Bender board installation

[mclay1234]

I'm planning to build a 24'

yurt platform

and have looked at the readily available plans on the internet (such as from Pacific Yurts), but am having a terrible time visualizing how the bender board is installed. Every plan seems to imply it is screwed directly into the edge of the plywood decking, but this seems like it would split the wood. Even if the wood didn't split, I can't see how it would have any structural strength, especially with the typically long spans between beams/joists in most plans. (I'd also like to use 3/4" plywood for the floor and more tightly-spaced joists, which definitely makes screwing the bender board into the plywood problematic). The only solution I can see is to wedge bits of scrap wood between the bender board and perimeter blocking, but there must be a better way? What am I missing?? (My construction experience is currently limited to an outhouse, so my imagination for solving these problems isn't what it should be!).

Thank you for any advice! If you happen to have plans for a 24' deck with 3/4" plywood subfloor, that'd be super awesome too!

[Jafo]

Not sure what you mean exactly here. If you are referring to the skirt on the outside perimeter, these are just strips of pressure treated plywood (I forget the thickness off the top of my head) and they bend naturally like most plywood does. The purpose really isn't structural. It is something for the lattice to butt up against and for the side cover to lay against. All screws, etc go through the skirt and into the underlying structure of the deck.

[mclay1234]

Yes, that is what I meant. My concern is in all the plans I've seen the screws for the skirt/bender board go into the side of the plywood rather than joists/beams. If I was using 2x6 decking I wouldn't be as concerned; it's the screwing into the side of plywood that seems mighty risky, structural or not. The setup just seems rather floppy.

[Bob Rowlands]

OSB is also used for the banding. OSB doesn't split. But it DOES fall apart if it is exposed to wet and sun. So, just paint it.

As for a bigger meatier substrate for the skirt to butt into, back out the bottom of the T@G subfloor overhang with scraps of 2x.

[Jafo]

Originally Posted by mclay1234

Yes, that is what I meant. My concern is in all the plans I've seen the screws for the skirt/bender board go into the side of the plywood rather than joists/beams. If I was using 2x6 decking I wouldn't be as concerned; it's the screwing into the side of plywood that seems mighty risky, structural or not. The setup just seems rather floppy.

The bender board doesn't hold any weight really. Most screw the sidewalls to it mainly just to keep it tight against the structure.

[Pacific Yurts]

Typically when the platform is built using plywood, it is 1-1/8" thick, so screwing into the edge of it provides a strong and secure attachment with no issues. We also recommend adding a bead of caulking along the cut edge of the platform before attaching the drip edge, which will add to the strength of the attachment and seal it against air and water infiltration. When using 3/4" plywood for your platform subfloor it is a good idea to drill pilot holes prior to screwing the drip edge onto the edge of the platform to minimize the chance of splitting.

[Bob Rowlands]

1-1/8th t@g proper installed is fantastically strong. Moving those sheets is a workout.

Once installed it's the king of subfloor.