Jon Boat Floor

I have a Alumacraft 1648 NCS Flat Bottom. I am going to put a floor in using advantech plywood. My questions is do I need the foam board insulation under the plywood? The advantech can easily support itself between the ribs. Thanks

Yes.
The foam is for floatation in case your boat flounder.

Ok I figured the foam in the seat and under the deck would be plenty

You can never have too much.
Also if you put foam under the floor you could remove some from in the seat and use the space for storage.

An Alumacraft 1648 NCS already has a flat tin floor, does it not?

I put extruded styrofoam board under the 1/2 ply floor in my 1648. I think it is stiffer when hitting waves. Definitely worth the money.

-CN- said:

An Alumacraft 1648 NCS already has a flat tin floor, does it not?

Click to expand...

If his model is the same as my 2016 one then it does not. The NCS MV versions do but not the flat bottoms for some reason.

curt2564 said:

Ok I figured the foam in the seat and under the deck would be plenty

Click to expand...

They will. It is not necessary just keep in mind that the weight of the floor will count towards the overall 1,000 lb capacity.

But considering the low cost and weight of foam board, I would add it. It will aide flotation in the event you capsize or take on too much water plus that foam board is rigid and will add support between the ribs for whatever lays on top of it. For my boat (same model) I used a 1 & 1/2" thick sheet of 4x8 foam board, which was about $30, and topped it with 3/8" rubber stall mat from Tractor Supply. The mat is not structural at all but it laid over the foam and ribs feels super solid. Keep in mind with my setup the foam offers no additional flotation aide as it is not help in place by a fastened down floor.

Advantech is NOT plywood but rather oriented strandboard. 7/16” OSB is heavier (15-20%) than 1/2” plywood and although it is made with exterior resins it will not withstand repeated soakings - it is intended to be used where moderate exposure to the elements exist, as in framing a house. Do yourself a favor and use a sanded panel, like BCX. Yes, it will cost you more initially, but the weight savings, durability (paint & edge seal) and improved fastener holding properties will be worth it.


Sent from my iPad using Tapatalk