drain and copper lines for a new tub install, ideas...

Hi everyone,
The tub filler and tub have been ordered - now the tough part.
I am replacing an old fiberglass tub with a new freestanding tub and I have some concerns for the copper and drain lines.
Attached are images of the space and ideas on how and where to run. The drain looks pretty basic, just needs to be set lower into earth and run the drain pipe to the center with slope factored in.

The drains are my real concern. The exit the wall about 15" on the toilet room wall and need to be moved into the slab and near the center. In the pic I have an idea of waht it should do. But I am a novice and would appreciate good advice. If I run the lines along the wall its close to the exterior wall and dont like unstable slab there. The lines running in with the drain pipe is only one rip out of slab.
1. Any reasons why this is not the way to go?? better solution?
2. tips on refill with cement over the copper and drain lines.

The tub is acrylic and weighs 120lbs, my plan was to lay the tub on top of the porcelin tile floor vs cutting around. I read a recent thread on this issue, and think this is the way to go. The tub is oval in shape.

Thanks again everyone...
Chris

correction: the copper hot/cold lines are my concern.
chris

New Tub Layout


# 1 WHEN YOU EXTEND DRAIN YOU WILL NOT GET PROPER FALL ON PIPE AS
THAT HAS ALREADY BEEN SET BY THE EXISTING DRAINPIPE, THE BEST YOU CAN POSSIBLE GET IS TO RUN YOUR NEW DRAIN OVER FLAT!!!
BUT THATS NOT THE WAY ITS SUPPOSED TO DONE, AND MAY CAUSE DRAIN PROBLEMS!!!

#2 THE COPPER UNDER THE FLOOR SHOULD BE RUN IN SOFT COPPER AS YOU DO NOT WANT ANY COPPER FITTINGS UNDER SLAB!!!

MACPLUMB

MASTERPLUMBER & MASTER DRAINMAN

macplumb,

thanks for the input.
My idea was to dig downward and set the p trap lower a couple of inches so when I run to the center of the new tub I will have regained my slope. Currently the top part of the drain pipe is about flush to the slab(the old tub had a deck and sides so no reason to be below slab)

Soft copper meaning flexible, makes sense. Is it normal to pour my backfill cement right over copper? At the big orange box, they suggested runnign the copper pipe in foam sleeve so the pipe is protected from gravel/rocks from my backfill dirt befor cement is poured. is this a good or bad idea, makes sense though?

Any other input?
chris

Copper should never be in direct contact with cement. a Chemical reaction will lead to pinholes.

Jimbo, what do you suggest for protecting the copper?
rubber foam sleeves??
chris

Ihave used armorflex(foam sleeves)then wrapped it with 10 mil plastic.
Use type L soft copperwith NO solder joints under your cement.
Make sure pipe protection comes above cement.

You think PEX is an option for this 4ft run, alot of flex, possibly no wrapping since its use for infloor heating. Alkalinity in the soil a problem?

Chris