Aluminum floor and deck thickness

I'm planning on starting my decking and flooring project on my tracker 1542 next weekend, the only thing I haven't decided on is what thickness I need for the aluminum flooring and the decking.

I'm building a deck from the mid bench to the front bench, and then a deck on the back bench. I have the frame work all laid out but need to figure out how thick the aluminum floor needs to be. The only problem with this is I don't know what thickness to go with that will be strong enough to support me and another person, and this problem applies to the flooring I want to install in the middle of the boat.
The plan is to install a floor over the ribs in the middle of the boat, I'd place closed cell foam down between the ribs for the width of the boat then rivet the floor to the ribs. I also have to figure out if the foam will be enough to support the floor space between the ribs.

I plan to use the aluminum sheeting instead of wood to save on weight unless wood is better?


any suggestions would be greatly appreciated!

.125"

I used .062" for mine, but, I was able to get away with using material that thin because I also had side panels for the gunwales, and it was all welded together to form one big tray.

I recently bought a couple 4' x 8.5' sheets of .090" from a metal & scrap yard. Each sheet weighed like 41 lbs. It was $2.25/lb. This was much cheaper than ordering off any of the internet sites I had looked at.

My plans for those sheets are to have a livewell, baitwell, and steering console made. I was thinking about 0.063" for the floor when I get that far. From what I've read on here, if you put closed cell foam, wrapped in plastic between the ribs, the .063" should work just fine.

A regular 4x8 sheet of 0.063" should only weigh 28 lbs. or so if my math is correct.

Seems like I remember reading that a 4x8 sheet of plywood weighs about 25 lbs. per quarter inch of thickness. (i.e. a 3/4" sheet weighs 75 lbs.)

My 1648 consists of two different thicknesses of aluminum. Everything is .063" except for the ribs which are .090". I'm 240 lbs. and when I step on the .063" benches, there isn't much flex, but there is a little. I would think that you if braced a deck every 12-14 inches, you'd be good to go with the thinner stuff, but I'm pretty new to all of this.

My boat is .125 floor. .100 deck, and any hatches are .125.

Man, y'all guys are going overkill on the flooring (1/8") That's a lot of added weight. As stated, the 4x8 sheet of .062 is about 27 pounds. You can double that weight for 1/8" (.125")

On a typical johnboat, I think there is adequate cross bracing for .062" material, especially if you put foam board underneath, this will support the weight much better. And once you rivet the floor to the ribs, that also acts as a stiffener. Also, if you use a press brake, and have the gunwale edges bent, that will act as a stiffener. And if you do like I did, and use side panels, you can either rivet or weld them to the floor panel, and that will also make the whole thing more rigid.

I can see using the 1/8 for hatch covers, decks etc...in fact, that's what I used on all my hatch covers. But for flooring and gunwale panels, the .062" is plenty adequate, especially using the methods described above to stiffen everything up.

True, I DID use .090" for the floor under the front deck on my Triton, but that's because I have the weight of 2 fuel tanks and batteries on that area, it's a lot of weight per sq ft, so, I wanted something a little heavier than .062" but not as heavy as 1/8"

I myself dont like the feeling of the floor moving when you walk on it. My first boat had .063 flooring, it sucked IMO. it was just a flat sheet riveted to the ribs, piss poor design, all the rivet holes lobbed out over the years from the excessive flexing. I really could of downsized my current floor to .100.

Bugpac said:

I myself dont like the feeling of the floor moving when you walk on it. My first boat had .063 flooring, it sucked IMO. it was just a flat sheet riveted to the ribs, piss poor design, all the rivet holes lobbed out over the years from the excessive flexing.

Click to expand...

That must have been a factory designed floor. Like I said, if it's done RIGHT (and apparently it wasn't in the case you describe) there shouldn't be any flexing.

My jetboat has .062" floor, haven't had any of the problems you describe. But then again, I built it, not the factory.

I had an identical floor in my old 14 foot dura craft, and I used that boat for commercial oystering and crabbing. Once, I had 22 bushels of oysters in that boat (at 60 lbs per bushel) as well as 2 people. True, we were about an inch from going under at the bow, but....all that weight and abuse never affected the integrity of the floor.

Yes factory design, and it sucked. I think for most guys, if your just dropping it in on the ribs and riveting it down, a little up size doesn't hurt anything, I also am not 160 lbs, that would make a big difference as well. If you have tools to incorporate some bends etc, then thinner material is more than enough.

I used .090. I think its goldie locks....just right. ;-)

Thanks for the input guys, I'm gonna go with 0.1 for the decking and then 0.063 or 0.083 for the flooring as I figure the foam I have is very dense and does not compress that easily, it's also 1/8 of an inch higher then the ribs, so I'm thinking if I lay the sheet over it and rivet it down then the foam will push up on it enough to stop it from bending under my weight or a friends weight. I'm just tired of tripping over the ribs when walking around on the boat plus since I want to put in a fore and aft deck this gives me some more foam storage to hopefully help keep it floating if I ever take on way too much water.


probably a long shot but does anyone know of any aluminum supply places in NJ? I'd prefer to drive and pick it up myself/dig through scrap/unwanted/discounted pieces if they have them.

what type of foam are you using between the ribs, and where did you get it?