Urgent Help Required - Mains Drains layout on new build

[anuraj]

Hi All,

I urgently need some advice on main drains layout.
My property was an old bungalow without main drains.
Now we are looking to start a new self-build I want to ensure I am on the right page with the layout of the new waste system.

Below is a image of the layout I am thinking of.
The main connection is at the foot of the driveway and is 1400mm below the ground level.

View media item 44642
Please can someone advise if I am on the right page with this design or if it can be improved...

Help Much appreciated!

EDIT

The dotted line points in the direction of my outbuildings - I may want a connection from them one day...

 

[freddiemercurystwin]

Why not get rid of IC-B & C and run all 3 soil pipes into IC-A, maybe moving it the left a little?

 

[garyo]

Why the urgency?

 

[anuraj]

I have reworked the drawing as per your recommendation and here is what I got.

View media item 44651
I have two main worries:

- The lengths of the main run
- is the main run @110mm sufficient to cope with the flow?

max setup for the house will be:
- 8 toilets
- 10 basins
- kitchen outlet
- washing machine

With this setup, the new drainage will need to cross under the footings at 3 points.

Any thoughts?

 

[anuraj]

Why the urgency?

I want to start the footings, next week. The whole ground floor is suspended block and beam, raised 1m off the ground.

My groundworks guys have let me down, so I have to solve this before the rest of the schedule starts to back up.

looking to get all the pipes under the building in whilst I can use the digger onsite and before the block and beam floor - will connect up and commission the system later.

 

[freddiemercurystwin]

I was suggesting you ran all 3 pipes into 1 chamber rather than have 2 of them join the single run under the house.

Why so many toilets and basins?

 

[^woody^]

I would suspect that inaccessible connections beneath a building would not be acceptable

 

[mikric]

Get rid of the connections under the floor
why would you want to take an external SVP back in under the floor
A 12m run is the max between ICs, get the drains outside of the building as soon as possible.

 

[fmck]

If you can acheive no connections under your floor you will most likely be the first building to do this and would recommend you patent your idea

If time is the main issue just make sure all your pop ups are in and clearing the building. MOST IMPORTANT IT PASSES A PRESSURE TEST
You need that test to pass after any incasing in concrete.
Witness it yourself but BC will eventually want to see it pass.
Get your builder to release one of the bungs at the far end of the line while you witness the guage drop to ensure he hasnt cheated once the test has held to satisfaction.
Everyone will cheat if its not holding its easy to do and save a lot of hard work to put everything right.

At the end of the day if your pop ups are clear of the building it easy enough to direct them from there.

 

[Norcon]

If you can acheive no connections under your floor you will most likely be the first building to do this

Where do you get that from? I know hundreds of buildings with no drain connections under the floor. Hardly something new.

 

[theoldun]

With respect both your drawings are a waste of space. It is an easy house to drain. Answer a few questions and will tell you how.
Is it going to be bungalow or house?
Is it block and beam floor?
My eyes are not so young now, so IC- B, does that read invert level is 775mm below ground level?
IC- A, does that read invert level is 1050 below ground level?
IC- B does that read 675mm below ground level?
Why is the bottom soil stack external?
What is datum of dpc in relation to IC- B ground level?
In answer to your other questions, we take up to 10 units on a 110mm pipe, each unit consisting of WC, bath, wash basin, sink and washing machine running at a flow rate of 4.1 litres second all as H1 table 5 BRs. We change our flow rates around on our falls though to avoid a bottle neck at the discharge point into main sewer.
Regards oldun

A 12m run is the max between ICs, get the drains outside of the building as soon as possible.

We have always been under the impression that between IC and IC it is 22m
Regards oldun

 

[fmck]

If you can acheive no connections under your floor you will most likely be the first building to do this

Where do you get that from? I know hundreds of buildings with no drain connections under the floor. Hardly something new.

Point was if your pipes are below floor you have to have a connection unless there is some new fangled flex 4" that does it.

No one these days wants plumbing coming out of exposed walls outside didnt even consider that one on a new build. Would you?

 

[mikric]

[quote="theoldun"
We have always been under the impression that between IC and IC it is 22m
Regards oldun [/quote]

Have you ever seen anyone trying to use 20m of drain rods In my opinion I would say that 12m is more practical, the regs have not been updated for years and there is loads of stuff that drains are "expected" to deal with nowadays, wetwipes, sanitary towels etc.
If I were doing a new build for myself no way would I go for 22m but if you are happy to go 22m between ICs then go for it

 

[Hugh Jaleak]

Try rodding a 91m run with 'Steel Kane' rods..... (Some muppet had built a conservatory over their manhole, then claimed they didnt have one.... Only house in the street that didnt then?)

22m isn't a massive run, and with the jetting gear most contractors carry these days, shouldnt be too difficult to deal with.

 

[anuraj]

Many thanks to everyone for the responses.
My apologies for the late reply - I have been away for easter.

Here goes, answering the questions:

With respect both your drawings are a waste of space. It is an easy house to drain. Answer a few questions and will tell you how.
Is it going to be bungalow or house?
Is it block and beam floor?

This is to be a house. The image shows the new proposed footprint.
The floor is block and beam. The DPC level is 1m off the ground, meaning the void under the block and beam floor is around 800mm.
This is a flood regulation in our area.

My eyes are not so young now, so IC- B, does that read invert level is 775mm below ground level?
IC- A, does that read invert level is 1050 below ground level?
IC- B does that read 675mm below ground level?

My apologies as the terms I used are maybe not 100% accurate.
The levels are indeed the depth from the ground level to the bottom of the trench - following a fall of 1:40

IC-A - 1050mm below ground level
IC-B - 775mm below ground level
IC-C - 675mm below ground level

I have no idea if this is the correct layout or if so many IC's are even needed.
The starting point is, the main drains connection at the foot of the drive way is 1400mm below ground level

Why is the bottom soil stack external?
What is datum of dpc in relation to IC- B ground level?

They stack is external as I don't want it running up in the front living room + thought it would give an external access point if needed.
The DPC is 1000mm above the ground level of IC-B.

Any design / help with layout from anyone would be much appreciated!!