Mmmm. Impact driver.
//www.diynot.com/forums/posting.php?mode=reply&t=138885 is the link to reisser screws.
Thing is, he doesn't want to screw into chipboard or ply. He wants to screw THROUGH ply into softwood. Granted, the Reisser says for softwood and hardwood too. But they wood (arf arf) say that wouldn't they.
Electric tools to drive screws are great. But with caution. I've sheared screws in half with them.
You want a pilot hole in the boards (and joists, if you get that far), and a clearance hole plus countersink in the ply. It takes a while, but it's the best job, and this is your house. Line lots of holes up to do at once, so you're not changing bits a lot. Set a low clutch setting on your electric screwdriver, and finish by hand for a really good job I think. When yoiu do the last turn or two by hand you get a really good feel for when it's tight enough.
If you're trying to get away without drilling I predict a couple of things:
You'll shear some screws in half, leaving half a screw that is very difficult to get out. And you might not be able to leave it if it threatens to protrude.
When you're screwing close to the edge of the board it'll split sometimes. And you need to screw close to the edge of the board so you don't have any raised, er, edges.
Of course, all this is just my opinion and a bit of experience with this particular thing.
But it's your house, you might be living there for the next 30 years. Don't you want to do it once, and right?
