Small bathroom plumbing with macerator

[Leigh Florence]

I have a small bathroom which originally had a sink, shower and toilet running through a macerator. Because it was so noisy i asked the plumber to remove the sink and shower. He did this by teeing in shower and sink pipes to the outgoing macerator waste pipe underfloor before it entered the soil pipe. Soil pipe within 2m of macerator. After it was done i complained about the noise the sink was making when flushing so he fitted a Durgo valve which made the noise stop. However, one day when flushing the toilet the trap in the shower was blowing out water. I complained and he fitted another durgo valve in the shower waste pipe (just before shower). A few days later the sink started blowing out water from its trap even though already had a Durgo. It happened after two people used the shower and toilet. Most of the time it doesn't happen, but has now happened twice. My feeling is that he should have run the shower and sink directly to the soil pipe rather than teeing into a pressurised pumped out pipe (of the macerator), he said wouldn't make much difference i would still get the same problem. But i don't see how. I need to solve this problem what can i do? Please help.

 

[Jim Goodenough]

My feeling is that he should have run the shower and sink directly to the soil pipe rather than teeing into a pressurised pumped out pipe (of the macerator), he said wouldn't make much difference i would still get the same problem.

Yes I reckon that should sort it - you're right!

 

[Leigh Florence]

Yes I reckon that should sort it - you're right!

Thanks. he has not got much room to play with when accessing soil pipe ie about 50cm to 1m section, would it make any difference the order of the outgoing pipes or the distance apart? Ie i was thinking if macerator hole further downstream better as no chance of going back up sink, shower holes?

 

[rpm]

Couple of Q`s,
What size is the pipe from the macerator to the soil stack? (22/32/40mm)
Do the shower and basin pipes join to this pipe separately or do they come together first and join as one?
Are you sure it was Durgo valves and not perhaps one way valves?
For how long was it ok before this started?

 

[Leigh Florence]

Couple of Q`s,
What size is the pipe from the macerator to the soil stack? (22/32/40mm)
Do the shower and basin pipes join to this pipe separately or do they come together first and join as one?
Are you sure it was Durgo valves and not perhaps one way valves?
For how long was it ok before this started?

They join separately. The basin just before the macerator outpipe goes underground. And the shower joins underground before goes through the last two joists. I'm 100% certain they are both Durgo valves. But i do not know the size of the pipes but am almost positive they are not 22, so 32 or 40. It all happened very quickly once all three items being used. Toilet had been out of operation so after couple of days after that working with solids going through it, water/air started coming out of shower trap. Durgo valve fitted to shower, a couple of day after heavier usage started coming out of sink.

 

[rpm]

They join separately. The basin just before the macerator outpipe goes underground. And the shower joins underground before goes through the last two joists. I'm 100% certain they are both Durgo valves. But i do not know the size of the pipes but am almost positive they are not 22, so 32 or 40. It all happened very quickly once all three items being used. Toilet had been out of operation so after couple of days after that working with solids going through it, water/air started coming out of shower trap. Durgo valve fitted to shower, a couple of day after heavier usage started coming out of sink.

Thank you. If no problems with the shower & basin draining on their own I`d be inclined to think problem is within the soil stack therefore 6L of pressurised slurry water is causing a back pressure forcing air/water back up the shower/ basin pipes. One way valves will stop this problem.

 

[Leigh Florence]

Thank you. If no problems with the shower & basin draining on their own I`d be inclined to think problem is within the soil stack therefore 6L of pressurised slurry water is causing a back pressure forcing air/water back up the shower/ basin pipes. One way valves will stop this problem.

Thank you where would one way valves be put? Before the Durgo valves. Why is it happening in the stack, why isn't it going up the holes before reaches the soil pipe if holes are there enroute? The sink durgo valve cannot be removed easily now, although shower one can. When you say it is forcing air/water back up, isn't it possibly pushing slurry back up too?

 

[Jim Goodenough]

It could be the boss/connection of the waste pipe to the soil stack, if this was poorly made i.e. ragged edges left on plastic pipe, maybe slurry has built up and starting to cause back pressure.

By the way is the soil stack vertical where the waste joins?

Is this a multi tenant property? Could another tenant have made alterations to the soil stack?

 

[Leigh Florence]

It could be the boss/connection of the waste pipe to the soil stack, if this was poorly made i.e. ragged edges left on plastic pipe, maybe slurry has built up and starting to cause back pressure.

By the way is the soil stack vertical where the waste joins?

Is this a multi tenant property? Could another tenant have made alterations to the soil stack?

No it's horizontal running along my bedroom floor just servicing me before goes outside. The waste pipe funnelling all three attaches to the side of it.

 

[Jim Goodenough]

You mean the soil pipe is horizontal, it should have a slight fall (slope downwards in direction of flow)?

Can you post a pic(s)?

 

[Leigh Florence]

Yes it does have a slight fall. Sorry all underground no pic. Posting this query because praying don't need to take up floor and separate pipes out. Sorry i thought you thought it was vertical on side of house. It has a fall through the floor before goes outside. But it's only in total about 2.5m across the bedroom, alongside a joist, and out.

 

[Jim Goodenough]

When was the macerator installed?

Is the soil pipe running under the floor 110mm (41/2")?

 

[Leigh Florence]

When was the macerator installed?

Is the soil pipe running under the floor 110mm (41/2")?

Yes that is the size of the pipe. Macerator new, hardly used installed six months ago then had nightmare with cistern leaking (don't you remember my other thread!) that was fixed last week. At the same time shower removed from macerator. Now everything being used and now this problem!

 

[rpm]

Thank you where would one way valves be put? Before the Durgo valves. Why is it happening in the stack, why isn't it going up the holes before reaches the soil pipe if holes are there enroute?

The sink durgo valve cannot be removed easily now, although shower one can. When you say it is forcing air/water back up, isn't it possibly pushing slurry back up too?

The separate pipes from the shower & basin will be diverted in the direction of the outlet with a swept Tee https://www.google.co.uk/url?sa=t&r...90_1114.html&usg=AOvVaw1zZKpP4WYkIMnue_XZ5JgP
So the slurry water from the macerator goes past the holes (as you call them) then the back pressure usually forces air back to the point of least resistance ie the shower. It would have to be an extreme problem for slurry to back flow to the shower.

 

[Jim Goodenough]

Why was a macerator used? How difficult would it have been to install the soil pipe to the WC?

 

[Leigh Florence]

The separate pipes from the shower & basin will be diverted in the direction of the outlet with a swept Tee https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&cad=rja&uact=8&ved=0ahUKEwi26JmhjvHZAhVLlSwKHZz-DOwQFgisATAJ&url=http://www.ipsflowsystems.com/products/abs/fittingsmm/plain/swept_tee_90_1114.html&usg=AOvVaw1zZKpP4WYkIMnue_XZ5JgP
So the slurry water from the macerator goes past the holes (as you call them) then the back pressure usually forces air back to the point of least resistance ie the shower. It would have to be an extreme problem for slurry to back flow to the shower.

And what if a swept T wasn't used? So i think you are saying that a non return valve (one in basin, one in shower) is my best bet. Can the durgo valves be left in?

 

[rpm]

Why was a macerator used? How difficult would it have been to install the soil pipe to the WC?

That is neither here nor there Jim, one way or the other the OP has suffered frustration enough.

 

[Leigh Florence]

Why was a macerator used? How difficult would it have been to install the soil pipe to the WC?

It couldn't be done because of Grade2 planning permission.

 

[rpm]

And what if a swept T wasn't used? So i think you are saying that a non return valve (one in basin, one in shower) is my best bet. Can the durgo valves be left in?

It would of been a swept T, yes non-return valve is the way I would go and place them almost anywhere you can.

 

[Leigh Florence]

That is neither here nor there Jim, one way or the other the OP has suffered frustration enough.

Also building control doesn't allow you to go through joists does it??

 

[Jim Goodenough]

No you certainly can't, you can obviously run alongside of them provided there's not too many other services in the way!