OK to use exterior treated plywood for deck?

[chris0061]

I've posted several times here on my deck and have a plan and all the stuff ordered except the wood. Someone laid a floor in there but then quit and its only half inch. My question is, would I be messing up if I put in 3/4 treated exterior plywood from Lowe's in at 32 bucks a sheet verses 3/4 marine plywood at 70 bucks a sheet?

 

[jcsercsa]

Re: OK to use exterior treated plywood for deck?

I've posted several times here on my deck and have a plan and all the stuff ordered except the wood. Someone laid a floor in there but then quit and its only half inch. My question is, would I be messing up if I put in 3/4 treated exterior plywood from Lowe's in at 32 bucks a sheet verses 3/4 marine plywood at 70 bucks a sheet?

Yep just make sure you coat it with 3 to 4 coats of something, I used polyuerthane on mine !! John

 

[cbavier]

Re: OK to use exterior treated plywood for deck?

Yep just make sure you coat it with 3 to 4 coats of something, I used polyuerthane on mine !! John

Yup done mine two years ago like this right over the top of the original deck because It got a hole in it. No stringer rot or wet foam so thought hey what the heck. To be able to check the condition I screwed a piece to an old treee stump in the back yard. I just checked it yesterday and it looks good as new and even the screw looks good. I thought it might rot. I used decking screws and only replaced the back half up to the front of the back to back seats. Then matched the carpet the best I could with Deck Carpet from Home depot. I probably got $80 in the whole thing.

 

[chris0061]

Re: OK to use exterior treated plywood for deck?

ok great, I got 3 gallons of epoxy resin on the way so I'll give the bottom two coats and then coat the top, lay the mat then coat again. Thanks guys,

 

[likefish]

Re: OK to use exterior treated plywood for deck?

i did lots of research on the subject as well and ended up using marine plywood. I bought mine from a local bot repair place because it was "kiln dried" i didnt have the time or patience to allow mine to dry and have heard MANY TIMES that if the PT is still wet the epoxy/ poly will not saturate it for good protection.

If you can allow it dry as long as possible. THe yard where I bought it uses it in all of there restorations. They have been around for about 15 years and have a good reputation for quality work. I trust there opinion and experiance.

Good luck with your project! Check out mine at: http://forums.iboats.com/showthread.php?t=297511

 

[NSBCraig]

Re: OK to use exterior treated plywood for deck?

Oh yeah if your using epoxy you way good.

Poly and so mat would work too, if you wanted to save some dough.

 

[boat1010]

Re: OK to use exterior treated plywood for deck?

When I redid the deck on my boat I just used regular plywood. The place that I looked it up on line said not to use Marine plywood because the fiberglass rosin does not stick to treated wood as well as non treated wood. So I put the resin top and bottom and it seemed to work well. That was about 5 years ago.

 

[Mark42]

Re: OK to use exterior treated plywood for deck?

There is a lot of mis-information and mistaken beliefs about PT ply in boats. The APA (Engineered Wood Association) recommends PT plywood in boats and there are a few publications by them confirming their tests and promotion of PT wood in boats. And there are tests by the APA that show resin sticks very well to PT plywood even at 90% moisture (sopping wet).

But read it straight from the horses mouth here and make your own decision:

http://www.glen-l.com/wood-plywood/boatbuilding-plywood.html

http://www.glen-l.com/wood-plywood/fiberglass-plywood.html

Also, ask Bond-o about how well pressure treated plywood has been holding up in his boat for the last 10 years.

3/4" is probably over kill. Go with 5/8 if the 1/2 was not strong enough. Plus the glasswork will add more rigidity to the floor.

 

[sschefer]

Re: OK to use exterior treated plywood for deck?

I've posted several times here on my deck and have a plan and all the stuff ordered except the wood. Someone laid a floor in there but then quit and its only half inch. My question is, would I be messing up if I put in 3/4 treated exterior plywood from Lowe's in at 32 bucks a sheet verses 3/4 marine plywood at 70 bucks a sheet?

Using exterior ply is fine. Using 3/4 vs. 1/2 can cause problems if you don't remember you're a 1/4 higher than you were before. Anything you intend to fit back in will need to be trimmed.