Floor Material Questions

[SATEAR]

I am on my second classic teardrop build and am looking for input from the masters on what to use for my floor box. I have 3/4" OSB which is quite heavy and I have 1/2" Plywood. I am planning to use the 4'x8' OSB for the bottom of the box, then frame with 1 1/2" Mahogony on sides and add the 1/2" Ply to the top. This will be what I will be anchoring my 3/4" Ply walls to. Any thoughts? I have heard mention that several builders would not use OSB for flooring. Thanks for the input. SATEAR

[tony.latham]

Any water intrusion --including through screws-- will result in the OSB swelling that will not reduce. The stuff has no place in a teardrop.

Don't do it... use exterior grade plywood and seal it well.

The floor of my latest build is a framework of 3/4" pine and plywood and sheathed with 1/4" ply on both sides. Foamboard fills the voids and stiffens it up. Light and strong with plenty of meat for screws. I sealed the bottom with epoxy but three coats of the mix would be fine.





The gussets are temporary to hold it together while it gets the first layer of sheathing.

Tony

[SATEAR]

That is exactly what I was thinking. The OSB was cheap but not worth the effort. 3/4" ply on the bottom then. Should I sandwich one on bottom and one on top of the box? thoughts?

[John61CT]

The other side of the coin is adding lots of weight can be an issue.

[tony.latham]

3/4" ply on the bottom then. Should I sandwich one on bottom and one on top of the box? thoughts?

If you are suggesting two layers of 3/4", no. Gross overkill.

If you look at my framework, I have a piece of 3/4" ply inside the galley area to support vertical members, a 50-pound battery and 55-pound water jug.

Tony

[SATEAR]

Okay, so 3/4" ply for floor and then 1 1/2" rails around perimeter would be enough to anchor walls for stability?

[tony.latham]

Okay, so 3/4" ply for floor and then 1 1/2" rails around perimeter would be enough to anchor walls for stability?

Here's my floor:

1/4" plywood
3/4" internal skeleton frame with foam board
1/4" plywood

And yes, I can stand on that floor without any concern of damaging it. I would go stronger for a standy, but not a teardrop.

Yeah, for a 4 x 8" teardrop, a single sheet of 1/2" or 3/4" plywood is fine. But since my latest build is a 5' x 10' that wouldn't work.

You may be asking about meat for wall attachment??? Here's mine:



The first screws went in horizontally through the outside skin of the wall into the side of the floor (but you shouldn't do that if it's a sheet of plywood as you know).

Tony

[Squigie]

Looks like I'm late to the party, but wanted to back up the opinions provided:
You do not want OSB, particle board, 'paper board', or MDF in the structure of a trailer.

It is my personal opinion that none of the above should be used anywhere in a trailer. But I understand its use when moisture or water damage will have no impact on performance or appearance (or, that if that part does get wet, the whole trailer is underwater and a total loss, anyway).

I have not built my own trailer yet, but I've repaired more than my share of tent trailers, travel trailers, and motorhomes - and dismantled a few. Those repairs and disassembly experiences taught me a lot about what you can and can't get away with, what holds up in commercial builds, and what materials are a bad idea.

My most basic set of advice for building a trailer cabin structure:
1. Use solid wood and/or plywood. (Oak framing, specifically, has some drawbacks; but holds up longer, overall, in my experience.)
2. Seal all wood and all seams.
3. Glue and screw everywhere reasonable. (Don't nail. Don't staple. Don't use brads. Don't just glue. Don't just screw. Glue and screw.)
4. Don't forget to seal the floor. (I've seen more wall rot leading to trailer death from floors that rotted out, than from walls or roofing that failed.)

[SATEAR]

Awesome advice Squigie. I was wondering about nails versus screws. That was going to be my next question. Going to use 1/2 " Ply for the floor then to save weight and border it with 1 1/2" Mahogony framing around the ply for attaching the walls. How does that sound? Thanks!

[Squigie]

Sounds a little heavy; but if it's just perimeter framing and used sparingly, it should be good. Great rot resistance.

[swoody126]

Awesome advice Squigie. I was wondering about nails versus screws. That was going to be my next question. Going to use 1/2 " Ply for the floor then to save weight and border it with 1 1/2" Mahogony framing around the ply for attaching the walls. How does that sound? Thanks!

SATEAR, you are still over thinking this

being in San Antonio you should be able to source CYPRESS for your framing w/o too much trouble and that stuff is way high on the rot resistance list and should be substantially cheaper than mahogany

5ply(veneer ply) 1/4" plywood may be available as close as Austin butt surely in Houston (a bit more expensive butt way more strongerer !)

it would save you over 50# of sprung weight

you can get all the wood you need @

https://www.clarkshardwood.com

GREAT FOLKS TO DEAL WITH! and only 300 miles from me ;-) (it'z justa day trip)

a sandwich of 5ply 1/4" + 3/4" cypress + 1/4" 5ply filled w/ 3/4" foam would provide more strength than you can imagine and way more than you need for a TD floor

walls could be made the same way and your structure would be quite solid/sound

just this old man's 2¢ worth this morning

sw

[SATEAR]

Thanks swoody126 for the input. I do have some 1/4", 4x8 sheets of Oak Ply and the mahogony was left over from my first build. I just wasn't sure about putting 1/4" down for the floor as far as strength was concerned but I will do that now. The sheet you mentioned are at our local home depot at $11 sale right now so I will go down tonight and pick up a few. Thanks for the tips. Right now trying to get my used trailer cleaned and rust protected and ready for the build. Thanks again and I will be contacting you for more info in a few weeks.

[swoody126]

Thanks swoody126 for the input. I do have some 1/4", 4x8 sheets of Oak Ply and the mahogony was left over from my first build. I just wasn't sure about putting 1/4" down for the floor as far as strength was concerned but I will do that now. The sheet you mentioned are at our local home depot at $11 sale right now so I will go down tonight and pick up a few. Thanks for the tips. Right now trying to get my used trailer cleaned and rust protected and ready for the build. Thanks again and I will be contacting you for more info in a few weeks.

though i can't get it up here there is a very good product called OSPHO

i get it on the coast when i need it

wire brush the scale off and paint it w/ OSPHO

the stuff turns black as it cures the remaining(semi sound) rust into a protective paintable primer coating (so THEY say)

you can simply use Rustoleum primer on the remaining sound painted surfaces and paint the whole thing the colour of your choice (i like Rustoleum products and get the stuff @ either Lowe's or Tractor Supply)

sw

[SATEAR]

So....I will be completing the re-do of my trailer this week. It is a, "Work Shops Six Wheel Wonder," 4'x8'. On my first build I was able to attach the sides directly to the frame and was able to use a 4'x8' 1/4 ply for the top which fit perfectly. On this trailer it is 49' across so a 4'x8' will not be enough to cover the top and rear hatch. So I am left with attaching the sides to a frame. You guys have mentioned before the framing but I am still confused. I plan to camp here in south texas where it never gets below 30 degrees in winter so I don't need insulation. I am thinking just lay down a 1/2" ply on floor and attach 2'x2' rails on each side for mounting the sides. Will this be enough to hold them up? Can you all explain in detail with pics please how to set this up? Don't want the sides flying off on the road? Thanks and Gig'Em!