Dear Dave,
My RV has a soft spot on the floor near the kitchen and entryway. I was told by a reliable repair shop that the floor is a sandwich of thin plywood and Styrofoam and that there is no structure underneath (unlike a porch) where you can remove the top boards and replace what holds those boards up. Is that true?
I am of a mind to place 3/8″ plywood over the whole area to cover the soft spot since it seems like there is plenty of solid floor around the edges of the soft spot. I love this trailer—everything works in it and I do not want to go out and buy a new one. Any thoughts on why my RV’s flooring is soft and how I can replace it? —Richard, 2015 248RKS Bullet
Dear Richard,
Not sure who your “reliable repair shop” is, but most manufacturers do have a sandwich design for the floor. It starts with a thin lower luan sheet that is 1/8”, then block foam insulation that is either bead board or solid like a Dow Corning, and then a 3/8” or even 1/2” upper “deck” board. According to the brochure for your rig, Keystone used a product called PlyVeneer, which is made of wood veneer and a kraft board covering.
Also, looking at the expanded view, it shows double-welded aluminum floor joists, block foam insulation, and a third layer floor decking. Here is the list of what the numbers indicate:
Why your RV flooring is “soft”
Typically what happens is that moisture gets between the layers and the foam breaks down or softens. Most travel trailers have wood joists, so yours has a better structure. However, moisture is not your friend. I have not had a chance to research the PlyVeneer material, but if it’s a layered veneer with kraft paper, that just sounds like glorified paper to me even though it says “waterproof.” Kraft paper is the material that the old-time grocery bags were made of.
Identify the soft area and fix
First, you must find where your RV’s flooring is soft. What I would suggest is to identify the soft area and cut the linoleum at a fake seam, if possible. Then peel it back and see what you have underneath to work with and replace. I have replaced several soft floors that had the block foam deteriorate as well as the chipboard upper deck. We just cut out the soft material to the framework and instead of block foam, used 2x4s. This was in a heavy traffic area so the wood of the 2×4 was a superior substructure. We were not too concerned about the slight loss of insulation value of wood to block foam.
As for cutting the linoleum, even if you don’t have a fake tile-like seam, if you cut a straight line across or diagonally, when you place it back down and glue it in place, you can use a seam tape or trim tape that covers the cut.
You should be able to find something that either closely matches or looks like a decorative piece. We had one that we could not match very well, so we used one that had a woodgrain finish that matched the cabinets. We put a strip every four feet so it looked factory.
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Find the water leak while you are at it. No sense in doing it twice.
2017 Keystone Cougar used 6 months/year as a seasonal home. The high toilet began to rock. Pulling out the toilet and checking the floor structure revealed the problem was not rot but repeated compression of the thin wood over foam at the front of the toilet. Based on another DIY account, I installed a poly cutting board to the floor between the vinyl floor covering and toilet. I used a combination of stainless screws and latex (not silicon) bathroom caulk to secure the cutting board to the floor. I used the same caulk liberally around the toilet mounting ring to protect the cut wood edge. The cutting board bridges the soft spot.
We are indeed fortunate in our timing and selection of an RV. Bought before the company was consumed by a conglomerate, it’s floor has endured 2 operator induced floods and still remains solid to this day.
Thank you, Dave! 🙂 Interesting manufacturing choice. Seems pretty thin, 😯 but I guess that in order to reduce the overall weight and increase the number of vehicles that can tow it. 🤔 Thanks again for another lesson in RV manufacturing. 🙂 Have a great day, safe travels, and safe stays! 🙂
Does the soft spot happen to be over the fresh tank? I have seen a few trailers where they condensation from the fresh tank makes the floor soft in that spot.
I replaced the floor area, horizontal perimeter wall to floor joint under the fresh water tank in our lst class A motorhome. (El Dorado Encore). Condensation from filling with cold water tank rotted the entire structure. I replaced it with a sheet of 3/4″ plywood and a 2×4″ along the wall joint – both treated with Thompson’s wood preservative. I also insulated the water tank with aluminum bubble rap and also put a sheet of 8 mil plastic sheeting under the tank. (Pics available).
Winnebago has an excellent drawing on how to repair layered flooring in their older MH (1994) products. Not sure about newer units or trailers.
Recycle your pizza boxes. They need it to build your next rv floor. Kraft paper Is used to make CARDBOARD!
they have teams that meet to discuss how to make products CHEAPER, NOT BETTER