I think this pipework should be simpler, but I can't see how yet.

[dnb]

This is the current layout of the soil pipe I am installing later next week. I can't help thinking that it can be simplified. Simple is good according to part H after all.

All the soil stacks have rest bends at the bottom (I believe this is a rule - please correct me if I'm wrong) and I can't have pipes joining where they would be inaccessible. So that's nowhere under the house. The larger circles on the diagram denote inspection chambers. All internal soil stacks will have an AAV on the top (so that I don't get thermal bridges) and the system will be vented with an external vent pipe on the north wall. It's out of the way there and nobody will really see it. It would be really nice to get the area supporting ensuite 2 and the downstairs WC to be simpler.

 

Before anyone says it, I know I've made a rod for my own back by not collecting the bathrooms together in the house for plumbing installation efficiency. I decided that I will hopefully live in the house for rather longer than it takes to design and build it. But I may of course be very wrong here!!

 

I would love to hear if there's such a thing as a rest tee piece, but I think I'm out of luck on this one.

Thanks for any insights.

[Dreadnaught]

Oh I am an amateur, but I would think you can greatly simplify that. Here's a first idea. With a bit more thought, and close reading of the Part H constraints, I think you could simplify it further. I got mine down from 8 ICs, as originally proposed by my drains engineer, to 2x 450mm ones and 1x 300mm one.

 

 

Obviously, check the above against Part H, especially for the distances allowed between ICs and whether it is permitted to have two soil stacks on a single drain as I have tentatively suggested. And for falls.

 

 

Edited March 7, 2020 by Dreadnaught

[JFDIY]

Move the main chamber where the branches collect to the right and use long radius , roddable 45 degree bends and you can loose the chamber(s) at the corner of the property as well. Bends are cheaper than chambers as well?

 

 

[dnb]

6 hours ago, JFDIY said:

Move the main chamber where the branches collect to the right...

 

That's a good idea if it fits. I have a bit of a constraint there in that the treatment plant is getting close to the RPA of a tree I want to keep. I like cheaper too!

 

8 hours ago, Dreadnaught said:

permitted to have two soil stacks on a single drain

 

That is something I thought was on the "don't do this" list, along with a strong preference for drains to take the shortest route to get out from under a property.  Very happy to be wrong of course!

 

8 hours ago, Dreadnaught said:

...from 8 ICs, as originally proposed by my drains engineer...

 

This is why I'm here - this place has saved me from lots of trouble so far. The original scheme drawn above is from my architect and it certainly complies with part H, but I suspect costs can be cut. Especially when you see the scary prices in the Osma catalogue (that I assume nobody actually pays)

[JFDIY]

2 hours ago, dnb said:

scary prices in the Osma catalogue

Go into Travis Perkins and ask for their best price, I usually only pay around 40% of list price.

 

Also check out JTM plumbing, I've had loads from there.

 

Oh and you could use two 30degree bends and a short straight section and it would still be rod-able, or a swept 45 and a 15 or 30 at either endetc.  Also you can get long radius 90 that is rod-able, you may have to install it than prove to your building control that rods will pass without obstruction rather than expecting them to accept it from plan, a practical approach might yield a more favourable result.

Edited March 7, 2020 by JFDIY
Extra info added

[dnb]

3 hours ago, JFDIY said:

Go into Travis Perkins and ask for their best price, I usually only pay around 40% of list price.

I have spoken to my local Jewson (no TPs locally now) and they've suggested a sizable discount on list, similar to your experience.

 

A bit of thought later and I have got to this:

It removes 2 inspection chambers but doesn't really simplify much.

The pairs of 45 degree bends as drawn could easily be a mixture of fittings or a long 90 degree bend (because one bend is probably going to be cheaper than two) - I'm just being lazy with the drawing.

ADH suggests 22 metres between inspection chambers is OK. My longest run is 17 metres, so happy days.

I can't resolve the rodding access to ensuite 2 and the downstairs WC any other way than I've drawn. There isn't the height above the ring beam to do what @Dreadnaughtsuggests. I had hoped I could make more use of access points inside the house, but this proved difficult because parts of it would be right in the way. It's probably a good idea to have that long run easily accessible from both ends so it's probably serving a useful double purpose.

 

 

If the external vent could go on another wall I could do quite a bit but I'm not allowed to do this by Order (for those of us who remember old Pratchett books and encourage our children to read them ) Order often forbids or commands things to happen round here.

 

Edited March 7, 2020 by dnb

[Temp]

All I would do is move the final IC to the left and use the 46 degree connections on it to eliminate the 45 degree bends you have in the pipe runs.

 

I might also put IC where you have 90 degree bends on the final runs.

Edited March 7, 2020 by Temp

[Russell griffiths]

Just to add my bit. 

my pipe runs have lots of  ic I could remove half of them and use long sweeping bends 

WHY? I want to access every pipe directly inline with its final point

why would I want to increase the rodding length from 7m to 14m 

i want a house that functions well and is easy to work on. 

If you are having a very posh drive and don’t want to see an ic then I can understand why you would want to reduce the number, but if you can hide them in garden areas I see no reason to reduce the number. 

 

 

 

[dnb]

4 hours ago, Russell griffiths said:

Just to add my bit. 

It's all much appreciated. It's always been really useful to discuss things here.

 

At the end of it all, simple (so it functions properly) and easy to work on (so it's not like doing wheel bearings on a Jaguar) are the goals. Fewer pipe runs seems a better solution - more water flowing through fewer pipes ought to keep them cleaner by my crackpot thoughts. I think I will add back in the inspection chamber at the bottom right based on the above comments. It gives a bit of scope for a change in fall too. I seem to have won the discussion with Order for the moment, so the second, simpler drain picture looks like it is possible. It's actually good to get the north (top) of the house clear because there are a number of services congesting that side.

 

I don't really want too many ICs in the lawn to the south (bottom in my pictures) of the house, so yes there is a little bit of me worrying about asthetics here. Come to think of it, I don't think I've posted anything in my blog about what the house will look like! I ought to fix this.