soil waste pie

Hello I intend to fit a new ground floor toilet in my early 70's house which has a concrete slab as the ground floor base, which will involve inserting a new soil pipe connecting to the existing set up. I am assuming that in doing this I am obviously going to breach the DPM. So two questions...

Hello, Some advice please I have a plastic push and fit 110mm soil pipe just installed. I am slightly concerned as the joins are inside the wall. I think it is much better have a one solid pipe straight through the wall and through a cavity wall as if it happens to leak it be either on outside...