Attaching walls to floor

[Redstar]

I want to use a 2x2 frame with 3/4 ply deck and attach walls with a rabbit my question is if my outer skin is 1/4 ply and I want to counter sink the screw heads how much risk do I run of the screws pulling through ??

[KCStudly]

I have used a bunch of #6 FH screws on 5 mm ply (3/16 inch actual) Okoume marine ply (5 equal plys, virtually no voids) and, with the proper clutch setting on my cordless drill, have had no significant problems. When I knew that I would be running the screws in and out a few times, such as for a dry fit up of my ceiling skin, I used little squares of scrap from the same ply as temporary washers. After a couple uses the washers would wallow out and I would make some more, but the base material held good with a single shot. Just don't run them down too hard. Also, I found that I was better off not countersinking the holes in advance. By pilot drilling and then just crushing the FH screw until they were flush, or just barely under flush, I got the best result.

YMMV with different species, grade of wood, or screw size.

[tony.latham]

I use 1/4" subfloor plywood for my exterior walls. The stuff available here is a higher quality than 1/4" AC plywood –no voids and no footballs and is stamped "for moist environments." And it's a few bucks cheaper.



In the photo above, you can see screw heads below the Kreg screw slots. Those are through the 1/4" plywood and into the floor's frame. I don't bother to counter sink and they suck up flush and don't pull through.

Tony

[Redstar]

Thanks for the reply's i'll just go slow and should be fine