Plywood for flooring

[Douglasdzaster]

I’m getting ready to put the new floor in the jon boat I’ve been working on.
Its been many years since I’ve purchased any plywood so I’m kind of lumber dumb.
I ask my wife to pick up a sheet and make sure it’s not treated. She came home with RTD sheathing. Is this ok for aluminum? I’m going to glass both sides and edges.
Also I measured it and it’s 3/4” (I ask for 1/2”). She said they all where weird sizes. Lol
Im like do the math bless her heart.
What do you tin boaters say is thick enough to run across the ribs of a 16 footer?
Thanks everyone. Every time I have a question I can come here and it’s been a while because I had to put off the boat and do other things. Y’all have helped me with the trailer. Then the corrosion i found in the bottom which took me several hours of sanding. Now I’m ready to put a floor in and I’m excited to go fishing.
After I use it for a while I’m going to pull the motor and flip it to remove the bottom coating that’s starting to peel off and seal all seams and rivets then apply new coating. I’ll be asking about products then. While the motor is off I’ll probably go ahead and redo the transom then I’ll have a new 1983 16/52 boat.
All the advice is greatly appreciated.
A before picture of the floor.

 

[FuzzyGrub]

I had to look up RTD plywood. Looks like it is replacing CDX in home constuction. It is rated for mild moisture contact.

I wouldn't use it, even glassed in. 3/4" is probably overkill and heavy. Use foam between the ribs for flotation and floor support. If you have to use plywood, go 1/2" exterior grade, ACX. If the foam sheeting is the same thickness as the top of the ribs, you can go with a thin sheet of aluminum. I went with 0.040" thick aluminum over foam more than 10 years ago. Still going strong.

 

[Douglasdzaster]

I had to look up RTD plywood. Looks like it is replacing CDX in home constuction. It is rated for mild moisture contact.

I wouldn't use it, even glassed in. 3/4" is probably overkill and heavy. Use foam between the ribs for flotation and floor support. If you have to use plywood, go 1/2" exterior grade, ACX. If the foam sheeting is the same thickness as the top of the ribs, you can go with a thin sheet of aluminum. I went with 0.040" thick aluminum over foam more than 10 years ago. Still going strong.

Thanks for the information. I looked it up and saw it wasn’t ground contact pressure treated but I still didn’t have a good feeling about it. The bench seat in the middle of the boat was removed before I got the boat so I have a bigger gap between the ribs there. I was thinking about foam for that reason. I’m using rivnuts so the floor can be easy to remove after it gets wet. It’ll be under cover when parked. I plan on keeping it dry after all the work I had to do from the previous owner using treated plywood and moisture stuck underneath. It was a mess. Debris under the ribs in the channels. Rusted hooks , bolts, screws Plastic baits etc.

 

[FuzzyGrub]

Are you actually laying fiberglass or just sealing with epoxy?

 

[airshot]

Why all the time and trouble to glass in the plywood?? You can find 5 ply exterior grade good one side in 1\2" thickness, used thatbin my 12 jon with no issues. The foam between ribs is a good idea. My jon had a number leaking rivets and actual holes rubbed thru the bottom from dragging it over sand and rocks. Repaired mine with
" leak stopper" roof patch for exterior surfaces. Dries clear, this stuff is tough!! Availiable thru Home Depot and Tractor Supply stores. Did the inside and outside of my aluminum jon boat over 5 years ago, paint is worn off but the leak stopper has not leaked a drop and the boat still gets dragged over sand and rocks. Just used rustoleum enamal for a top coat after sealing the hull. A coat of paint with some traction grit sprinkled on the plywood floor. Floor is still solid !!

 

[LDUBS]

I agree that 1/2 is all you need. I also had to look up RTD ply. What I read is that it is exterior and moisture resistant (I'm guess the glue is waterproof). Instead of glassing, consider saturating with epoxy. Not sure what floor cover you are going to use. If vinyl, wrap the edges and the ply will be protected for a very long time.

 

[Douglasdzaster]

Are you actually laying fiberglass or just sealing with epoxy?

It’s just fiberglass resin.

 

[Douglasdzaster]

Why all the time and trouble to glass in the plywood?? You can find 5 ply exterior grade good one side in 1\2" thickness, used thatbin my 12 jon with no issues. The foam between ribs is a good idea. My jon had a number leaking rivets and actual holes rubbed thru the bottom from dragging it over sand and rocks. Repaired mine with
" leak stopper" roof patch for exterior surfaces. Dries clear, this stuff is tough!! Availiable thru Home Depot and Tractor Supply stores. Did the inside and outside of my aluminum jon boat over 5 years ago, paint is worn off but the leak stopper has not leaked a drop and the boat still gets dragged over sand and rocks. Just used rustoleum enamal for a top coat after sealing the hull. A coat of paint with some traction grit sprinkled on the plywood floor. Floor is still solid !!

I’ve already used Total Boat epoxy for the inside. No leaks but had previous repairs that where looking suspicious. I’ll have to remember to leak stopper when I redo the bottom.
Thanks for the reply.

 

[Douglasdzaster]

I agree that 1/2 is all you need. I also had to look up RTD ply. What I read is that it is exterior and moisture resistant (I'm guess the glue is waterproof). Instead of glassing, consider saturating with epoxy. Not sure what floor cover you are going to use. If vinyl, wrap the edges and the ply will be protected for a very long time.

I got caught up watching a guy do several boats and he always coated the plywood with fiberglass resin on both sides and edges. Now y’all have me wondering if I should have purchased epoxy instead. Lol
The floor is going to be easily removable in sections and each section will have marine carpet with a moisture barrier on the back. It will be attached to the plywood with canvas snaps. I’m going to be able to disassemble everything for cleaning and drying.
I’m going to a lot of trouble but after what I had to do because of what I found when I removed the old treated plywood I’m making sure every thing stays clean and dry.

 

[dcbz]

I got caught up watching a guy do several boats and he always coated the plywood with fiberglass resin on both sides and edges. Now y’all have me wondering if I should have purchased epoxy instead. Lol
The floor is going to be easily removable in sections and each section will have marine carpet with a moisture barrier on the back. It will be attached to the plywood with canvas snaps. I’m going to be able to disassemble everything for cleaning and drying.
I’m going to a lot of trouble but after what I had to do because of what I found when I removed the old treated plywood I’m making sure every thing stays clean and dry.

If it were my boat and I wanted to keep it for several years, I would order 1/2" marine grade plywood which can probably be ordered from Home Depot or your local lumberyard. If I only planned on keeping it a few years, I would just use exterior plywood. Marine plywood's layers (plies) are glued together with waterproof glue so the plywood will not delaminate when exposed to water. It is important to remember that with all plywood, even marine grade, the wood will still absorb water and rot if it is not coated. I would recommend coating both sides of the wood and the edges with a penetrating epoxy. Jamestown Distributors, and I'm sure others, have a product specifically for such a job: Penetrating Epoxy Sealer
You can paint over the epoxy sealer after it cures if you choose to do so. There are several topside boat paints that would suited to an application such as yours.

 

[Douglasdzaster]

If it were my boat and I wanted to keep it for several years, I would order 1/2" marine grade plywood which can probably be ordered from Home Depot or your local lumberyard. If I only planned on keeping it a few years, I would just use exterior plywood. Marine plywood's layers (plies) are glued together with waterproof glue so the plywood will not delaminate when exposed to water. It is important to remember that with all plywood, even marine grade, the wood will still absorb water and rot if it is not coated. I would recommend coating both sides of the wood and the edges with a penetrating epoxy. Jamestown Distributors, and I'm sure others, have a product specifically for such a job: Penetrating Epoxy Sealer
You can paint over the epoxy sealer after it cures if you choose to do so. There are several topside boat paints that would suited to an application such as yours.

I appreciate your advice. I’m on a tight budget on this one. The materials I do have I’ve collected over time. If I could I’d do the project completely different. Aluminum flooring everything. Lol
I planNed on keeping it for as long as possible when I first got it.
I’ve been using it as I go and after several fishing trips i discovered I could use something bigger for drifting. That being said I haven’t been in the river yet. Not until Im able to do the bottom because of the many hazards. Then I’ll know more about the future. Right now I’m trying to get back on the water.

 

[Skunked again]

Heed the above advice.
In my opinion, if you want the wood to last longer, stay AWAY from carpet!
Why? It holds water.
I’ve had both vinyl and a “liner” (think truck bed liner). In various boats. Both shed water, neither hold water. Neither where slick when wet, both cleaned easily. Blood from both me and fish, coffee, soda, all cleaned easily.
For my current boat, I put in EVA foam. Time will tell. First time using it.

 

[FuzzyGrub]

Marine Grade Plywood Info

 

[LDUBS]

I got caught up watching a guy do several boats and he always coated the plywood with fiberglass resin on both sides and edges. Now y’all have me wondering if I should have purchased epoxy instead. Lol
The floor is going to be easily removable in sections and each section will have marine carpet with a moisture barrier on the back. It will be attached to the plywood with canvas snaps. I’m going to be able to disassemble everything for cleaning and drying.
I’m going to a lot of trouble but after what I had to do because of what I found when I removed the old treated plywood I’m making sure every thing stays clean and dry.

I've read on other threads, I think, that using fiberglass resin by itself isn't the best choice. But I could be remembering wrong. Anyway, it is done and If it were mine I honestly would not overthink it or worry about it. Guys have been using ply floors in boats for years. The ply will need to eventually be replaced, but will likely outlast your carpet. Put your floor covering on and start using the boat. The fact you are storing it under cover makes a huge difference too.

I agree marine ply is the ultimate. However, if it were mine, I would use exterior ply and save the $$. Both use waterproof glues. The big difference is marine play does not have voids.

In case you are still deciding, I will say that marine vinyl is highly recommended for durability, maintenance ease, and protection. I have it on my ply floors (which have no treatment) and no issues. Other posters here with a lot more experience swear by it. I suspect it is more $$ than carpet, but have not checked.

I think you are smart to do the floor in a way it can be pulled up and put back down if needed in the future.

 

[FuzzyGrub]

My only plywood boat hangs from the ceiling, at camp.

 

[Douglasdzaster]

I've read on other threads, I think, that using fiberglass resin by itself isn't the best choice. But I could be remembering wrong. Anyway, it is done and If it were mine I honestly would not overthink it or worry about it. Guys have been using ply floors in boats for years. The ply will need to eventually be replaced, but will likely outlast your carpet. Put your floor covering on and start using the boat. The fact you are storing it under cover makes a huge difference too.

I agree marine ply is the ultimate. However, if it were mine, I would use exterior ply and save the $$. Both use waterproof glues. The big difference is marine play does not have voids.

In case you are still deciding, I will say that marine vinyl is highly recommended for durability, maintenance ease, and protection. I have it on my ply floors (which have no treatment) and no issues. Other posters here with a lot more experience swear by it. I suspect it is more $$ than carpet, but have not checked.

I think you are smart to do the floor in a way it can be pulled up and put back down if needed in the future.

Thank you for the input. I checked on the vinyl on Amazon and it was expensive. I read in the Q&A someone said buy from Defender Marine so I went to their website and it’s a lot cheaper. I may be able to return the carpet , the tool to install snaps and get the vinyl for just a few more $.
My only question is does condensation or any water ever get between the vinyl and the wood? What type of adhesive did you use?
Sure would be a lot easier to get the catfish slime off the vinyl.

 

[Douglasdzaster]

My only plywood boat hangs from the ceiling, at camp.

View attachment 112592

Nice!

 

[Douglasdzaster]

Heed the above advice.
In my opinion, if you want the wood to last longer, stay AWAY from carpet!
Why? It holds water.
I’ve had both vinyl and a “liner” (think truck bed liner). In various boats. Both shed water, neither hold water. Neither where slick when wet, both cleaned easily. Blood from both me and fish, coffee, soda, all cleaned easily.
For my current boat, I put in EVA foam. Time will tell. First time using it.

I found the vinyl on Defender Marine website. If I return the carpet and the tool I bought for the snaps to Amazon I think I can swing the vinyl.

 

[Douglasdzaster]

O.K. I’m looking at Nautolex vinyl. Can anyone tell me if I have to use their adhesive or can I save a few $ on another adhesive?
EDIT: Well the vinyl got shot down by the admiral. I had looked back at the price of the carpet now. She reminded me that it was marked down and I had a $20 coupon. And she wants carpet anyway. This is my first aluminum but I’ve had a few bass boats and no how to take care of carpet so we’ll see how long it last. It’ll be connected with snaps anyway so if it turns to $*/+ I’ll unsnap it and do something different then.
I really appreciate all advice and knowledge being shared with me.

 

[LDUBS]

O.K. I’m looking at Nautolex vinyl. Can anyone tell me if I have to use their adhesive or can I save a few $ on another adhesive?
EDIT: Well the vinyl got shot down by the admiral. I had looked back at the price of the carpet now. She reminded me that it was marked down and I had a $20 coupon. And she wants carpet anyway. This is my first aluminum but I’ve had a few bass boats and no how to take care of carpet so we’ll see how long it last. It’ll be connected with snaps anyway so if it turns to $*/+ I’ll unsnap it and do something different then.
I really appreciate all advice and knowledge being shared with me.

I suspect carpet is used more than any other floor cover in small boats. Enjoy.

BTW, I can't answer about the vinyl adhesive because I didn't install it. It came with the boat.