I am installing 3/4" solid prefinished maple through my townhouse and the first floor is a concrete slab. The slab is exactly 30 years old this year.
So, last night we used a Hilti low-velocity gun (rented from the depot) to shoot the plywood down into the slab. On the highest velocity with the strongest powder shots (red "5"), most of them went in completely(I'd say around 85%). So, we've got around 20 or so that are sticking up anywhere from like 1/16" to 1/4". (with one board being particularly crabby, I think it's a certain area of the slab that is harder than the rest)
So, my question(s)
#1: how to get out the ones that are sticking up (I have been told grind them off, but grind with what... a grinding wheel attached to drill? or some other tool? any idea how much effort this would take?)
#2: Could we try to hammer what is left of the plywood fastener into the slab? My instinct says no, but I figured I would ask.
#3: If it turns out that we can't get enough fasteners into this one cranky board for it to hold appropriately, should we try to drill with a masonry bit and then screw the board down into the slab?
Thanks for reading and any information you can provide! Any help is greatly appreciated )