Hello,

I am putting a new tub in my second floor washroom. Old tub drain pipe is too low, about 1.5" and overflow also 1.5" closer to the wall. I think that overflow may be adjusted with corrugated brass pipe I bought (set by os&b) but the real challenge for me is lifting the drain.
My idea of doing it is:
- unsolder the brass pipe coming from tee connector (overflow up, drain on side and this pipe underneath) down to the copper 1.5" which goes down to p-trap,
- put the new brass pipe from the os&b set and solder it at higher level, 1.5" higher than the old one.
If that is OK, how do I hold this pipe in a correct position while sweating (horizontally and vertically)? Is there any trick to do it easy?
Also this 3, 5" brass pipe has a fine thread to be screwed to under the tee connector. Do I have to put any paste or Teflon tape on it?
Is there a better, easier way to do it?

My second choice is
Cut the copper pipe before the p-trap
Connect copper pipe with abs
Dry fit the overflow and the drain plastic pipes on the tub
Put the tub on the floor
Open the ceiling underneath
Dry fit the new p-trap and connect it to the copper pipe
Glue all

Here I am not sure how to connect copper with abs.
The first choice is to solder the copper to abs adapter but in case I can not do it properly
I would connect them with non hub rubber coupling. This is in Toronto and I am not sure if this will be strong enough and if code allows that way (once I close the ceiling there will be no access to it)
Is there any other way?

As for the bathtub itself, it is Maax; model New Town soaking 60/30. It comes with apron and is put on particle board with 2 legs. Do I have to put concrete bedding underneath it and how do I do it. All the length or in few spots, 3 or 4?
Is there other way?
Do I predrill holes for screws going to flange and stud?
Do I have to encore the legs?
Thanks

My idea of doing it is:
- unsolder the brass pipe coming from tee connector (overflow up, drain on side and this pipe underneath) down to the copper 1.5" which goes down to p-trap,
- put the new brass pipe from the os&b set and solder it at higher level, 1.5" higher than the old one.
If that is OK, how do I hold this pipe in a correct position while sweating (horizontally and vertically)? Is there any trick to do it easy?
Also this 3, 5" brass pipe has a fine thread to be screwed to under the tee connector. Do I have to put any paste or Teflon tape
If I understand you correctly the trap raiser's too short and the tub waste's offset by 1 1/2". To remove the old tub unsolder the tub waste from the trap raiser and lift the old tub out. I assume you've already removed the back wall tile and dry wall.
How we set a tub is to first trim the new tub by installing the tub waste and overflow. Then we set the tub bedding in in if necessary. For your offset solder in the flexible tube to the trap raiser and the tub waste and you're in business. Have I missed anything? Good luck, Tom