Replacing sub floor

[aaronschaefe]

So I got myself in a bit over my head. What started off as a project to just remove some dated appliances and cabinets turned into a project to replace a subfloor that was pretty much rotted through around the edges. I have my trailer stripped down to the frame, and need to get some replacement plywood to put the floor back in. I think I am leaning toward marine grade plywood, BS-1088. I don't ever want to have to do this again, so want something that might last another 40 yrs.


A local supplier has sheets of Hydrotek and Okoume. Anybody have any idea if one would be better than another for a replacement floor?


Thanks!

[Belegedhel]

Ah, yes, the all-too-familiar tale of an upholstery job that turned into a shell-off!

Well, when my spruce-up job turned into a shell-off, I went with the marine grade plywood at ~$100 per sheet. There are plenty of threads here on the forums discussing the relative merits of marine grade vs non marine grade. Having gone through it, I am of the opinion that if I had to do it over again, I would use plain-Jane plywood and not incur the extra expense of the marine grade. I am told that the glue in both is equally water resistant, the wood in both is equally water absorbant, and the big advantage you get with marine grade is "higher quality" in that it has less voids, more layers, etc. Since I am not actually building a boat with it, I think this extra quality and expense is for naught.

I painted my new flooring on both sides and especially around the exposed grain of the edges with several coats of polyurathane, and my guess is that this will have a much bigger influence on the longevity of the plywood than whether it is marine grade or not. Just avoid anything that is "treated"--not what you want.

Good luck!

[Tony S]

I pretty much agree with above. I use marine fir plywood at about $72 a sheet.
One thing is I was matching up to original and it was closer. I epoxied the edges and then the whole floor after sanding the original ply that was in good shape. I did this to help with even glue absorption when I laid down the marmoleum. Which is one of the methods used. People do debate its merits.

Okoume is the lightest and most expensive especially if you go with European made.

I bought the hydrotec for a boat in my future and decided it was too risky for the hull and went with the Okoume. I will use the Hydrotec for the cabin if I went that route.

Anyway back to your floor. I would stick with one of the firs.

Tony

[68 TWind]

Whatever wood you decide to use I suggest you seal the edges with a good quality epoxy resin. Nearly all of the issues with water start at the edges under the C channel. If you seal the edges plus about 4 inches in on top and bottom you will have done about all you can do to prevent future water issues. I used West System epoxy but there are other brands that equally effective in sealing the wood.

[putback]

There are serious differences in plywood. Number of plys in a given thickness. Core strength. Inner ply wood type. Core voids. On and on. This is an area a lumber yard or independent dealer can really help you out.

[aaronschaefe]

Thanks for all the advice! I will definitely look into sealing up the edges of the sheet whichever type of materials I end up using.