decking

[dbrew]

in the next couple weeks i am going to start a restoration on a 20' grumman my question is can i use pt plywood or should i go with regular plywood and just seal the heck out of it. i havent found any marinegrade plywood so i am just thinking of going to home depot and just buying some plywood and outdoor carpet, i dont want to put that mutch $ in it but also i dont want to have to do it all over in a few years.
thanks

 

[robert graham]

Re: decking

Of course Marine Plywood would be the best, but it's expensive. Second choice would be Exterior Plywood. I built an Exterior Plywood transom for my canoe and put several coats of Urethane on it and it's held up great for many years. I believe that any carpet you put on the decking may hold the moisture in and cause it to degrade, but the carpet would protect from UV light, so maybe you break even on that. Good Luck anyway!

 

[samm835]

Re: decking

You definitly need Pressure treated wood. I don't know the exact difference between marine vs. pressure treated other than price, but if you don't use treated you will be replacing it within a year or so. Even if you treat it with something, good luck with your project. I replaced my carpet in my 24ft about a month ago, I went online and found that Home Depot had the best Marine Carpet price out there. You can definitly buy the outdoor carpet cheaper, but I wanted something a little more plush.

 

[dbrew]

Re: decking

what about the aluminum joists do i need to put a barrier between the wood and the metal i have heard that the pt lumber will eat at the aluminum

 

[rickdb1boat]

Re: decking

Yes, you need to provide a barrier between the wood and the aluminum. Most time Deck Joint tape is used like in the link below. You can also buy this at heating and A/C companies under the name of Cork Tape.

http://www.pontoonstuff.com/pontoon-boat/94-pontoon-deck-sealant-pontoon-accessories.asp

 

[ezmobee]

Re: decking

I would not use PT anywhere near an aluminum boat. The corrosion is causes is NO joke. I'd go with properly sealed marine or exterior ply.

 

[nikogto]

Re: decking

Not too mention, but marine grade plywood is very smooth and that makes for the carpet glue and carpet to lay down much nicer. I would use marine grade, that's the only way to make it last long enough.

 

[Huron Angler]

Re: decking

No PT lumber in aluminum boats...period. t's just not worth the risk of corrosion in my opinion.

I did mine with ext grade 3/4" sealed in epoxy resin and that's what I'd recommend.

Unless you can afford marine grade of course, but then you'd just buy a new boat.

 

[Jeep Man]

Re: decking

No PT lumber in aluminum boats...period. t's just not worth the risk of corrosion in my opinion.

I did mine with ext grade 3/4" sealed in epoxy resin and that's what I'd recommend.

Unless you can afford marine grade of course, but then you'd just buy a new boat.

What he said. Do it this way and you can't go wrong.

 

[seldomseen]

Re: decking

I'd go with Marine. 10 years ago I used Home depot exterior 3/4 inch plywood in a 32 ft alu. Marinette that I have since sold. I painted the end grain 5 coats but that cockpit deck rotted in 3 years. It was exposed to the weather .I had it docked in a freshwater lake.

 

[Reg312]

Re: decking

Anyone ever try PVC decking. Sure would keep the weight down and I bet you could still glue carpet to it?

http://www.thehardwarecity.com/products/Genovations-Pvc-Decking/5524624

 

[skinnydipper]

Re: decking

Sorry I did not see this earlier.
I have redone three pontoons from start to finish.
I would definitely use marine grade plywood, (I did not once, and it crapped out in a few years.)
I would not carpet(retains to much moisture which holds water and rots the plywood), I would use Marideck or some similar product.
I have older wood framed furniture and had to use spacers under it to keep it off the floor to keep it from rotting. If you have the newer rotomolded stuff if may not make a difference.

 

[fishrdan]

Re: decking

There are different types/grades of "marine" plywood. Pontoon decking is a CCA treated plywood that's safe for use with aluminum, it's not the ACQ treated stuff that's bad for aluminum. It's expensive and shipping is not cheap though.

http://www.restorepontoon.com/pontoon/pc/Pontoon-Plywood-Decking-c17.htm

 

[PGFISHER]

Re: decking

Anyone ever try PVC decking. Sure would keep the weight down and I bet you could still glue carpet to it?

http://www.thehardwarecity.com/products/Genovations-Pvc-Decking/5524624

PVC is just about rot proof but sunlight will degrade it. If you use PVC be sure to cover, paint, seal or somehow protect it from direct sunlight, or you will get a powder effect on the surface.

 

[5150abf]

Re: decking

Remember the deck wood is part of the boat structure, it is what gives the boat alot of its torsional strength so make sure you bolt it down good and butt the pieces really well, screws can work loose and sheer so use elevator bolts.

 

[KStoon]

Re: decking

Not much $= do again in a few years. Use proper wood=more $= don't do it again very soon. I'm facing the same dilemma. A local lumber yard can order in marine plywood and it was $85 a sheet last year. I know, vs. $25-$35 a sheet that's alot. Most guys seem to be getting at least 10 years on the marine grade plywood so that's $425 to do my 20'. Regular plywood seems to get 3 - 5 years. So $175 now and with figuring in inflation $220 or so in 3-5 years thats $395 plus twice the fasteners. The added plus is i get to do the work twice! It's a pretty easy choice in my book. When I try to chinch out on something it usually costs more in the long run vs doing it right the first time. :redface: