New Flooring Over Plywood

[Rail73]

Looking to lay new flooring over the existing 5/8' plywood in my 6x10. The current floor is a bit weak, and I would like to have something that is:

a. Stronger
b. Looks better
c. Easy to clean

Any suggestions?

[Tigris99]

if 5/8 ply is "weak" there is something wrong you need to look into. There is nothing your going to be able to simply put over it that wont have issues later, especially any type of "flooring". Best you can do is put new plywood over it for now but if the 5/8 is weak then there is a moisture problem and the new ply you put in will end up with the same issues.

Now for something to cover, something that goes on as a roll in one piece would be best. plywood by itself isnt designed for constant wear of walking around and such, so anything from sealing and urethane to a good rolled type floor covering used in places like bathrooms and such is a must.

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[aggie79]

I would guess that the reason floor feels "weak" is because of the span distance between steel cross-members. I would add 1x2 poplar stiffeners perpindicular to the cross members 16" on center or thereabouts.

[John61CT]

Do not just add that much weight without careful thought.

Fix / replace rather than just adding on top.

[McDave]

It may be better to just replace the 5/8" with new 3/4". Then finish with flooring of your liking. Is the trailer new or used? The reason I ask is that cargo trailers tend to get used hard, often more than designed for. You might want to get under there and inspect the crossmembers and also be sure the screws that secure the floor to the members are there still. I have seen crossmembers that were bowed more than an inch and had pulled the screws from having a heavy load that was concentrated in the center.

McDave

[hankaye]

Rail73, Howdy;

It may be better to just replace the 5/8" with new 3/4". Then finish with flooring of your liking. Is the trailer new or used? The reason I ask is that cargo trailers tend to get used hard, often more than designed for. You might want to get under there and inspect the crossmembers and also be sure the screws that secure the floor to the members are there still. I have seen crossmembers that were bowed more than an inch and had pulled the screws from having a heavy load that was concentrated in the center.

McDave

What him (/\ /\ /\), said.

hank

[MtnDon]

(I see others have added some of my thoughts, since I started writing a reply, then took a break for dinner....)

Cargo trailers often have the frame cross members spaced at 24".

Plywood that is designated for use in residential and commercial building construction has a span rating stamped on one side. It is a number such as 40/20, 32/16, etc. The right-hand number is the maximum spacing of the support joists. %/8" often is rated 40/20. 3/4" plywood is often rated 48/24. If we apply similar floor load to homes and trailers, then the 5/8" is overspanned if the cross members are at 24". My CT came with a 3/4" plywood floor. There is no discernable springiness.

Adding a second layer of even 5/8" plywood will not increase the stiffness as much as you might think. When loaded, each layer will sag and slide over one another. The best solution if the present floor does not provide the stiffness you desire, would be to remove the 5/8" and replace it with a thicker plywood rated for the span. Remember the panel span rating is a maximum and when it comes to a home, a good builder goes better by maybe limiting the span to 16 or 19.2" when using a panel with a floor rating of 24.

As for what to use as a floor finish, depends on intended use. I like those interlocking rubber matt squares unless vehicles will be rolled in and out.

[Rail73]

Thanks, Everyone!

You folks nailed it - the frame cross members are spaced at 24". I've had the trailer since new (10 years ago) but it has only seen very limited use (no heavy loads) and there is no structural or water damage. I already insulated the sidewalls and put in 1/2" birch ply there, so pulling out the existing floor would be a PITA so I think I will leave it as is, but add another layer that is screwed and glued to the existing plywood, then lay some sheet flooring over the top. Many thanks for the suggestions!

[Rail73]

OBTW - weight isn't an issue here as I'm pulling this little trailer with a 2500HD Duramax.