Replacing basement bathroom pipes

[modern-man]

Hello, New here, but an old hand at doing my own renovations. I do like to consult with the pro's when I have a new situation, so here goes.

I am gutting a basement bathroom & need to move the fixtures. So I opened the concrete floor. When I checked, the shower (never installed) was pitched way off, and the main branch coming in was also off just a bit. However we have been using the toilet for 25 years without incedent. Here is photo.

I'm going to dig up as much as I can of the main (about half of it's 7 foot length, the rest runs under a finished room), cut it off & start fresh.

My question: Since the pipes were already touching the concrete & adding the proper pitch will bring them up more, is it ok that they be imbeded in the concrete by an inch or 2 (the floor is only 3 inches thick) and should they be treated/protected somehow to de-couple them from the concrete due to expansion contraction?
Thanks
Paul

 

[johnjh2o]

It won't do any harm to the piping but with less than 2" of concrete over the pipe expect cracks to appear in the concert where the pipes are.

 

[modern-man]

Thanks John, that's what the guy at my local hardware mentioned just now. He also said that some folks put some kind of thick metal mesh into the cement to reinforce the concrete & reduce cracking.
Fortunately, most of it will be underneath the bathroom floor. I guess I better use some of that dricore type subfloor to allow air circulation.