Vent or no vent for additional bathroom

[Doomageta]

Hi there,


Looking to get more advice as a couple of plumbers I called I told e different things and i want o get it right.
I am adding a ensuite to a room and was planning to get it connected to the existing main drain running along the back of the house (where existing bathroom and cast-iron soil vent pipe nearby are installed) and then down the side. Looking to Tee off from the existing pipe to new ensuite (in red on the attached picture if it shows).

One plumber said i need to turn the pipe that comes from the gutter into a 4" vented stack pipe that all the waste from the ensuite will connect to a well as the rain water.
Another said that they could just tee into the drain without needing anything else done since it is so close to the main drain pipe that we will tee into.

What is right in this case?
Thanks

 

[BLOD]

If you want to do it right get some proper plans drawn up and get them approved by your local building control office.
If you're putting a new soil stack in they will probably want to see it pass an air test anyway.

 

[oz-plumber]

Avoid all that stuff...just install a macerator.
40mm PVC outlet to drain.

 

[gasmanrob]

I would check with the local water authority before using the rainwater as a soil, in some area rain water is a separate drain system, as long as it possible to achieve the correct fall from the soil then I wouldn't see a problem teeing off of the existing although if it is cast I would replace the stack for PVC, as cutting in with plastic just for a tee could result in the weight of all the cast above it resting on that joint! In the grand scheme of things it's not a massive extra cost....

 

[gasmanrob]

Sorry just looked at the picture obviously you wouldn't be teeing off of the verticle stack but from the underground...

dig it up chamber in and new soil stack.....

wouldn't recommend using a macerate unless there is no other alternative they are noisy and prone to failure, no one enjoys macerators especially at 2 in the morning when you get up to use the loo and as a result everyone is up!

 

[Doomageta]

Thanks for the answers so far.
BLOD i have been in touch twice with the council building reg/inspections department who told me twice that i do not need a building warrant or anything else. (They did say that i would need one if i wanted to add a window). I am up in Scotland if it makes any difference. Sorry about the hand sketch if it is not readable.

Gasmanrob, it is exactly as you said in your last post (no macerator). I am attaching another picture since it is already dug up. The 4" pipe carrying dirty water (from WC+basin+shower) will come out of the wall on the left besides the rain water vertical pipe and T into the yellow/orange soil pipe (about 1m distance with WC directly on the other side of the left wall), which runs down towards the front of the house then street. What i am not sure about is if i need an additional vertical vented pipe to be connected to that as well.
Any advice??

There are already two vented vertical pipes at the back of the house where the existing bathroom and kitchen are located.

Thanks

 

[Doomageta]

Thanks for the answers so far.
BLOD i have been in touch twice with the council building reg/inspections department who told me twice that i do not need a building warrant or anything else. (They did they i would need one if i wanted to add a window). I am up in Scotland if it makes any difference and it is a bungalow. Sorry about the hand sketch if it is not readable.

Gasmanrob, it is exactly as you said in your last post (no macerator). I am attaching a couple of pictures since it is already dug up. The 4" pipe carrying dirty water (from WC+basin+shower) will come out of the wall on the left besides the rain water vertical pipe and T into the yellow/orange soil pipe (about 1m distance with WC directly on the other side of the wall), which runs down towards the front of the house then street. What i am not sure about is if i need an additional vertical vented pipe to connect to that as well.
Any advice???

There are already 2 vertical vented pipes at the back of the house besides where the current bathroom and kitchen are located.
Thanks

 

[rpm]

Bit harsh regarding "noise levels and prone to failure" Rob, mainly comes down to how much you pay and how you use it but agree only install one when you have no other alterative.

 

[oz-plumber]

I wouldn't use a macerator either!!!.

When I suggested this, this post was unanswered for 2 days and his previous post was not answered at all.

Obviously not a plumber and the suggestion was a wind - up.

No harm intended.

I can't believe that people write into this forum regarding fairly major Plumbing works and expect Plumbers to give them advice on how to do the work.

What's probably more unbelievable is that quite often they get the advice they are asking for.

This thread for example!!!

 

[Doomageta]

oz-plumber, I am not doing this "major work" myself but (as stated in my initial post) one plumber i called in for a quote told me that i needed a vent and another one said i did not. Hence i was trying to see which way to go using this forum.

More generally, I do not see an issue with passing on knowledge/experience if someone else asks but, obviously that is my personal opinion and you will have yours. I like to know what people are talking about before making a decision.

Anyway I suppose I could go and ask on a diy forum if I am offending the professionals

 

[rpm]

Stick around doom and I`m sure you get will helpful suggestions from us but not from me because I`m a pump man not a plumber.
Can`t recall oz blowing a fuse before so perhaps it was just a bad day which happens to the best of us.

 

[Alex Pelton]

it depends on the height difference between the wc and the sewer. cant remember what it is. 1.3m ringing a bell though. i'd fit a stub stack with a durgo or a full stack personally, no chance of induced siphonage then

 

[oz-plumber]

Dooma,

How did you go with your shower tray installation.?

In that post you state you are quite handy at DIY and it seems that you did all the Plumbing work there yourself.
I just assumed that this would be the same situation.

You did say you had 2 plumbers around and they both had differing opinions.
That's not unusual. Were their prices the same?

Why not get 3 or 5 and take the opinion of the majority - even numbers may leave you with a stalemate situation.

Your job seems not to be a difficult at all.
It involves cutting a branch into and existing sewer and running wastes for a bathroom.
Plumbing 101 in my book. ( it can't get any simpler )

Good luck with it.

 

[Doomageta]

Alex, thanks for the advice (2 vs 1 for full vent). Space is limited inside so, a durgo or other internal aav is not really possible.

The height difference between floor level inside the house and the main soil pipe buried outside is about 1m.

Oz-plumber, thanks for the suggestion. Plumber number 3 is coming around at the weekend so, hopefully i'll get a more definite answer.
The job probably is not the most complex to actually do but, i was not sure of the regs hence I thought that calling a plumber in for that part would be safer. Better to get it done right the first time around if you are on a budget (also i need extra copper pipes connected to CH for towel rail and they do that too). It is cheaper that getting it fixed later on.
The plumber who initially quoted with the full stack was more expensive. However i phoned the "no vent" plumber today and he said he would charge about an extra £90 (parts+labour+vat) to put a vented stack in. He still maintained that he doesn't believe i need one since the connection is so close to the main soil pipe run.

The shower tray is not down yet (thanks for asking). Just started work again after saving up for a while. Walls are tanked, shower bar is mounted. I will cover the whole floor area with a sheet of wbf ply and install the resin tray after drilling a hole for waste (running under floor). Still not decided between silicon bedding or cement mix. I would prefer cement but i don't want to raise the level of the tray too much. Then the rest of the floor will get tiled over.

All comments are much appreciated...will post final result if the phone pictures behave.

 

[Doomageta]

Job done a couple of weeks ago WITH a new vent stack. It looks like i also have a rain gutter downpipe to change too.
Thanks everyone!!!