If you plan on laying the pine on top of the old wood, it might be alright. I don't think that I would want to put pine down in place of the apitong. It might work, but whether you are talking about rubber tires or track, you will have a lot of weight on the deck. I haul some military trucks, etc., on my step deck from time to time. I would rather have something with a track than a wheel due to the displacement of the weight using a track. I have 12" centers on my step deck and I would be apprehensive about using pine unless I put it on top of the old wood. I might be more inclined to use sheets of plywood rather than pine until I could afford the apitong. Neither will last all that long. The apitong on my trailer is 1 1/8" I believe. Do you plan on taking up the old wood before putting someting else down on your trailer?

Yea, I have to take off all the old wood. Its all broken and rotten. I really don't have another choice but to take off all the wood. I just bought this trailer and need to get it on the road asap. It's a 94 Fontaine 48x102, fixed spread, AirRide, Dump Valve, 22.5LP, 36 inch ride height. I really wanted a 53x102, but got this one pretty cheap. I figured the ride height was sweet it being on 22.5's, so I jumped on the opportunity.

Using pine that thick will raise your deck height. If you use 2" it might work for you. That is going to be a lot of extra work. If the pine is already treated you might make it work longer by treating it again in about 6 months. It is not cheap reflooring a step deck. Mine is 53' long.

The lower deck height may help you. Your post reminds me that I need to call a guy I know who has owned a lot of open deck equipment. He also has a sawmill.

Glad I can help someone out. lol...
I really need to get this whole re-decking thing figured out. I honestly don't want to use pine. I don't trust it, but if I can use it for a year for any stepdeck load, I guess I'll have to do it. Can't really beat the price down here for Top Choice 2" x 6" x 16' #2 Prime ACQ Treated Lumber for $8.97 per plank.

What are you cross member spacings? Are you doing general freight or anything specific? It would be my inexperienced guess that if you could lay 2 sheets of plywood (having each layer staggered) it would be stronger than pine. If you want to treat it you can do that also.

Anyone have an opinion on these woods: poplar or ash.. Anyone have any experience with any of these types of wood?

I can tell you for a fact that anything heavy on fir or pine alone, will fall through both. IF you choose to patch the holes in the trailer with pine......I would suggest going one step further and covering it (the entire deck) with 1" marine plywood as well, like Gman suggested. If you sprayed the entire top of the plywood with linex, you could run it for a couple years and save up the money to do the deck right.

Ash is used to make baseball bats....it has some good points....but it also has its bad points.

Thanks for your info. You don't think the marine plywood will flat out break/snap when 40K+ lbs rolls over it?