :) Chuck the issue i noticed with trailers when i helped a friend of mine redo some walls etc on his a few years back is that they done with minimalist thinking in mind due to towing weight and cost. It was a wake up call to both of us to see the materials used and how skimpy they were used. So there is no room for "if in doubt build it stout" on this kind of reno. Not the best material but what we found on his floor was OSB. Then covered with vinyl. But that was also a 20 year old trailer. I am not at all able to offer you any other ideas. I just know if i did this today the trailer would not be able to move unless i got a semi to pull it. :rofl:
And that right there is the problem Rob. Fighting the built it right:thumb::rofl::rofl::rofl:
 
Can you lay the thin layer of plywood down & then glue in pink foam insulation & then glue on the thin layer of plywood on top? Or maybe a light duty torsion box filed with either cut pink foam board or spray in foam & slice the excess off the top & install the thin layer on top & then undercoat?
 
well my first thought was to try and raise it up and replace floor like it should be,, but maybe removing the cabinets and laying a new ply on the top side is the best fix.. how is the bottom layer of ply chuck is it history too?
 
Can you lay the thin layer of plywood down & then glue in pink foam insulation & then glue on the thin layer of plywood on top? Or maybe a light duty torsion box filed with either cut pink foam board or spray in foam & slice the excess off the top & install the thin layer on top & then undercoat?

That's along the lines I am thinking my only worry is that with out 100% bond between the ply surface and the foam you would not get the strength you need to hold up the walls.
 
I like Barts idea. The torsion box frame wouldn't add a lot of weight and should stiffen it some to help support the walls. I'm thinking maybe you can do the floor in two sections (prebuilt panels) and slide them into place left to right. Leaves a seam in the middle which isn't ideal, but you could probably offset and lap the top/bottom a smidge if you laid it out carefully.
 
How about a aluminum diamond plate floor?

That's thinking out of the box Paul.
Given that the density of Plywood is ~ 34 lb/ft[SUP]3 [/SUP]and the density of Aluminum is ~ 173 lb/ft[SUP]3:[/SUP]
The weight for a 1/2" x 4' x 4' sheet of plywood is ~23 lbs; for a 1/4" x 4' x 4' sheet of Aluminum ~58 lb, for a ratio of ~ 2 1/2 times the weight for these thicknesses.
If Chuck can handle the extra weight, that would be a nice long term fix. If he can find & use a 1/8" thick sheet of Aluminum, then the weight difference would be almost the same.

Oops! Didn't see Chuck's response above. Day late & a dollar short!
 
Last edited:
Have you checked with a local RV dealer to see if they carry sips of that thickness? I know dad has bought other materials from them for alteration and repairs, I'd think one has ran into issues like this as well and has them on hand or can special order some. Other than that. I'd probably consider making some outside of the RV using some ply, foam, and roll-able adhesive. Where you can laminate the materials, properly weight them to assure adhesion an that they are plumb.
 
Got almost all the old floor out tonight. As of tonight the new plan is to lay in a 2x6 from side to side at each point the frame bolts to the floor. That will give me something to screw new 1/2" ply looking to use Advantech. I will have to get the walls up enough to get the 1/2' ply inbetween the floor frame and the wall frame. Set the walls back down and make sure it is all flat then spray foam the whole thing from the bottom. To seal that up a layer of rubberized undercoat.
 
Top