[Hyns]

I dismantled an old shower on a concrete slab. I plan to tile the bathroom floor. What do I use to cover the floor drain before I tile the bathroom? Can I just pour mortar down the hole?

[ballengerb1]

I'd stuff an oil soaked rag down into the hole about 2" below the new surface, then butter on top of the rag with thinset to smooth out the surface. I am assuming you are totally eliminating the shower all to gether

[Hyns]

Yes I am eliminating the shower in the guest bathroom to make room for a cabinet. Never used the shower. I have removed the tilefrom the shower and the rest of the floor. The hole will be covered by the tile. What is the purpose of the oil soaked rag?

[ballengerb1]

It will better seal out sewer gas than just a thinset patch which will/may crack over time.