deck construction

[kmax45]

I am a first time boat owner and first time boatdesign.net user. I just bought a 1986 wellcraft american 192. I have decided to redo the floor/deck. I am fairly mechanicaly inclined. the existing floor has plywood with blue marine carpet on it. My plan is to rip up the carpet and cover the old (rotting) plywood floor with new plywood and then either put new carpet or paint or fiberglass. I will be using the boat for lots of fishing and some water sports and family activities. I would appreciate any help on where i should begin and any ideas for flooring.

p.s. i would like to go the most inexpensive and efficient route, being this is my first boat and i dont know how long she will last

Thanks!!!

[Zappi]

You definitely dont want to "cover up" the rotting plywood.

[PAR]

Use the "search" thingie at the top of the page. This topic has been covered many times, with globs of useful information available.

Quarter century old boats generally suffer from a few common ills, a soft sole (floor) is one of them. The usual causes are, carpets trapping moisture between it and the substrate beneath, fasteners and other penetrations into the substrate that have permitted moisture to get in and bedding (caulk) that has failed (dried out) and let water enter.

Unfortunately, when the soles get soft, it's usually a sign of bigger issues, such as rotten stringers and other elements of the sole support structure. Placing a sheet or two of plywood over the rotten sole, will not fix your problem, though it may feel firmer under foot for a while. Replacing a sole is a dirty job, but one that can be done by a reasonably handy person, which you seem to be.

It involves literally removing the old sole (cutting it out) then attaching new material, of course assuming the stringers can support and hold fasteners, then bonding everything back in with 'glass.

Carpet is a big problem with boats. It works so long as it stays well stuck, which it never does, so moisture gets under it and slowly works it's way into the plywood sole, eventually rotting it.

Removing things and replacing things, like seat boxes or pedestals without sealing the old holes or bedding the new pieces properly is another common death nail for a sole. You be surprised how much rain water can enter through a #10 screw hole that doesn't have a screw living in it any more, because a seat was moved.

In any case, I would recommend you access what you want from the boat first. By this I mean, will you keep it for several years and fish the crap out of it, or will you clean it up, make some repairs, have a little fun, then sell it.

The long term solution is to rip out the spent sole and replace it right. The short term fix is slapping some plywood down over it and hoping to find enough good wood under it to fasten it to.

The down and dirty fix will net you a couple of years, but you've not fixed anything, just masked it for a while. Eventually the stringers and sole will rot out completely and it'll just turn to mush, taking the new plywood cover with it.

The proper repair will last another quarter of a century or more if you use epoxy. This is what I would do if I wanted to have several seasons of hard use without worrying little Johnny is going to step through a new soft spot.

[rasorinc]

I would only add to the above--if you are going to re-carpet over new plywood then use pressure treated ply. It does not rot from moisture for decades. Be sure to let it dry before covering and if you have a choice use the arsnic treated ply.
You can get P.T. plywood in CCX plugged, touched and sanded which is an exterior grade but less than Marine ply and it is OK for soles. CCX ply has some knot voids and marine does not so do not use it for structural purposes. If you epoxy the PT ply as Par suggests then you have the best moisture protection you can get.

[kmax45]

wow guys, thanks alot! I would say i will probably be happy if i get 2 or 3 seasons out of the boat and then sell it. The floor is actually not in awful shape right now. I just happened to notice one or two small soft spots. Other than that, it seems pretty solid. I was just looking at this nautolex deck dot flooring. Does anyone know anything about that? I am afraid of putting carpet back down with all the fishing I'll be doing. Are there any other options for a floor that will be easy to maintain and not look like crap? Also, i tried to search the forum for any other "how to's" on new floors but i couldnt find much. Do i definitly need to use marine grade plywood or is there an inexpensive alternative? Thanks again for all your help

[PAR]

Don't use pressure treated lumber. The resins we use to bond things down on boats doesn't stick very well to the chemicals used to treat the plywood.

If you're looking for just a few seasons of fishing, then slap some regular exterior grade plywood down over the old stuff. Not partial board or OSB, regular exteior plywood.

Also don't use the typical "deck sealers" like Thompson's or other similar products. First off they don't work very well and secondly the moisture repellent used is wax, which makes bonding or painting very difficult.

Prime and paint the plywood really well, especially the edges. Lots of primer, lots of top coat. Then use a textured paint to give you some good fraction in all the fish guts.

Truck bed liner coatings are about the best non-skid you can apply, but it's not as cheap as texture added to paint.

Use fairly light plywood, like 1/4" or 3/8", you don't want to add too much weight.

[timothy22]

Nautolex was big back when I worked in boatyards. Several cheap stock boats used it because application was quick. We loved it-guaranteed repeat business. None of us would use it on our boats because it did just what carpet does-trap moisture under it and rot the deck. Also looks very scruffy after a few years wear and exposure. Do it PAR's way. It takes longer, but it works better, and the word about carpet and other coverings has sort of gotten around and savvy buyers of used boats are leery of it.