I just bought a new single axle 6x12 utility trailer. The floor deck is treated wood. It's been raining a lot here so it needs to dry out but I would like to coat it eventually. I have some deck coating left over from the house deck.

I've also heard you can coat it with a diesel and oil mix.  

What's worked for you?

Whatever you put on a residential deck, you can put on your trailer. 

If the trailer is new, keep in mind you SHOULD wait until the 2nd year to do ANYTHING with green treated lumber. 

I plan on using the roll on pickup bed liner that comes in the gallon jugs on mine when I put the new bed on.

Porch & Patio Paint


This stuff is MUCH better for walking on than your standard paint.

Since you have time I would surf for a discounted floor paint for the garage or deck or one of the bed liner do it yourself kits. 

After taking a look at some decking I am replacing on one of my trailers the sun and surface rain are what seem to have done all the damage.  There is some underneath damage but overall that would not require replacement probably.

I am currently just sort of repairing it yet again with a bunch of scrap wood I have on hand, dang do I fit the hoarder description at times.

I am working on getting things up and working well, going to mess around with what I have and pick my favorites and sell the rest.

If I keep this one I am messing with the wood on I will replace all wood and coat it like I am talking about.  For now for using it I don't need to buy anything but some of the scraps I have are not in the best shape.  Will safely work for now.

To some extent considering a deckover with a 20 ft deck, and seems some have a 5 ft tongue, so if I bought something new I would just treat the surface of it.

IIRC I used something like this and added sand to it for better grip.  Ben a few years and is holding up just fine. I'll see if I have the paint can in the shop later.

Dbl

I'm not advocating this....but I've heard used motor oil + kerosene is the standard.

It's treated wood... why would you feel the need to coat it with anything?
Around here a lot of the rednecks would use untreated native lumber for trailer decking because it was cheap and then apply used motor oil every few years to help preserve it but your's is treated.
A couple of years ago I pulled up some treated 4x4s that I had put into the ground for deck posts about 30 years before and they were still sound.

Something like that would only work on DRY wood I imagine. Need to soak up said contraband.

All the local cowboys retreat their trailer decks when they do an oil change on their trucks or tractors.  The cowboy who helps me work my cattle has been doing this for years and he has the original lumber on his 32' float.  My 32' float is six years old and I need to replace some of the lumber on it.  Wished I would have known this earlier.

Same reason you coat a treated wood deck. Makes it look better and lasts longer.

Used engine oil works very well! 

Linseed Oil

I've got a flatbed that I made sideboards for and I decided that they would look better if they were black like the bed... wrong!
I used semi-transparent stain instead of paint as I thought it would soak in a bit and not show scuffs, scratches and shallow gouges but after a couple of years there were bare spots all over.
I re-stained them a time or two but it's really kind of pointless as it's a working truck and not a show truck. Should have left them bare .

As far as lasting longer if it's good quality treated wood (and there's different grades or levels/kinds of treatment) it will probably outlast all of us.
My deer towers I built with treated wood that I bought from a yard that caters to pole barn builders... my oldest one is around 15 years old and is as sound as the day I finished it.

Just my $.02. It's your trailer to do with what ever you want.

Cover the wood with 14 gauge diamond plate steel.  I made sure to buy one this way, with no wood.  The AZ sun is unforgiving to exposed wood.  The trailer did not cost that much more with steel.

50/50 used motor oil and diesel.  And no, I'm not kidding.