A: Greetings, and thanks to you and all my Canadian friends!

Peter, I'm a firm believer in keeping toilet drain lines in place for bathroom remodeling jobs. Toilet drains are usually the largest drain lines in a home at three to four inches in diameter. Moving them (especially on upper floors) usually will open up a big can of worms as you seem to be finding out.

In most cases, floor joists will have to be drilled and/or cut, and usually that may not be possible to meet codes without extra support added. Your idea of building another floor on top of your present floor, while creative, can also pose some major questions for this job.

First thing that comes to mind is weight -- can your present floor support all the weight of another raised floor on top? How about the six to eight inches the floor may have to be raised to fit a large drain, what will happen to your ceiling height, window height, and door entrance to the bathroom? What about resale value effect to your home -- will the raised floor be a turn-off to a potential buyer? What type of permits will be required for the job?

These are serious concerns that you will have to discuss with your local building inspector to see if this job is even possible to attempt.

Now, to your original question. Usually, according to most building codes I have seen, waste lines need to be turned with sweeping fittings like 45 degree bends, not standard elbows. You may be able to install two 45 degree fittings together, to make what's called a "sweep 90," but that does take up more space and must comply with your local codes.

I would seriously rethink your bathroom design to try and leave the present toilet drain in place. Bottom line: meet with your local inspector before you start this job. If it's allowable, and you still insist on moving the toilet, make sure you add up all the extra costs first, so you don't get floored by your new bathroom floor job when the bills come in.