I am installing a tub to existing plumbing, but it's on a concrete slab. We've jackhammered the concrete so that I have enough room underneath to put in the drain and p-trap, but am I going to have to buy the tub, set it in place, hook up the plumbing and then remove it to replace the concrete?

speedball1

Hi Minno, When a slab is poured the cement men leave us a square hole where the trap sets so we can connect the tub and trap. This hole is called a "dap out". We do not cement the trap back under the slab in case we have to service the trap or open up the tub shoe. We leave it open although some contractors have filled the bottom of the hole with roofing tar to cover the earth, but it's not necessary. As a rule the hole runs about 14" by 14" but could be 12"x 12". If you have jackhammered out a large portion of cement the tub sets on, then patch the slab but leave yourself a dap out. Good luck, Tom