One for the experienced boys!

[Avatar]

Alright guys - I have a job I am on where the customer has an internal stack in the bathroom.

The only thing is we have a very low waste outlet on the 'bath/shower' unit which means it is 2-300mm below the toilet outlet. It looks to me that the toilet 'cross flows' up the bath pipe when flushed.

is there any reasonable fix for this? The boss is at 90 degrees to the bog outlet and not directly opposite it . . . Would lowering the boss help? Although I might not be able to do this due to the floor being tiled. Boy, I did warn them to order the unit early so I could check it for potential installation problems, because this one is a beauty!

The unit I am fitting has a like a mini shower trap in it which would not take much to flood with **** - something I wish to avoid!


Thanks on advance for your help guys.

 

[SimonJohns]

Boss connections should have a different level for each connection.
I would also be checking the discharge of the stack to make sure all of the waste is evacuated and there is defiantly no blockage

Could you possibly pick up the stack lower or in a different location so that this doesn't happen

And then finally if you sure everything is good and there is no other option. A hep valve will prevent any back flow. But this shouldn't be used to cover up a poor installation. Get it right first time and there's no call backs

 

[PlumbBobBob]

i would fit something like a hepvo valve

 

[stevetheplumber]

not sure what youmean by mini trap all traps to soilpipes have to be 3 inch deep seal traps or hepvo this is regardless of what comes with the unit

 

[Avatar]

The trap is from China and is only 50 deep in total. Seal depth is halfthis at best!

It does sound like an hep trap may help other wise don't know.....

 

[mountainman]

There are low profile water traps that have the same hydraulic properties of a deep seal trap.
They look like an elongated shallow seal bath trap.

 

[Simon F]

Building regs Part H, 50 mm minimum trap seal for bath or shower
(that is the water seal not the total fitting height)
can be reduced to 38mm when emptying into a grate

 

[mountainman]

But the low profile extended trap has the same hydraulic properties of a 50mm conventional trap, and what about a hep waterless trap, is it unacceptable in uk plumbing systems because it doesn't have a water seal?

 

[Simon F]

just making the point that a shower does not need a 75mm water seal

 

[Avatar]

I will post a picture of the trap if i can as it is truely tiny and I have never seen anything like it before.

The job is fitting a steam unit- 2 grand of shower, massager, built in radio, whirlpool bath, the works ect . . . Replacing similar unit that was odd size that could only be got in china.

The bloody waste outlet is probably only 100mm off the floor - nice one!

I may have to go the way of a hepvo valve as it is a dodgy, bodgy bathroom and nothing had been done properly.

Thanks again.

 

[lambchop]

Any chance of dropping the waste lower down the stack i.e. room below (if bathroom is on first floor and the boxing allows you to do this). I came across this last year and was lucky enough that the stack was in the downstairs storage cupboard). Rock and a hard place mate, put it in your quote what your doing, putting the custard in the picture verbally. They may forget that converstaion later

 

[so-solar]

Hep VO trap or a dry trap is the easiest remedy!