Which foul drain runs is better, red or blue?

[Dreadnaught]

Hi guys, which of these two foul drain run designs is better, 1 (red) or 2 (blue) and why?

 

 

Edited November 2, 2019 by Dreadnaught

[scottishjohn]

blue-

good straight runs between the inspection chambers

there is a maximum distance you should have between rodingpoints /inspection chambers --look it up

 why not a rodding point/chamber  where it the bend is ?

Edited November 2, 2019 by scottishjohn

[Dreadnaught]

Thanks @scottishjohn.

 

10 minutes ago, scottishjohn said:

there is a maximum distance you should have between rodingpoints /inspection chambers --look it up

 

 

Yes I believe it is 22m according to Part H.

 

10 minutes ago, scottishjohn said:

why not a rodding point where it does the bend?

 

I think it is because rodding points are only for pipe terminations. An IC is needed for a corner > 30º.

 

Any other votes?

Edited November 2, 2019 by Dreadnaught

[scottishjohn]

1 minute ago, Dreadnaught said:

 

I think it is because rodding points are only for pipe terminations. An IC is needed for a corner > 30º

 IC then 

[PeterW]

Neither...!!

Far too complicated and you’re creating problems for yourself .... 

 

Try this - single IC and the utility to kitchen creates a decent wash through

 

 

[Dreadnaught]

Thanks @PeterW. I like your simple approach but the council tree officer might not approve it because of the root-protection zone for the chestnut tree on the south boundary, shown with a green dotted line.

 

 

[PeterW]

Done carefully that is fine ..!!!

 

The only difference when you’re working in the RPA is that you may need to do more work by hand - I’ve had to do this - basically went within 800mm of the trunk of a sycamore but had to do all excavation manually. 
 

Just put a note that says “x to y will be hand trenched where required to avoid tree roots.”

 

At that distance out a HC will be no more than 60-70mm thick and will be deeper than your trench ..!

[Oz07]

Out of the 2 i'd prefer red. Any problems only effect one run not the whole system. May be that it just works better in my head.

[Dreadnaught]

@PeterW, in your scheme, how would one rod a blockage between the utility room and kitchen?

[PeterW]

A blockage of what ..??!! 
 

Only thing in a utility should be a sink and a washing machine ..?? A 40mm waste into a 110mm swept elbow there is nothing really that can block ..? You’re not putting food or fat down it, and there is nothing such as wipes or other rubbish in the run ..??
 

Same with the kitchen - swept up into the floor with a socket in the top, utility tees in at 90 degrees just after the elbow and you’ll have basically 65c water flowing through that whenever your dishwasher or washing machine clears out. 
 

Washing machines are great at cleaning out drain runs - a 90c maintenance wash with a bio powder once a month will not only keep the machine clean, it will also sort the drains too ... 

[Mr Punter]

Red but scrap the kitchen IC. Use the bathroom near to utils in the main run inlet, with a bend just before the IC.  Use the 2 inlets on the left of the IC for utils and kitchen, the R/H 45 inlet for the other bathroom and blank off the final inlet.

[Oz07]

@PeterW I agree with your sentiments but have always wondered how come of laying drains at 1:80 they say a toilet should be connected as a minimum with 110mm pipe? That's the way I've read it but as you say, surely kitchen and utility runs are not as likely to block?

[PeterW]

17 minutes ago, Oz07 said:

@PeterW I agree with your sentiments but have always wondered how come of laying drains at 1:80 they say a toilet should be connected as a minimum with 110mm pipe? That's the way I've read it but as you say, surely kitchen and utility runs are not as likely to block?

think we are at cross purposes here ..! All the underground should be 110mm, only when you do the utility and kitchen is it reduced to 40mm above the slab. Toilets are always 110mm

[Bitpipe]

Agree with @peterw  - also consider that ICs are a reasonable cost, as are extension collars and nice Clarke drain covers (the type you can inlay with whatever you're using in your patio). Plus the labour to place them etc.

[Dreadnaught]

Yes, thank you @Bitpipe.

 

My engineer initially specified four ICs for the foul drains and yet another four ICs for the rainwater drains, eight in total.

 

With the advice from BuildHubers, I hope now to get that down to just two ICs for each, four in total, saving quite a lot of money and effort.

[Oz07]

47 minutes ago, PeterW said:

think we are at cross purposes here ..! All the underground should be 110mm, only when you do the utility and kitchen is it reduced to 40mm above the slab. Toilets are always 110mm

No you miss my point. Doc h implies that 1:40 is minimum gradient unless you have at least one w/c on the run then 1:80 permissible. Always puzzled me

[PeterW]

Think it’s to do with flow rate tbh ..!

[mvincentd]

[Bitpipe]

2 hours ago, Dreadnaught said:

Yes, thank you @Bitpipe.

 

My engineer initially specified four ICs for the foul drains and yet another four ICs for the rainwater drains, eight in total.

 

With the advice from BuildHubers, I hope now to get that down to just two ICs for each, four in total, saving quite a lot of money and effort.

Same happened to me, I have loads also but wasn’t savvy enough to consolidate them and quite a few are in tricky spots, became very obvious when laying the paving at the end of the project.  Poor landscaper had to do his best to fit paths etc around them.

[Dreadnaught]

Thanks everyone! Superbly helpful. Here's the new plan based on all your comments. Got it down to just 3x ICs (from 8x in the plan by the engineer). What does everyone think?

1. Is it OK to have the ICs just outside my gate? Nobody owns the road. Would help to keep the IC's off my paving. The road is concrete. 
2. The gutters (shown as red dotted) are long, about 15m each. Is that OK with a single downpipe serving both gutters. I tried a few online calculators and think it is but not sure. Roof is 142 m². 
3. The foul run is 12m to the IC and then about 12m to the bathroom, so the max allowable.
4. The rainwater run is about 24m, which seems OK as Part H says 45m max from rodding eye to IC (!).
5. In the road, the storm main drain is alarmingly deep, 2.2m. The foul main drain is just 1.2m deep. Think I will need a trench box.

Then I just have to convince the engineer to change his design and tree people to let me (hand-) dig nearer the chestnut tree.

 

D.

 

(IC = inspection chamber. Part H = building regs.)

 

 

 

 

[Mr Punter]

I think it would be better to have the final ICs on your own land.

 

Gutter outlet will be OK if all properly sized.

 

Run all the drainage fairly shallow and just dive down where you are connecting into the main drain.

[scottishjohn]

2 minutes ago, Mr Punter said:

I think it would be better to have the final ICs on your own land.

 

Gutter outlet will be OK if all properly sized.

 

Run all the drainage fairly shallow and just dive down where you are connecting into the main drain.

If on the public road then you should be using cast iron "heavy duty things - a 40 t load  cast iron manhole frame and cover --very exspensive 

 cheap galvanised one will not be fit for purpose  in public road -

https://www.draindepot.co.uk/600mm-x-450mm-d400-40-tonne-ductile-iron-cover-frame.html

[Dreadnaught]

27 minutes ago, scottishjohn said:

If on the public road then you should be using cast iron "heavy duty things

 

Good point. It is not an adopted road, indeed it not owned by anyone, but it it is open to the public, although I shall be the only regular car driver across it as just beyond my entrance there is gate blocking the road which I have never seen opened.

[scottishjohn]

1 minute ago, Dreadnaught said:

 

Good point. It is not an adopted road, indeed it not owned by anyone, but it it is open to the public, although I shall be the only regular car driver across it as just beyond my entrance there is gate blocking the road which I have never seen opened.

If there are other users --maybe they will have a delivery on a big artic -- which could damage a lesser cover