shallow shower waste trap with HepVo valve?

[robert103]

we are thinking of connecting the bath, shower and basin waste to underground drain that is connected to the pan waste.

all are 40mm solvent weld pipes and concealed in walls and underground.

we have been told to get a shallow top access waste for shower as we will NOT be using a riser kit for the tray.The low profile tray will remain low on screeded floor. Will we need a HepVo valve AND shallow top access waste?

Please see images below:

In pic 1 the waste to left is for the shower which is connected underground to the waste on the right for the pan.

The black waste pipe in pic 1 resting against the pillar is from the whirlpool bath above.

A wall hung basin is to be installed on wall opposite the waste for pan (see pic 2) where the water pipes have been concealed into stud wall.

I have done some reading and it has been suggested that an anti-syphon waste be installed to the basin to prevent water being sucked from the trap. How can this be possible as the basin is higher than the pan?

we will use a drain adapter to make connections underground.

Thanks.

 

[robert103]

by the way this is what we have found so far http://www.wirquin.com/FICHES%20PDTS%20GB/VIDAGES/SLIM.pdf

 

[Titanium Trades]

Hi, an anti syphon is required if the fall/run of the basin waste has no other option but to fall too fast which in turn will suck the water trap away and leave a foul smell though the house...or, if the design of the waste system is in such a way that when you flush the loo the suction from the water travelling at speed (vacum) will cause a loos of seal. Also the shower is'nt going on a riser kit on a solid floor? I take it you'll be chasing the waste into the floor?

 

[Dannypipe]

I've come across it a few times where a basin waste sucks out a shallow shower trap.

A lot of the shallow ones, are fast flow too, as lots of modern shower trays have such a thin lip around them, the water needs to flow away quickly of you could have a flood.

So they do get sucked dry pretty easily. The best thing is the run the shower on it's own leg of pipe to the soil pipe if possible.

Put a HepVO trap in the floor is only OK if you can maintain it, which you won't be able to. What happens if it gets blocked or gets stuck open with a load of washed off hairs? (again seen this - long hair had kept the trap from sealing back, and bad smells were coming into the room).

 

[chris watkins]

The reading you should have done is Part H1 of the Building Regulation which stats that a 50mm water seal is required for shower (unless you are going to use the waterless trap) if you use mechanical devices be prepared for them to fail, then what are you going to do if it is under the shower tray.

 

[lame plumber]

The reading you should have done is Part H1 of the Building Regulation which stats that a 50mm water seal is required for shower (unless you are going to use the waterless trap) if you use mechanical devices be prepared for them to fail, then what are you going to do if it is under the shower tray.

call in some hapless plumber

 

[Howsie]

Don't waste your time.

http://www.ukplumbersforums.co.uk/showthread.php?t=51894

 

[robert103]

please see image above - the work has now been done.

the diagnal pipe is from the bath waste above.

the straight run is for the basin and part of it has been concelaed in the wall.

the connection for the pan is evident.

the waste for the shower will be connected to drain using a 30 degree bend under the bath waste pipe.

Is this all ok?

re maintaining a hepvo valve under tray, the link above for the Wirquin Shallow waste states it can be done from above whether water type is fitted or membrane type so can't see any issues there.

Any suggestions would help.