Soil pipe question 2, WC waste

[8ob]

I wouldn't be so quick to do away with a vent pipe in favour of an aav, its not all about air admittance. In a lot of cases there can be a back pressure and that can end up blowing air back through the traps etc if there is no proper vent in the system, happens a lot where sewers get overwhelmed through flooding or loaded up through over development.

Bob

 

[RaceDiagnostics]

I wouldn't be so quick to do away with a vent pipe in favour of an aav, its not all about air admittance. In a lot of cases there can be a back pressure and that can end up blowing air back through the traps etc if there is no proper vent in the system, happens a lot where sewers get overwhelmed through flooding or loaded up through over development.

Bob

I plan to keep the main vent pipe on the left of the pics.

 

[gaz1]

this is why you have air breathers to drains

 

[S-Rail]

I wouldn't be so quick to do away with a vent pipe in favour of an aav, its not all about air admittance. In a lot of cases there can be a back pressure and that can end up blowing air back through the traps etc if there is no proper vent in the system, happens a lot where sewers get overwhelmed through flooding or loaded up through over development.

Bob

Thats my understanding aswell , it’s to also help bent gas build up in the sewers , preventing dangerous explosions / build ups .

Was always told there should be one per X distance from mains , or per row of X dwellings .

 

[DickyDoDah]

Just been reading through these BS EN 12056-2: 2000 and think I will have system type 1.




If that is the case then I think I can have an unvented branch up to 4m long with the appropriately sized pipes.

4m was the length I was struggling to remember (old age is a B*$tard) You will have no problems if it is below 4m as far as the regulations go but the real life scenario may be a little different. A 110mm AAV is rather expensive and as you would only get issues on the smaller pipes on the sinksyou can get AAV's to fit these. I fitted them in my bathroom after the 100% correct, according to the regs installation glugged annoyingly. Fit these traps on your sinks and you won't regret it

McAlpine Anti-Syphon Bottle Trap White 32mm - Screwfix

Order online at Screwfix.com. Constructed from high temperature polypropylene with compression outlets. Suitable for use with basins and sinks. Neutralises negative syphonic pressure and eliminates gurgling. Multi-fit compression outlet suits waste pipes to BS EN 1451-1-2000. FREE next day...

www.screwfix.com

 

[Seadog]

I've fitted this style of trap everywhere. No longer any worry about syphoning.

 

[MoreWellie]

nope dont need it there as the water coming out of your tiolet wouldnt fill the 3-4" pipe anyway

and yet mysteriously it does, sucking the bath ubend dry in our case and letting smells into the bathroom. We just happen to have an almost identical installation

 

[gaz1]

and yet mysteriously it does, sucking the bath ubend dry in our case and letting smells into the bathroom. We just happen to have an almost identical installation

it shouldnt with an antivac bath trap

 

[RaceDiagnostics]

Well it is a non starter, I dug up the bottom of the stack on the left and found it went to a P gully trap shared with the rainwater downpipe.

Pics later.

 

[gaz1]

its still viable all depends on how you dig on the rainwater pipe

 

[Nick67GT]

this is why you have air breathers to drains

 

[RaceDiagnostics]

So this is what I found at the bottom of the vented stack, great, a 4 inch pipe? But going in the opposite direction to what I expected.

This is the back of the house, I imaging the main drain runs parallel to the back wall.

After a bit of water chasing I think this is what I have. Looks like the sink waste and both rain downpipes are mixed in the P-gulley drain.

Down the gulley trap, two input pipes and one exit. I imagine that the exit will head over to the main drain running parallel to the rear wall.

I will need to get Mrs RD to do a bit more digging......

 

[DickyDoDah]

That's quite a mess of drains you have there it might be easiest to dig the lot up and put a new chamber in the middle and lay new 110mm to the new toilet and a couple of gullies.

 

[gaz1]

thats more known as services drain

change of use would be dig the middle drain up and see whats there replace to a manhole drain system where you can have direct to main drain sole stack

as long as the left side and middle drain has a gully fitted to them you can change the third right gully to a toilet drain / down pipe gully

 

[RaceDiagnostics]

Thanks guys, more once I've got Mrs RD to do a bit more digging, I'll try to get her to do that while I'm doing the internal electrics and plumbing.

 

[RaceDiagnostics]

We she was out at it first thing this morning.

Dug out the bottom of the main stack at the house to see the direction it headed off in and then from the small drain back to the junction with the main pipe from the house. I think I will put the new manhole here (red circle) and take the new w/c waste pipe directly to there. I will drop an email to building control first to make sure they have no objection.

Very proud of herself.

 

[gaz1]

oh she lucky then, nice job shes done

she should think its lucky that its not backside in the air whilst digging it out though a nice view

you have a service surface drain thats filled from the other 2 drains against the house wall

you will have to dig that service drain out and replace it with

320mm Chamber Base (£12.39) 2 x 110mm Side Inlets & 2 Blanking Plugs

320mm Chamber Base With 2 x 45° 110mm Side Inlets

skyplastics.co.uk

that joins into the other 2 pipes which you will convert to plastic and lower them so they join as one

you will need to change all 3 of them to gulley traps

Universal Roddable Gully

This 110 mm round universal roddable gully is particularly useful if you're adding a waste outlet to a combined system that has foul, rainwater and domestic 'grey' water discharging to the same drains. The grid on top keeps leaves and other rubbish out of the system, while the shape of the gully...

www.toolstation.com

and also fitting a tee for the soil pipe as well

that would mean creating a new hole again to the left side fitting a tee and then renewing the soil pipe and a new pipe for your gully

tee right side and fit gully for rainwater

left and midlle wants new gullys fitted

round circle your removing the drain replacing with manhole

 

[RaceDiagnostics]

That seems like a lot of work for my Mrs, can't she just leave the service drain in place and put the manhole here with a three way entry, the two existing pipes and a new one from the new WC?

 

[sako243]

Seems we're both on a voyage of discovery except mine involved a 5t digger, dumper truck, JCB and £600 of pipework just to sort the rainwater.

 

[gaz1]

I love it when customers say it wont cost much wont take long to do

then its how much it cant be that dear not for that little bit of pipe work to the drain for a new toilet to be fitted