Hello folks,
I thought I would share my experience with insulation on the floor. Following the generic Benroy plans, I used 1 1/4" deck screws and fender washers.
I had a lot of trouble with break through. Now, I have a 1/2" floor. People with 3/4 inch floors might have no trouble at all with 1 1/4 inch screws. Or maybe it is just that some people have a lighter 'trigger' finger <G>
For my part, I found it much easier to back the screws out and use 1" screws instead--worked much better. If you are using 1/2 inch ply for your floor, you might consider moving to 1' screws if that is the way you attach to the floor.
Ciao,
Jim