3/4" subfloor over slab (barrier between) -- 3/4" hardwood T&G application.

Will 1-1/2" staples be safe to NOT go through to the underside of the 3/4" subfloor (or damage the barrier between the sub and the concrete slab)?

Thanks,
Pete!

Yes, 1 1/2" is what I would go with, ( due to the angle of the fastener...your safe ).

Thank you for confirming! That's what I'm going to use -- just wanted to be safe.