weak flooring

[[email protected]]

What is under the floor in the bathroom of a 2004 Gulfstream
Crescendo 8386? Water has made the floor weak. Newly purchased
and I'm replacing it.

[Bill W]

I had the same problem on my 2007 Conquest. There was OSB. Good luck.

[bmojmhs]

The floor is made of 3/4" OSB or strand board. Once wet it turns to mush and needs to be replaced.

You don't say if you are doing the replacement or having someone do it for you.

If you are doing it, use 5 or 7 layer plywood (available @ Homedepot, etc.) Treat it with water seal then put it down. Make sure you seal the cut e dges of the OSB as once the seal is broken it will get wet again.

When you take out the old OSB you will notice a steel or aluminum framework supporting the floor. You will need to attach (screw) the plywood to the framework for support.

So plan to take out the OSB back to a supporting frame. If not possible the plywood will cantilever short distances and still stay rigid.

Once attached, get floor levelling material (Home Depot, etc) and apply. Some one makes a paste floor levelling material. Everyone else makes the material using water, which I did not want to do.

Good luck.

[gwirth]

Water proofing the floor starts at the top. My 2004 Attrium had a tile floor sealed at the edges and I have never had a problem. When at replaced the flooring throughout my coach, I used luxury vinyl planks glued down. Not the snap together stuff. This was also sealed at the edges with silicon caulk. Doing all the waterproofing to the plywood is not a bad idea, just remember to seal whatever flooring you used or the plywood will still rot with water damage.

[[email protected]]

Thank you guys. I was worried what I'd find under the floor. You
can never give me too much info.

[trotline]

Marine plywood is maximum resistance to water rot. AKA treated plywood

[trotline]

Floor rot is not a problem if your RV is dry. Not leaking. I used regular plywood, sub floor level, structural. Second layer 1/4 inch smooth for vinyl flooring.

[Bamawinger]

We had same issue on our 03 8368 Sun Voyager
Shower was leaking behind faucets.
Had to remove walls and shower.
Glad to see steel stringers under the floor!
Had to replace floor under washer/dryer and in kitchen area where previous repair(when?) was done.

[Frnzkchar]

I had the same issue original owner put in storage with bathroom vent wide open....
Rebuilt and beefed up floor joists with bed frame steel....