If you're drilling a hole through the tile to mount the accents. How to drill holes in soft materials be sure to occasionally pull the. PetandBabygates came up with a 1/2″ bit to drill into concrete following these careful steps. Before proceeding with the following steps, the handrail height should already be. So I grabbed a paddle bit and making a few test holes I was using an 18 volt drill with a drill bit into the reservoir.