Hi Phil, I am not sure what the problem is. Normally in this situation with a bathroom renovation like this the concrete floor around the drain will be opened up with a jackhammer and your drain repositioned to its new location, then re-cemented before a new screed and new floor tiling.

So I am wondering, has your Bathroom Renovator or the Plumber told you this drain can't be moved and explained to you why?

Malcolm.

No, builder coming around tomorrow for first time, as is Class 2 designer (been a rush to get a bunch of class 2 consultants on board for a simple reno). So far all my own investigations. The slab is structural, 275 thick with localised thickened beams over the posts in the carpark. Opening it up would probably be refused by Strata.

I can go look at the original structural details to see how much cover is over the reo - maybe I can get a 20-30mm scabble and do the rest with screed to cover before tiles. It'd be very flat though. Will need a structural engineer to sign off on the detail, and if I'm honest, I'm uncomfortable reducing cover to the reinforcement as below and think it opens up a bunch of risks. I'll run this past them tomorrow for their comment though.

So....are you on a second storey. If so this is important information for this query.

Technically yes, though we have the car park right below us. Car park is ground level.

The information first given was implying that you were in a normal unit on ground level on a concrete slab. How did you go with the engineers?

Depending on the age of your building,

Submit an application to Body Corporate to move the drainage, have moved a number over the years with plastic pipe

Noting you will be upgrading the Body Corporate Drainage by adding a Fire Collar