Best flooring for a utility trailer?

I have an old utility trailer. The original floor was a 4x8 sheet of painted OSB. 15 years later, it has rotted through, and needs to be replaced. What should I replace it with?

Another sheet of ~3/4in OSB is cheap, and a gallon of whatever outdoor paint is on the oops shelf will probably get me another 10-15 years of service. Maybe more if I bother to cover the trailer with a tarp.

Plywood is not much more expensive, will it weather better?

What about an expanded steel grate? They are considerable more expensive, but possibly somewhat lighter than wood. I don’t weld, so it would be held on with the same bolts used for the wood.

It is a small trailer (the bed is 4x8), and it doesn’t have the appropriate mounting points to install 2x4s, 2x6s, or other hardwood planks. If this is far and away the best answer, then I can always put some holes in the frame, or attach boards to their neighbors. My thought is all wood rots, so unless hard wood will get me another 20 years even when I neglect it completely, I’d rather stick to a simpler solution.

Thanks for any advice.

Why hardwood and not pressure treated, followed by treating it like a deck and ‘waterproofing’ it as needed?

CMC fnord!

My former neighbour just used a thick [?1cm] sheet of fabric-backed rubber sheet, which I think he got as scavenge. It was light enough to remove and fold up when necessary, stopped everything he carried clanging as he drove, and lasted all the time I knew him.

Wood rots, steel rusts, any material deteriorates.
Simplest, cheapest is best unless you use it heavily enough that it’s worth the investment to do more.

Just based on conventional wisdom (what most people do), most such trailers I see in back yards have wood floors. But those I see constantly on the road, like lawn care or construction companies, have metal grate floors.

Just done the same job (floor and sides). Used a recycled MDPE sheet (8×4) material we have here in the UK: the trade name is ‘Stokbord’. At 6mm thick (1/4 inch) it’s cheaper than marine grade ply, and should last forever. Farmers here use it for small-scale pig housing and similar. It’s more prone to sag at high temperatures than ply, so maybe a bit more support needed. Good luck!

I’ve a large double axle utility trailer. It came with pressure treated 2x8’s. Water drains through since there is a bit of space.

When I redid the floor of my 4X8 utility trailer I used 5/4"x6" PT decking. Rather than drilling holes around the metal side flanges I put some 2x4 cross pieces that extended under the flanges then screwed the deck boards to the 2x4s. Since all wood was pressure treated it made for a very sturdy and long lasting deck.

Googling, a 4x8 sheet of pressure-treated plywood is fifty bucks at Home Depot.

I’d use pressure treated wood decking. Expanded steel would be best, and I do weld, but it would be expensive, just one 4’ X 3’ foot piece will cost more than $50.

You might look at Trex or some similar composite decking material. My outside deck is ten years old and seems impervious to weather.

My utility trailer has a sheet of 3/4 inch exterior plywood for a deck. It’s been there for about 15 years. When it finally gives up the ghost, I plan on replacing it with the same thing. I figure 15 years is a good deal.

Thanks for the suggestions everybody, particularly the idea of using plastic. I think a 4x8 sheet of plastic would probably be the best option, but I don’t think I’ve ever seen something like that in a hardware store. Searching online (the most I can do these days) it does look like a specialty item, and maybe about $100+ for a 4x8 sheet. Please let me know if I’m wrong, and I just need to look under a particular trade name or something.

Maybe this summer I’ll be able hunt around the city, as I’m sure some lumberyard someplace carries plastic. The closest material that is stocked locally is just plastic deck wood, which is expensive, and has the disadvantage of being in planks not sheets.

I think the only repair option while we’re all grounded is OSB or plywood and some waterproof sealer, so what solution I pick will probably depend on when I need it.

I think you’ll be well over a $100 for a 4X8 sheet of plastic strong enough for you. If you do use a sheet of OSB or plywood you might want to coat it with the spray on bed liner stuff.

Really, if a sheet of OSB did the job for you so far then you may as well just do that again. It’s not worth spending more unless you want to add strength or value or extend the life of the trailer beyond another 15 years.

I have a 4x8 utility trailer. When I need a floor (say, for hauling a load of topsoil) I just lay a tarp down and have the topsoil dumped. I then bungee the corners to each other and maybe use a second, covering, tarp, and drive home.

If I needed a more solid floor (why though?) I’d just use a 4x8 sheet of plywood.

Without the wood, there is no floor on my trailer, just a center frame piece between the two wheels, and the box frame around the sides.

If it lasted 15 years, I’d say repeat what you did. You might consider marine plywood, but again you got 15 years out of it as is.

I’d use plywood and put a cover of sheet tin on it, glued and nailed around the sides. Has the advantage of not splintering when you slide shit into the trailer, will probably last forever.

Bed liner is a good choice too–I have that in the floor of my van and the only thing that ever dented it was when some idiot tossed a big metal basket (filled with about 2500# worth of metal parts) in there then tried to scoot it instead of lifting it in with the forklift and setting it down in place. Rucked up a spot about 2 inches square and got a blistering lecture from me on proper loading technique.

Ahh, mine has a floor.
Your situation makes more sense now. I’d just throw a sheet of plywood in and replace when needed.


“Best” is subjective, so let’s move this over to IMHO.

I’m with this. 15 years is a good run for the cost of a piece of 4x8 whatever.

(I’ve got a little 4x8 trailer with presumably oak boards for a floor. Title says it was manufactured in 1946! I think it was made from a surplus Sherman Tank!)