Tackling a "soft spot" in the bathroom project...I've got the bathroom floor all out. The sub floor was 1/2" plywood.Is there a better/best type of sub floor material to use, other than simply replacing with the same plywood that was there before? As in, more moisture resistant and or stronger?Figure as long as I'm doing it, and I only need one sheet of material, if there is something better to use, I may as well use it.BTW... Pretty sure I've got the source of the leaks - from above and a plumbing leak hidden under the tub - fixed already.Thank! - Coyote

Why not replace it with treated lumber plywood, then it will be resilient to any moisture, you know, the same type of treated lumber they use for making decks, only get the plywood, often used on the floor for small utility sheds.

I like that idea, and had even thought about it, but wasn't sure if there was any such thing as pressure treat plywood.Definitely sounds like an upgrade over regular plywood.Thanks!- Coyote

Advantek is very strong and what I use on any single layer repair. Its available at lowes around here. It is however 3/4" thick. Good luck, will

Don't know that I'd want any treated plywood in my rig without checking it out a bit. Perhaps marine grade might be better.

If cost is not an issue use aircraft honeycomb laminate with aluminum in both sides and you will cut the weight down by about 75%.

Anything better than plywood for floor? | Good Sam Community

DutchmenSport
Explorer
Feb 15, 2014
Why not replace it with treated lumber plywood, then it will be resilient to any moisture, you know, the same type of treated lumber they use for making decks, only get the plywood, often used on the floor for small utility sheds.
UTCoyote
Explorer
Feb 15, 2014
I like that idea, and had even thought about it, but wasn't sure if there was any such thing as pressure treat plywood.

Definitely sounds like an upgrade over regular plywood.

Thanks!

- Coyote
jayco302fk
Explorer
Feb 15, 2014
Advantek is very strong and what I use on any single layer repair. Its available at lowes around here. It is however 3/4" thick. Good luck, will
More_To_See
Explorer
Feb 15, 2014
Don't know that I'd want any treated plywood in my rig without checking it out a bit. Perhaps marine grade might be better.
QCMan
Nomad III
Feb 15, 2014
If cost is not an issue use aircraft honeycomb laminate with aluminum in both sides and you will cut the weight down by about 75%.
DutchmenSport
Explorer
Feb 15, 2014
Here ya go:

Lowe's Pressure Treated Plywood

I couldn't find anything on Advantek except a dog kennel.
Shadow_Catcher
Explorer
Feb 15, 2014
Marine grade plywood with polypropylene sheet http://www.usplastic.com/catalog/item.aspx?itemid=23329&catid=71
SprinklerMan
Explorer
Feb 16, 2014
I got some old signs from a sign shop , 5 x 8 sheets , yes 5 x 8 , this plywood is for outdoor signs . The guy sells the old signs for 5 bucks a piece . These sat out in the weather for 4 years and not a bit of rot at all . Go to your local sign shop see if you can find some
Pangaea_Ron
Explorer
Feb 16, 2014
SprinklerMan wrote:
I got some old signs from a sign shop , 5 x 8 sheets , yes 5 x 8 , this plywood is for outdoor signs . The guy sells the old signs for 5 bucks a piece . These sat out in the weather for 4 years and not a bit of rot at all . Go to your local sign shop see if you can find some

Use that, it's probably MDO (Medium Density Overlay) plywood.
westend
Explorer
Feb 16, 2014
Marine grade plywood AB, in my area the good glass filled stuff is $125/ 4'X 8', in 1/2".

An alternative is span rated OSB or exterior plywood BCX and seal it. Either one is serviceable for RV floors. I seal both sides/edges and make sure the sealant is OK with any glue application if retrofitting vinyl sheet goods as a finished floor. This means an acrylic sealer.