Rotten Bathroom Floor-- How To Fix It?

[OldAsDirt]

Rotten bathroom floor 1999 Monaco Diplomat.

Can any one tell me how the MH subfloor is made. How about layers or thickness of subfloor. What about structure/frame under subfloor to support the new floor after old floor is cut out?

Can a 3/4" piece of plywood be put over the old floor, and the toilet attached this way? What about the toilet flang, it would need an extender of some sort?

Thanks,

OldAsDirt

[desertdeals69]

I would cut out as much of the rotten wood as possible and then replace it with exterior plywood.

[Larry196]

Don't use a saw to remove the floor!! Not knowing what is down there!!

Use whatever you have in your tool chest and take your time-One layer at a time until you can see what's under there.

Have you tried to crawl under and look up at what your trying to remove?

The floor underlayment generaly is 3/4 inch plywood, put down and then the walls are put on top, so it may require some sawing, but not until you know what is under the floor.

Take some pic's as you go along and post them on the forum, might be someone that has the same problem.

Good Luck

Larry

[wolfe10]

To expand/modify a little on Larry's suggestion.

You DO need to be careful to not cut into any below-floor beams, wires or plumbing. But once you have "cored" the floor to determine it's thickness, and have checked in the basement that nothing is "notched into" the flooring (very unlikely), you can set a saw to cut through all but the last 1/32" of the floor thickness to give a clean, quick cut.

You will need to determine where the support "joists" are in splicing in a new piece of floor, just as if this were a stick built house (or do some "re-engineering" to support it).

Brett

[desertdeals69]

I have done this type of repair. Don't use a circular saw, use a multifunction tool with a straight blade and you can plunge cut and make square corner cuts. Draw a line outside of the rotten part and it is easiest to make it square or rectangle so fitting a new piece is easier. Cut down about a quarter of an inch and peal out that layer of wood. If you are lucky the rot will have not gone all the way through. There may be foam insulation sandwiched between two layers of wood. Just rebuild the thickness to a flush floor.

[hermanmullins]

oldasdirt with a rotton floor, Wow.

Having replaced rotten flooring before in a home and in a M/H are completely different. There are so many thing under the M/H floor. I would make a frame out of 1 X 2 or 1 X 4 s large enough to allow your router cutter to just clear to rotten area. Then make several cuts around the inside of the frame cutting a little deeper each time until you just barely brake through the floor. At this point you can see what is close by and if you have space to put bracing around the opening to give you something to secure the repair to. I would use pressure treated wood and exterior or Marine Plywood. I would coat every thing with primer. I would also glue and caulk everything. As you make the repair you might look to see what may have caused the rot in the first place and correct it if possible.

[desertdeals69]

I wouldn't use a router, I use an oscillating multifunction tool which is not so messy and more precise. By cutting down about a quarter of an inch at a time and peeling out the wood you can see what if anything is hidden. I have done this type of repair in RV's many times.

[OldAsDirt]

Thanks fellows,

I have talked to Monaco and they say there are two layers of 5/8th OSB wood in subfloor, but what I've seen on the web it appears there is only one layer. I would like to run across someone that can tell me how the framework is laid out under the toilet. Why not weld in some supports for the floor to lay on?

Thanks Again,

OldAsDirt

[desertdeals69]

I don't think that there is any frame work. They usually cut the 4" hole and screw the toilet flange in place and mount the toilet. If you have to go all the way through the total floor just block the opening all the way around by about 1" and then set the new floor piece in place and screw it together. Use glue to secure it.

[hermanmullins]

I just reread the question. It asked if the toilet could be screwed to 3/4" plywwod. To that question, Yes. But there is no way I would put a saw to the floor right over the Holding tank that would be right under the toilet.

[Guest BillAdams]

Anyone who knows how to properly work wood would not be concerned about cutting into plywood where ever it's located. If you have a 3/4" thick piece of plywood and you set a circular saw to the appropriate depth, you can't cut anything below. This is where "measure twice, cut once" becomes critical but getting the necessary cuts accomplished should not be an issue.

[hermanmullins]

Bill,

Yes most people that work with wood knows how to set the depth of a skil saw, and it works fine in the middle of a room. However if you are in a M/H bathroom you would have limited space. A skil saw blade set to make a 3/4" deep cut has a very limited run before it hit objects like walls.

Now to the problem at hand. If OldasDirt's toilet is on a raised up platform he might be able to remove the toilet and remove the entire platform top the toilet rest on. Problem solved and no sawing.

[ftartagl]

First of all you must fix the problem that created the rotten wood to start with. My toilet is in my slideout which rotted the entire floor under the toilet.On the slideout the floor is 1 layer of 7/16 OSB over a layer of 1/8 luan glued and screwed to and aluminum subframe. Not to leave out the tile floor above all. I used a multi tool to cut and a scraper and wood chisel to get down to the frame. Then I let it dry out for a while screwed down the OSB first then the luan. Then I applied a sealent to the wood and a commercial grade peel and stick tile. then reinstalled the cabnetry and tiolet. If your toilet is not in a slide. and has a tile floor, there will be 2 layers of OSB plywood. the main floor then a floating floor which the tile is set on. this prevents the tile from lifting and crackink with the flexing of the coach. I have an 04 Monaco Diplomat. i have taken all the tile out of my coach and replaced all the rot then installed engineered wood thru out. and peel and stick in the bath. good luck.

[Guest BillAdams]

Why in the World would anyone consider my post as being defensive? Defensive of what? Measure twice, cut once? Know what you are doing before you start? Yep, that's a tough stand to defend!

[Sundancer268]

I just rebuilt the riser in my Gulf Stream, the original was rotted out and only made of 1/2" plywood. I made the new one out of 3/4" and installed a sub-frame to mount it to. The old unit was attached to the 1/8" wall paneling only with screws and the wall board was ripped and not holding anything. The toilet was only supported by the flange and the angled piping to the holding tank. The repair was covered with a single sheet of vinyl flooring from the tub up the face and over the top of the platform. All edges were sealed with RTV tub and tile caulk and when dry the toilet flange and piping reinserted into the tank and the toilet reinstalled.

It is now as solid as a cement floor. Nothing moves or wiggles.