Deck plywood - what's best to use?

[DJ Jaws]

So my boat has been sitting for a while and apparently not handling weather so well. It turns out that moisture has been retaining in the carpeting and slowly rotting the floor underneath. I know that typically boats rot from the bottom up, by mine is rotting from the top down. I'm still cleaning and removing damaged wood, but it appears that the manufacturer only glassed certain parts of the deck, and relied on the wood to hold up on its own. Kinda weird, I guess they are only made to last so long. Anyway, it looks like I'm going to get away with just replacing the wood deck and a few minor pieces of cleating, and I'm planning on glassing over the whole area and probably either gelcoat the whole thing or maybe some better carpeting.

My question is what is the best kind of wood to use for the deck? Since I'm going to glass it over, can i just use regular plywood or do I need to use Marine plywood, or maybe something else?

 

[Woodonglass]

What boat? Glass or aluminum? Pix?? Most of the members use Ext. Grade plywood. Marine Grade IS the best AND the most expensive. If you encapsulate the wood in resin and or glass and do it well then just about any wood will suffice. As long as water can't get to the wood it will last a long time. If your boat is aluminum then you shouldn't use pressure treated wood. Epoxy seals the best and again is the most expensive. Polyester resin and Chopped Strand Mat is used the most due to it being less expensive. However it's classified as a hazardous material and therefore shipping IS expensive. Working with it is a bit more "Tricky" but not that bad. Some people say it Stinks. Some people have bad allergic reactions to Epoxy. Some just use wood sealer and Paint the wood with Oil Based Paint. You can do it about 10 different ways and get 10 different results. Bottom line is this... If you maintain and care for your boat properly, and keep it covered when not in use, you can almost use bare wood and it will last a good long time. It's abuse and lack of maintenance that ruins a boat in most cases.

Give us some more details and I'm sure you'll get a lot of specific advice.

 

[DJ Jaws]

I have a 1988 Sea Ray 21ft. Unfortunately I don't have any pics right now. However, if the rot extends further than I think it does, this will become a much larger project and I may consider parting it out. For now, I'm just planning on doing some mild carpentry to replace the cleats, and sheet over the deck, then glass is over. I that's what happened, they went cheap on the flooring and didn't glass the whole thing, only the edges. I'm just getting as close as I can to the edges, take out the damaged wood, and then use some construction adhesive to bind it to the edge, and CSM/Resin layer over the entire span. I'm just trying to save a little money if I can use regular or pressure-treated wood versus marine grade wood in the hopes of making this not be an expensive repair. I've already sunk thousands into repairs and I'm trying to make it usable for a few years before maybe trading it up.

 

[gm280]

So many times the boat builders are not concerned with longevity. They are merely churning out boats to make money and close up shop shortly after. And that IS why there are so many defunct boats laying around that we see here on iboats to be refurbished as boating projects. But each project renews their boats to amazing things to behold and use for many many years to come. YES those boats are given new life that is actually better then original. And that is because the new owners want their boats to last and don't short cut the efforts... JMHO!

 

[DJ Jaws]

I'm not really looking to become the next FricoJarretts, but I'm just looking to get some enjoyment out of my investment and hopefully it'll have a little trade-in value in a few years.

So can I use regular sheeting or do I really need the heavy-duty stuff?

 

[BillP]

At a minimum use ac exterior, ab is better but use exterior because it has waterproof glue. Marine grade pressure treated is the best...with epoxy. Otherwise use polyester.

bp

 

[Woodonglass]

Ok Fiberglass boat with rotten deck. Once you get the deck out, your really need to inspect the stringers, bulkheads and transom for rot, If they are bad then you know the story. If they indeed are ok then the Ext. Grade plywood is perfectly acceptable to use as long as you glass it well and install it properly. This will get you started...Fabricating Decks, Stringers, and Transoms

 

[DJ Jaws]

Wow great stuff! Thanks!