Hi, may I ask any builders/plumbers for an opinion on the attached picture. This was installed yesterday to carry waste from an upstairs toilet to the drain.  When the builder came to make the connection he discovered that the toilet had been installed above one of the aluminium ceiling supports below, necessitating the pipework being diverted to clear the obstructing support. When I arrived onsite I was horrified to find that he had used 4 x 90 degree bends, which in my opinion was a recipe for disaster.  I expressed my concerns via my Thai wife but the builder assured my wife that the pressure from above would push out any obstructions from the short horizontal runs. I was still unhappy and asked my wife to ask them why they didn't just use 2 x 45 degree bends, one at the top and one at the bottom with a section of pipe in between, a simpler, cheaper, easier solution eliminating any horizontal runs completely. The builder obviously hadn't thought of this and dismissed my suggestion out of hand (loss of face?) and continued to box in the pipework (but not before I took a picture) so the problem is now hidden from view. For clarification, a 45 degree bend at the top would also have cleared the aluminium support.  Am I over-thinking this, or should I contact the head of the building company to force the builder to re-make the connections as per my suggestion? Any ideas would be appreciated.

I'm not a plumber, nor do I play one on TV.

 

But that looks a nightmare.

 

How would the pipe have been routed if the support wasn't there? If it was a sensible route then I'd have modified the ceiling supports.

 

90^o bends are a problem when it comes to stoppages, and you will get stoppages ???? 

 

Your 2 x 45^o bends would be a sensible solution.

 

Of course, now it's glued it's going to be less than easy to change ???? 

 

 

17 minutes ago, nerjaron said:

When I arrived onsite

too late

45 would be better but what is pictured will work fine...

Just eat plenty of fibre, muesli etc and you'll be fine!

I'm with the builder on that.

However, wait a bit and see how it goes. If it really does cause a problem, it's not a hard job to redo yourself ( or if pants at DIY a different builder ).

Bit pointless stressing about if it isn't a problem.

 

PS. For future reference, the time to do something about it was before it got boxed in. You were paying, so IMO you could have insisted, or had it left unboxed to be redone later.

You know it will be headache at some time in the future. Fix it now!

12 minutes ago, Crossy said:

How would the pipe have been routed if the support wasn't there? If it was a sensible route then I'd have modified the ceiling supports.

I agree, it should be easy to change that ceiling support. If there is a better solution with a different place for the ceiling support, then change that support. 

There are maximum amounts of fall for horizontal sewer runs, Its no more than 1/50, 1cm fall for every 50cm horizontal , otherwise the water flows quicker than the solids, actually causing blockages. 2x 45 degrees would be too much fall.

Photo is not elegant, but It will work.

It will work!

My wife followed the 'worker', definitely not a plumber, doing the piping.   She had to redo most of the drain piping.  This FB post of hers is a crack up ... TIT

 

cut the aluminum support and fix the two ends....

I would try it out...maybe he is right and no problem, I don't know.

75 mm or 100 mm waste pipe ?

 

Many thanks for all the responses - I should have mentioned its 100mm (4") pipe. 

 

The general consensus seems to be that whilst it's not pretty, it will probably be ok so I intend to leave it. If it fails at some point in the future I have enough DIY knowledge to fix it myself. By then of course the pipes will be full of my and my wife's doodoos but at least my welding mask will come in handy for some protection! Thanks again to all.

It's not correct or even close. Im not seeing a vent line off the waste line ( forget about ever using a p- trap) and without one in this configuration you may well have problems with that many 90's in a short run.   They should have moved the ceiling hanger and piped it properly. Not surprising though as rarely is done to any code here for plumbing or electrical.