Floor damage beneath toilet

[jbt816]

We just returned from a week long trip and I noticed that the toilet would rock back and forth a little. So that got my curiosity. While on the trip, I probed the flooring around the toilet and it seemed solid.

I removed the toilet today and the flange was cracked but the flooring was soft directly beneath the toilet from water damage. The floor is 1/4 wood sandwiching about 2 inches of styrofoam.

My best guess is the toilet flange seal wasn't doing its job because I don't think I had an actual leak at the toilet fill valve.

These are my thoughts for repair. I'm asking if the general consensus agrees or has a better idea.

1. dry out the floor
2. cut out a piece of plywood 1/4" or 1/2" thick and slightly larger than the toilet base; paint it.
3. mount the new piece of plywood to the floor
4. attach the toilet flange to the new plywood and reattach toilet

The flange has a threaded barrel that slips into a rubber grommet/collar of the black tank. I think I should have enough play in barrel/collar seal to raise the flange by the thickness of the plywood.

This is all I got for now. I could try to cut out the damaged flooring but I don't know where the metal floor framing is located to rest the new piece on.

Thanks in advance.

[bsmith0404]

That’ll work if you don’t mind the plywood being there. Personally I wouldn’t like it. Laminated floors can be tough to repair. Another option would be to remove the vinyl and put plywood on the entire floor and put new vinyl over it. I’m sure others will have some different recommendations.

[NH_Bulldog]

He is my bathroom floor rebuild from a similar issue:

I started out thinking of a spot repair and ended up with a new floor. I cut and salvaged the vinyl for reuse and laid 3/4” quarter round after reinstalling to cover the edges.

[jbt816]

Originally Posted by bsmith0404

That’ll work if you don’t mind the plywood being there. Personally I wouldn’t like it. Laminated floors can be tough to repair. Another option would be to remove the vinyl and put plywood on the entire floor and put new vinyl over it. I’m sure others will have some different recommendations.

Oh, I didn't say I'd like it. I thought about removing the vinyl and overlaying the entire floor with plywood..... I still may.

[jbt816]

Originally Posted by NH_Bulldog

He is my bathroom floor rebuild from a similar issue:

I started out thinking of a spot repair and ended up with a new floor. I cut and salvaged the vinyl for reuse and laid 3/4” quarter round after reinstalling to cover the edges.

You completely removed all of the flooring in the bathroom and then built it back up again with 2x material and plywood?

1. Did you decide to do this because there was no good way to do a spot repair?

2. In the photo just previous to the plywood (pic #3), are those two metal struts on either side of the toilet? Can a lip (piece of angle) be attached to support a piece of flooring on 4 sides so that a spot repair be made?

[NH_Bulldog]

So my floor damage was pretty advanced, and the top luan layer basically disintegrated so I pulled it and used an oscillating tool to get tight clean edges. I pulled all the foam out and found the bottom layer of luan was rotten too. I went underneath, opened up the coroplast and cut the Darco fabric back to clean everything up.

I went to Home Depot and picked up a 4x4 sheet of 5-ply 1/4” plywood , a 4x4 sheet of luan, a 4x4 sheet of 2” foam, a 2x4, two tubes of high tech construction adhesive, some 1 1/2” all weather deck screws, some 2” self-tapping wide head screws, one can of spray adhesive, and two lengths of 1/8” thick by 2” wide by 3 ft long steel bars.

The two aluminum bars you see are part of the factory floor framing and I didn’t touch those. But you could use angle to make a lip. My concern with that is the electrolytic reaction between dissimilar metals, so you would need aluminum angle material.

From underneath, I ran the two steel bars lengthwise between two frame cross members, one between the toilet fitting and the wall, and the other halfway between the toilet fitting and the exterior wall. From above I laid in new luan and then added wood framing to support the floor as seen, then I glued in the foam, then glued down the plywood floor (I used cardboard to template the floor and traced onto the plywood and then cut to size. I then screwed the floor down, used floor leveler to fill screw heads, and then sanded and vacuumed clean. Applied spray adhesive, relaid the vinyl, added stained trim around the perimeter and a metal threshold. The floor is more solid than it ever was.

Underneath, I spray-glued the Darco back into place, sealed the seams with FlexMend and then “stitched” the coroplast closed with zip ties.

[skids]

Looks real nice.

[atkinsb3]

The floor around the toilet in my passport started getting spongy. Noticed a drip from underneath near the black water valve. Took off the chloroplast and the water has been dripping off the top of the black water tank due to a leak in the toilet flange... lovely. So I get to go through the same thing you did.

I filed a claim with my insurance to see what they would do, but regardless, I'll do the work myself.

Thanks for pictures and info.

[atkinsb3]

Originally Posted by jbt816

We just returned from a week long trip and I noticed that the toilet would rock back and forth a little. So that got my curiosity. While on the trip, I probed the flooring around the toilet and it seemed solid.

I removed the toilet today and the flange was cracked but the flooring was soft directly beneath the toilet from water damage. The floor is 1/4 wood sandwiching about 2 inches of styrofoam.

My best guess is the toilet flange seal wasn't doing its job because I don't think I had an actual leak at the toilet fill valve.

These are my thoughts for repair. I'm asking if the general consensus agrees or has a better idea.

1. dry out the floor
2. cut out a piece of plywood 1/4" or 1/2" thick and slightly larger than the toilet base; paint it.
3. mount the new piece of plywood to the floor
4. attach the toilet flange to the new plywood and reattach toilet

The flange has a threaded barrel that slips into a rubber grommet/collar of the black tank. I think I should have enough play in barrel/collar seal to raise the flange by the thickness of the plywood.

This is all I got for now. I could try to cut out the damaged flooring but I don't know where the metal floor framing is located to rest the new piece on.

Thanks in advance.

Have you attempted any repairs yet? I think if you look at the underbelly of the trailer you can see where the coroplast is screwed to the metal floor joists. That will give you an idea of where they are. It also appears to me that in my case the bathroom floor and immediately outside of the bathroom door uses the black and grey tanks as support. I talked to the RV shop and was told it would be $4 - 5K for them to fix it (haven't got an official estimate yet). They also said sometimes it's better just to overlay the floor with plywood because in some cases it could weaken the floor around where it's cut it out. Don't really know, but it bears some thinking and investigating before cutting into it.

[wiredgeorge]

Originally Posted by atkinsb3

Have you attempted any repairs yet? I think if you look at the underbelly of the trailer you can see where the coroplast is screwed to the metal floor joists. That will give you an idea of where they are. It also appears to me that in my case the bathroom floor and immediately outside of the bathroom door uses the black and grey tanks as support. I talked to the RV shop and was told it would be $4 - 5K for them to fix it (haven't got an official estimate yet). They also said sometimes it's better just to overlay the floor with plywood because in some cases it could weaken the floor around where it's cut it out. Don't really know, but it bears some thinking and investigating before cutting into it.

Perhaps start a new thread and ask for suggestions. The person you asked about how they went about a fix hasn't been on the forum since March. The fix you are asking about has been done by several other members (can't recall whom exactly) and I think if you start a new thread you will get the advice you need. I can give you one bit of advice; the $4-5K guesstimate you received means someone wants a vacation in the tropics or is sending a kid to school.

[NH_Bulldog]

Scroll up and read/see what I did. I seriously do not recommend slapping a new piece of plywood down over the rotted stuff and calling it good. It should be removed, cleaned, sanitized and rebuilt with new materials. Also, the tanks provide no structural support whatsoever, they rest on angle steel and there is a clear space between the top of the tank and the bottom of the floor system