New soil stack layout question....

[Adam182]

Hi Everyone,

Just trying to plan out for my new soil stack

which will include the Toilet/Basin/Bath wastes.​

These are my two ideas, I am just looking for any feedback as to which I should opt for (or neither).

​

Thankyou any feedback is much appreciated.

 

[Hugh Jaleak]

Top pic is better option. If the basin waste is over 3m long, you'll need to up it to 40mm for the rest of the run. Long radius bend needed at the foot of the stack if you weren't aware.

 

[muggles]

It's max 1.7m for 32mm, max 3m for 40mm

Personally I'd do it as per the second picture, but I'd do away with the 45 near the wall penetration for the toilet and just have the 90 going through the wall.

@Adam182 this work is notifiable to Building Control so you should check what they'll be happy with before you start. You should aim for a fall of 44mm per metre on all waste & soil pipework

 

[Adam182]

Top pic is better option. If the basin waste is over 3m long, you'll need to up it to 40mm for the rest of the run. Long radius bend needed at the foot of the stack if you weren't aware.

Hmm yeah doing it this way means the basin will be over 3m now you mention it, I could just run 40mm right through I suppose. Thanks for the heads up about the long radius

It's max 1.7m for 32mm, max 3m for 40mm

Personally I'd do it as per the second picture, but I'd do away with the 45 near the wall penetration for the toilet and just have the 90 going through the wall.

@Adam182 this work is notifiable to Building Control so you should check what they'll be happy with before you start. You should aim for a fall of 44mm per metre on all waste & soil pipework

The only problem with doing away with the 45 would mean I wouldn't have enough room above the pipe to boss into it. The 45 was my way of getting the pipe a bit lower leaving room to boss into.

Thanks for the feedback everyone.

 

[Adam182]

For closure I just want to post up photos of what I opted for in the end.

Went for 40mm for both basin and bath/shower bossed into the main soil run from the toilet.

Thanks again to everyone for their input, its much appreciated.

 

[Hugh Jaleak]

I do trust you are going to finish it?

I dont know what you're planning with the rainwater, but I wouldn't connect it to the stack. Downpipe will act as a vent and you risk filling your loft space with drain odours....

 

[Adam182]

I do trust you are going to finish it?

I dont know what you're planning with the rainwater, but I wouldn't connect it to the stack. Downpipe will act as a vent and you risk filling your loft space with drain odours....

Haha yes I plan on finishing it, I'm swapping the waste and rainwater around so the waste will vent where the old rainwater used to be (with new pipe) and a new rainwater will be added around the corner with all the old stuff removed.

The current situation is just temporary for now.

I do have a question though, do I HAVE to use a rest bend at the bottom of the soil stack? I might get it but it will be tight fitting one into the current drain as it is so shallow, I fear it might leave some of the brown rest bend poking out of the ground.

 

[Hot&Cold]

do I HAVE to use a rest bend at the bottom of the soil stack?

The new drilled outlets are very neat
Rest bend,it depends on a lot of if's & butt's but usually the answer is yes a standard rest bend. Where is the current underground drain remembering your photos only shows the rear of property.
Also remember the back door is accessed via a raised surface,we cant see what is directly under the proposed soil route but if the top of a rest bend was same height as the raised floor level (approx 4 brick courses) it should work.

some bco attention is required but this is a diy forum,who the feck cares.

Happy plumbing

 

[Hugh Jaleak]

Rest bend is needed to allow a smooth transition of the falling soil, round into the sewer. The 'Supersleve' clay bends are somewhat shorter than the plastic equivalents for some reason, if you really didn't want to use plastic, but personally, I'd use a plastic rest bend, and paint anything above ground level to protect it from sunlight. Some Plastics manufacturers actually recommend painting their products to provide protection against the UV from the sun.

 

[Adam182]

Photo for closure, I managed to just about fit a restbend in, I believe the finished driveway will cover it (when I get around to it) hope it looks ok!

 

[Nige F]

Photo for closure, I managed to just about fit a restbend in,

Looking @ that reminds me when , as a young plumb I'd have 8 pints and some "blow" on a Friday night. Then on Sat. morning go to one of my Private Jobs

 

[Hot&Cold]

Adam182,the fish eye photo distorts the image ,looking to see if the new drain angle is suitable .

Previously have done same work and the bco were very interested in chamber depths,chamber cover seal,drain benching (in my area,they only accepted Granolithic mortar) done to a very smooth finish,correct oblique angle and a few more including knowing the fall on the existing buried drain pipe.

Maybe its time to check with your project bco .

 

[Hugh Jaleak]

Keep an eye on that, with the bend so close to the chamber, you may get some 'spatter' of soil discharge on the benching opposite, which can build up to the point it blocks the drain, although given the size of the chamber and the available room, it is probably difficult to do much else.

 

[Nige F]

Back in the day a well known supplier of underground and above ground plastic pipe, had a similar problem with their formed bases that were then bricked up from to make a conventional manhole. Just as HJ said. They made some shields out of thick plastic, and fitted them to the manhole walls so the solids struck, then slid down. All done F.O.C on a Social housing ( new build ) site I was maintaining at the time. It was the only practicable answer, so fair play to them.

 

[Hugh Jaleak]

I recall (probably the same manufacturer), making blanking sections for unused inlets on their 450mm chamber bases, ok if you didn't require a connection on both sides! Have seen a case where stack and chamber were immediately adjacent in order to fit them into the return at the side of the property, right outside the kitchen door. Got called to investigate a smell, lifted the cover to find the chamber half full after the lump of dried out waste that had accumulated on the opposite side, had slid into the channel and blocked the outlet. Used to be a regular job to visit and hose chamber out after that.