Plywood question?

[mnhunter2]

Is it worth the extra money to buy this kiln dried marine grade treated plywood over the menards treated plywood and I was orginally going to sandwich 5/8 and 1 1/2 foam over a 1/8 steel deck plate but have decided to buy a frame so could I still use the 5/8 or do I need to go to 3/4, it sure was wet but it has really dried ot in a couple of weeks in the shop. Am thinking of spraying the underside with this high density foam product.

[Eric Wettschreck]

I have the regular 3/4" treated plywood I bought from Fulda Lumber on the floor of my house. It's been in there for 4 years now and it's still going strong. Insulating the bottom of the floor will seriously help keep the lower part of the house warm. A small fan will help also.

Notice you're from Slayton. You've probably seen my house out on Shetek.

[norm]

What I did is put 1/2" treated (from menards) on the frame, on top of that is 1 1/2" pink foam insulation, and on top of that for the floor that you will actually walk on I put 3/8" CDX. The floor is pretty darn solid too, the only place where it feels spongy at all is where the 3/8" is warped a little and not touching the insulation.

Another thing if you don't already know, when using green treated plywood you can't use just regular screws with it, the stuff they use to treat the wood will just eat away the screw. From what I understand, the only type of screws or bolts you can use are stainless steel, hot dipped galvanized, or those triple coated type screws.

[hovermn]

I remember hearing the same thing about using proper fastners. Remember a while back when there was a lot of media coverage of decks falling apart and people falling to their deaths or getting seriously injured. For at least a few of them, the problem was the fastners failing because of the green treat.

Thanks for the reminder. I'm probably going to do some work to the floor in the perm. before the snow flys and I would have forgotten about that.

[bobO]

I used 3/4" green treat in our house. 2' on center. and had no problems. You could get away with 5/8" if you went with 16" on center floor joyce. I would recomned using a liquid nails and galvanized screws. there is a lot a pressure when pulling, loading and unloading the house. Use 1"-1 1/2" foam ridge insulation. I would just install the insulation on the bottom of the house in the joyce cavities. Install with a light weight construction adheavsive and some cap nails.Using a high strenght construction adhevsive will melt the foam insulation.