looking for a decent plywood for a crawlspace "floor"

PVC boards won't rot, that be my solution.

I'd be tempted to cover the dirt with black plastic sheeting and lay down cheap 1/2" or 3/4" plywood on top of it. You could try sealing the plywood, but with the flooding I think it's a lost cause. Just plan on replacing it every 5 years or so.

If termites could be a problem I'd just go with the plastic sheeting :-).

Fredd Wright wrote in news: snipped-for-privacy@googlegroups.com:

Your plywood will rot, even if bugs don't eat it first.

If you have lots of money, Markem's suggestion of PVC boards would work. Otherwise, you're probably better off just leaving it alone.

John

If it's a very dry crawlspace, perhaps PT ply, preferably something that's rated for ground contact. Other than that, PT 2x4s for stringers with PT ply on them. Even if it's dry, the humidity may be quite high, hence the PT.

PVC, ply will rot. Trex or something similar.

I'd like to lay some sheets of 4x8 plywood (or other material) on it to make a surface suitable for crawling on or putting things on. It will lay right on top of dirt. It doesn't have to look good as it's in a crawlspace in an unfinished basement. I't won't be exposed to rain but there will be some moisture coming up through the dirt. Also, i'm probably going to hose it off occasionally. In addition, every 5 years or so it will be underwater for a day or two when we get a hurricane as they usually flood the basement. Can anyone recommend something that will last but not cost me an arm and a leg? Again, i don't care how it looks.

While it has been mentioned in passing, I think the strongest negative for putting wood, any wood product, on the ground in the crawl space is the attractiveness to bugs, particularly termites. In fact if you do put wood down there it may void your currently have a termite contract. (Read the fine print)

I was under a house a couple of weeks ago, that someone had actually poured an area of concrete under the house to provide an area exactly what you area for exactly what you are talking about.

Properly prepared, a slab of 2 to 3" thick would seem to me to be sufficient for a storage area under the house. You would not driving cars on it and you will not be storing any heavy equipment.

That would probably be best. Actually the crawlspace starts out as concret e and then after 2 or 3 feet, the concrete stops and the rest is dirt. Kin d of like the original builders just gave up. I like the idea of concrete but i've never done it before and it seems like a lot of work. Plus, i wou ldn't know how. Is there another type of material that wouldn't attract bu gs?

That would probably be best but it seems like a lot of work and i have no i dea how to pour concrete. Others mentioned PVC. Would that attract bugs? I imagine not since it's plastic. Not as solid as the concrete but it may serve for my purposes. How hard is it to apply concrete if you've never d one it before?

How about 1ftx1ft concrete paver stones of blocks, like you would use in a garden path? Just lay it down with some mild scraping for leveling, and you're good to go.

I'm certainly not a termite expert but I wouldn't expect them to be a problem in a crawl space unless the house was already infested.

Why not just put down some pavers?

Or level the area and lay a sheet of rigid foam insulation on the ground, and PT plywood on top of that. Stake it down with 10 inch spikes driven into the ground so it doesn't float away in the next flood.

Don't bet your house on it - - - - There have to be termites in the area - but they don't need to be a problem on your property now to be a problem when you leave wood on the ground.

In San Francisco CA in the 50's and 60's it was common practice to put down a 2" to 3" layer of concrete in the crawl space of the victorians. It was called rat proofing.

CP

This is the solution that the OP wants, and the only viable one for cost effectiveness and longevity.

When I build a house with a crawlspace foundation, I always pour what we call a "mud slab" (3 - 4" of un-reinforced concrete) over the exposed ground in the crawl space.

(I also put in French drains as part of the drainage plan, but that is another matter)

Inexpensive, effective, can easily hold most yard items for storage, makes for easier access, cuts down on mold, mildew and smells, and only requires a minimum "finish" and leveling of the surface.

maybe first install a sump

then maybe a layer of large gravel

then marine plywood

then store stuff you do not care too much about as it will corrode in that environ

For crawling, a few planks of 1/2" plywood (exterior) would be useful. For storage, consider that you'd like ventilation around the stored items; I'd try some old pallets, with optional 'wood preservative' painted on (they won't weather, so stain or real paint are a waste). I'm lazy, I just strap on some knee pads and a hard hat when it's time to crawl.

'd like to lay some sheets of 4x8 plywood (or other material) on it to make a surface suitable for crawling on or putting things on.

Good ideas here. I have to admit that when i first posted, i wasn't thinki ng about the termite angle. I like the idea of the concrete but i have a f eeling i'd make a mess of it as i don't know what i'm doing. However, the p aver idea sounds interesting. I priced it and the pavers cost the same per square foot as 3/4" plywood and they would last indefinitely. However, tha t's also something i've never done. Do i just level the ground and lay the pavers on top letting gravity keep them in place or is there something els e i need to do to secure them?

Use pressure treated ply and termite concerns go away.

Around here - central Florida - a sheet of PT 1/2" x 4' x 8' is about 25 bucks. That's about $0.78 sq/ft; pavers run from about $2.00 sq/ft up. An exception is a 12" x 12" x 1 3/4" concrete "stepping stone"' that is $1.31.