Working on affixing my T&G subfloor to my workshop slab in preparation for an oak floor. Work has been difficult and I've snapped as many screws as I've driven successfully. I've tried all the usual remedies:
1. Used good screws from McFeely's- no luck
2. Am using a hammer drill to pilot holes
3. Tried different 3/16" drill bits, including Bosch and Tapcon. I'm using 1/4" screws. No luck
4. Tried phillips and square drive bits (screws are universal).
5. Replaced McFeely screws with genuine Tapcon which were 1/2" shorter to limit penetration to 1". This has improved things a little, but still is very random.
The most common issue is stalling of screw or snapping. The concrete is less than 2 years old, and does not have much aggregate, but is fiberglass filled.
I'm almost at the point of using concrete nails and pound away. I thought the screws would hold better. Any ideas?
Bob