Restaurant toilet problem

[CplSmudge]

Hi people, mind if I share a problem with you all?
Scenario is a restaurant with toilets on the lower ground floor, svp goes up to third floor offices and away into the roof somewhere. 2 cubicles and basins in ladies, 3 connected urinals and 1 cubical in gents. Problem is pans backing up and not clearing. I've seen the gents back up just by having clean cold water poured in from a bucket and thought the problem was air related. I checked with building control about placing a dirgo valve so low in the system and they ok'd it but apparantly it hasn't solved the problem. We've checked the horizontal soil pipe and its clean and appears to fall the right way, so can anyone scratch an idea off their forehead please?

Cheers

Chris

 

[Bernie2]

The problem with a dirgo is its an air admittance valve for releasing a vacuum. You seem to have a back pressure problem not a vacuum problem.

Any poly bags gone down the drain?

I would inspect the outside manhole first off, and work back to wc's.

If nothing, then it could be back pressure which unfortunately you may need to ventilation the drain through the soil pipe. Not easy and got to be outside or joined back into stack above highest fitting. That is of course supposing the stack is vented and not just fitted with another dirgo in the roof space.

Good fortune

 

[CplSmudge]

thanks Bernie, you make a good point re the dirgo valve.

to test that out, can we simply take it off and leave the pipe open for an hour or so to check if the problem still occurs?

The problem has been taxing the locals for months and the pipework has been rodded twice to no avail.

Re your last paragraph, are we trying to create a positive flow into the stack with the additional ventilation, rather than simply allowing air to be drawn in when needed?

 

[REDSAW]

The problem with a dirgo is its an air admittance valve for releasing a vacuum. You seem to have a back pressure problem not a vacuum problem.

Any poly bags gone down the drain?

I would inspect the outside manhole first off, and work back to wc's.

If nothing, then it could be back pressure which unfortunately you may need to ventilation the drain through the soil pipe. Not easy and got to be outside or joined back into stack above highest fitting. That is of course supposing the stack is vented and not just fitted with another dirgo in the roof space.

Good fortune

so your saying it could be due to a 'dirgo' in the upper floors creating mass air intake/.? so it will need investigating the complete stack system.

 

[CplSmudge]

Sorry Redsaw, are you querying what Bernie said or asking me a question?

Chris

 

[REDSAW]

Sorry Redsaw, are you querying what Bernie said or asking me a question?

Chris

yeh, but no but.

saying the soil could be pressurising with air from the upper floors pushing air block from draining toilet in basement.
like bernie says, it needs air out-let not intake in the lower flors, proberbly?

i would try to check the entire stack if poss.

 

[CplSmudge]

ok, I understand. The easy bit's writing it eh? I can't see how we'd get another vent up 3 floors. (That'd be why Bernie said outside, I suppose).
If there is a dirgo valve on the top of the stack, is it any good to remove it?

 

[justlead1]

Hi. If there is a a vale fitted at the head of the stack, i certainly would remove it and monitor results of lower floor performance. If it does the trick extend system to terminate to the atmosphere in the form of a vent. Good Luck