I need to secure a flange to some newly poured sand/topping Quickrete we poured in our basement bathroom. This new slab is just 1 3/4" thick. I'll be securing bolts (and drilling) into the foundation concrete below the sand/topping slab. I have a brand new 19V cordless hammer drill that should do the job.
I'm concerned that if I hammer drill into the sand/topping it will just fall apart before I even get to the foundation concrete.
Are my fears valid? Any tips on drilling through this stuff? Also, the slab was poured five days ago. Am I good to go, or should I let it cure longer?
Obviously, I'm nervous about this. Any tips would be appreciated.
The sand topping should drill pretty easily. Drill on rotary only until you reach the core concrete. Then switch to hammer to finish it. Otherwise, if your hole is close to the edge of the topping, you'll risk a blow out. I assume you are drilling mounting holes for a toilet flange which will be close to the edge of the pipe opening.