Noisy soil pipe / messy plumbing

[scotsgraeme]

Hi folks
I've recently had my bathroom redone, and as part of that they replaced a cast iron soil stack with grey plastic. Since that's been done, the noise after flushing is pretty horrible, my guess is it's due to the pair of 90 degree bends at the bottom of the soil stack. Can this noise be reduced by replacing the 90 degree bends with 45 degree bends?

We also had a toilet fitted in what used to be a cloakroom cupboard, and the plumbing for that, as well as the condensate pipe form the boiler are pretty messy, just floating in the air with no support. Is there a technical reason why these could not just terminate into the soil pipe nearest them, neatening things up a bit? Could the horizontal (or almost) soil pipe be fastened to the floor (should it be, or is it loose for a reason?)

I'm asking here, as given the other corners cut by the bathroom guys I don't trust their opinion, and before I go asking them to rectify things, I'd like to know where I stand. See the attached photos.

Thanks for any advice

 

[John D v2.0]

90 degree bends are not acceptable at the base of the stack, they must be long radius bends ie rest bends due to the high speed of the falling water. Alternatively you can use two 45s.
Looks like they made a pics ear of it, maybe they don't expect their work to be checked against building regs.
Other pipes can enter the soil pipe although not within the splash zone at the bottom.

 

[Hugh Jaleak]

Good god, did they arrive on horseback? That is pretty awful work, whole lot needs taking out and starting again. Bends are frowned upon in the wet part of the stack unless absolutely necessary, and as John has pointed out, in that situation, 45's should have been used, not 90's. The pipework should also be adequately supported. What was the arrangement of the original cast soil pipe?

As for the condensate and wastes, could be a lot neater, that is not the work of a plumber, it is the efforts of a bodge artist. Get them back to rectify it.