[NoCo]

The problem with this design is it relies on having strapped down(from the frame) rocket boxes. This is why i want to build one that my cooler sits on too. The steapped down cooler will hold it from wiggling.

 

[MT4Runner]

NoCo, IMHO 3/4" is overkill. 5/8" would do it.
I like your idea to span under both coolers.
Another idea would be to laminate together two pieces of 1/4" plywood so you get even more plies (both strength and stiffness and minimize voids/weaknesses) in a thinner, lighter panel. I did this for the massive 36" x 42" stern cross hatch in my dory and it's bomber stout.

Your plywood floor is suspended on its "strong" axis.
Your plywood side decks are spanning their "weak" axis (long fibers of the wood face should span the supports, not across them). Have you stood on top of the wood while suspended and if so how much flex did it have?

And if it doesn't flex, you could go with a thinner ply running the correct direction to save weight.

 

[cupido76]

Your plywood floor is suspended on its "strong" axis.
Your plywood side decks are spanning their "weak" axis (long fibers of the wood face should span the supports, not across them). Have you stood on top of the wood while suspended and if so how much flex did it have?

Isn't one of the main points of plywood that each layer grain is perpendicular to the ones above and below?

 

[MT4Runner]

Yes, but the top and bottom skin see the most stress (top in compression, bottom in tension).

The plies aren't very strong in tension across the grain, somewhat strong in compression across the grain.

If you're using 3/4" plywood and each layer is 1/8" thick...it's basically like having 5/8" strength with 3/4" weight.

 

[cupido76]

^^^ good to know.

Does that mean I should be selective with my plywood when I buy it to ensure the grain is the way I want? I'm guessing it varies?

 

[MT4Runner]

Nah, 4x8 sheet pretty much always runs the 8’ length.

 

[Bobthegreat]

Here is what I got. It holds three rocket boxes, plus everything else.

 

[Bobthegreat]

 

[NoCo]

Nice neavertail bob

 

[gdaut]

Bob, what is that decking and where did you get it? Seems like a great material for floors and beaver boards.

 

[Bobthegreat]

It’s a kennel and chicken coop floor. Dura slat.

 

[aman]

Only suggestion is to leave as little space as possible between your floor and the boxes or rubber. Preventing a foot entrapment issue is your biggest concern. So design the beaver board or captains floor to be the similar to width and length of the space the floor will be suspended above. I have about a 1.5" clearance between my beaver board and the rubber and a 0" space between the back of the beaver board and the dry box of my front and rear bays. Same with my captains floor. 1.5 space between the sides near the rubber and 0" where it butts directly up against the cooler or drybox of the bay.

 

[caverdan]

I’ve just completed my first drop floor build (PHOTOS ATTACHED), which we will put to the test next week on Gates of Lodore. Big thank you to everyone who contributed to this and other conversations on the topic. Very helpful. I chose pressure treated plywood coated with two layers of spar urethane. Probably would have gone with marine grade plywood if it was more readily available, but time was limited. Also added side boards along both tubes and applied traction strips, like you would find on a skateboard. I like the extra weight that it adds and I think it makes our entire rig a much safer system. We’ll see if that all holds true next week. Thanks again everybody. View attachment 59729 View attachment 59730 View attachment 59731 View attachment 59732

I loaned a cargo floor to a friend and he rigged it with straps through the holes like you are showing. He ended up breaking my floor at the holes. The correct way to rig it is to use one continuous rope or webbing threaded underneath the floor from hole to hole and up to the frame or D ring and back through the hole. Then under the floor to the next hole and repeat.

 

[Bobthegreat]

There is no concern with foot entrapment. Once all the gear is in place it get covered with a gear cover.

 

[MeetOutside]

That looks like a lot of area that has been cut and drilled out. Have you stood on top of the wood while suspended and if so how much flex did it have? View attachment 59730 View attachment 59731 View attachment 59732

[/QUOTE]
Mine is solid with all the holes. 3/4" pressure treated plywood.

 

[MeetOutside]

I loaned a cargo floor to a friend and he rigged it with straps through the holes like you are showing. He ended up breaking my floor at the holes. The correct way to rig it is to use one continuous rope or webbing threaded underneath the floor from hole to hole and up to the frame or D ring and back through the hole. Then under the floor to the next hole and repeat.

Thank you for the insight. My rigging worked quite well on a recent Lodore trip, but I can imagine how running webbing underneath would provide additional support. Always appreciate improvements to the system.

 

[MannyAvs]

I’ve just completed my first drop floor build (PHOTOS ATTACHED), which we will put to the test next week on Gates of Lodore. Big thank you to everyone who contributed to this and other conversations on the topic. Very helpful. I chose pressure treated plywood coated with two layers of spar urethane. Probably would have gone with marine grade plywood if it was more readily available, but time was limited. Also added side boards along both tubes and applied traction strips, like you would find on a skateboard. I like the extra weight that it adds and I think it makes our entire rig a much safer system. We’ll see if that all holds true next week. Thanks again everybody. View attachment 59729 View attachment 59730 View attachment 59731 View attachment 59732

That looks amazing. Can you tell me how you attached the side rails to the frame?

 

[ShotgunBill]

Here is what I got. It holds three rocket boxes, plus everything else. View attachment 59788

Hi Bob, that looks awesome. Just got a new 16' NRS and was hoping to make drop floors and side rail boards. Would you trust Dura Slat for a drop floor in the cockpit? How is the traction? Is it structurally sound to hold a person and a few rocket boxes? This seems like the ideal material for raft boards. Thanks.

 

[Bobthegreat]

Well I am not able to to comment on how this would work for the cockpit. It’s only in the rear for gear.

 

[seydou]

I’ve just completed my first drop floor build (PHOTOS ATTACHED), which we will put to the test next week on Gates of Lodore. Big thank you to everyone who contributed to this and other conversations on the topic. Very helpful. I chose pressure treated plywood coated with two layers of spar urethane. Probably would have gone with marine grade plywood if it was more readily available, but time was limited. Also added side boards along both tubes and applied traction strips, like you would find on a skateboard. I like the extra weight that it adds and I think it makes our entire rig a much safer system. We’ll see if that all holds true next week. Thanks again everybody. View attachment 59729 View attachment 59730 View attachment 59731 View attachment 59732

I'd like to know tto how you secured your side boards. Nice job btw.