New soil stack and HepvO advice

[Dom]

I have searched the forum for an answer to my problem and it would seem the use of HepvO valves is the way to go(does IMM get commission from Hepworth!?!). What I want to do is install a new en-suite off my first floor bedroom. As it is not possible to route the soil and waste to the existing vented stack, I was looking and installing a new one. This will run near horizontal (with correct fall) under the floorboards to an outside wall, vertically inside the room below and out to a manhole which is no longer used (it used to have a downstairs toilet connected but this was removed). The manhole is connected to another manhole which houses the existing vented stack. My problem is that I do not want to take the stack up into the loft and fit a Durgo as it would have to go up the middle of the wall in the first floor bedroom.

If I fit HepVo valves to the basin and shower can I get away with having a soil stack that does not go any higher than just under the floorboards (actually where the WC joins the near horizontal run would be the highest point)? The Hepworth technical details seem to suggest this is feasible but when I speak to the plumbers merchant, they recommend that the Durgo is used even when HepVo valves are fitted.

Has anyone ever done anything similar and has it been successful? I may need to convince the BCO that it is feasible.

Any advice is much appreciated.

[Rod Hewitt]

[e-mail] (Dom) wrote in news: [e-mail]:

I think it more likely that he gets commission from boiler makers. :-)

Hepworth's advice is that the soil pipe must go up as high as the highest possible water level - e.g. WC rim, bath edge, basin edge, or whatever. The issue is what happens if an appliance completely fills up and the drain is blocked? Upon removing the cap from the soil pipe to address the blocked soil pipe you could get an awful lot of dirty water flowing out of the top of the pipe onto the floor if the top of the soil pipe is below the water level in the appliance. And by then you are talking dirty, not just grey, water.

No need whatsoever for the Durgo.

We have done this (well, the soil pipe is just a bit short of the required height). Bath, WC and basin. Two HepVos (and another for the basin in the downstairs toilet). Only issue is that it is a little noisier than I would have wished but that is almost certainly due to certain compromises in my plumbing. In the downstairs toilet it is almost totally silent. Other than that, delighted.

Depending on exact situation, the HepVo might not be as easy to fit into, say, a cupboard that has been expressly designed for a conventional trap. However, we have one vertical and two horizontal - all work fine - and the flexibility to choose was very helpful. It even appears that stuff like hair travels through them better than our previous standard traps.

Make sure that you get the correct adaptors angled or straight. They can be awkward to locate. (Jewsons had loads but didn't know what they were.)

It has been suggested that Hep. tech support will even talk to BCO if necessary.

If ever you drop something solid down the basin waste, it is likely to be swished right through and down the drain. It won't sit in the trap (well, what trap?) waiting for you to retrieve it. Don't drop a ring down it!

[Dom]

Is this the issue? My (limited) understanding was that a stack with AAV had to be above the highest water level to allow air intake when negative pressure occurs. So a HepVo valve on the basin would suffice. I have since spoken to Hepworth technical support and told them of my plans. I said that I would fit HepVo to the basin and this would join the soil pipe using a pan connector with pipe inlet. They said that this was feasible and there was no need for a soil pipe 'stub' above the basin height. I have found this

previously posted by IMM which seems to concur. I was thinking of putting a rodding access point on my near horizontal run. Are we talking volcanic eruptions of dirty water through this access point if I ever have to clear an upstream blockage?

Did you have any problems with the BCO because of this?

Bath, WC and basin. Two HepVos (and another for the basin in the