Laying New Drain - questions.

[a546345]

We would like to convert part of our conservatory into a utility room, which means digging a new drain. The drain will need to take waste from a sink, and washing machine, but no toilet/shower.

Plan so far is to dig a trench as per the diagram below, to an existing manhole. Piccie of manhole attached.

Fall will be 1:40
Plan to then fill trench as follows

1. 100 mm of pea gravel < 15mm
2. 110mm plastic soil pipe
3. 100 mm of pea gravel from top of pipe
4. backfill


My questions are

1. Do I need to provide rodding access at each change in direction (green boxes). If so, do I get a bend with an access port like this? http://www.wickes.co.uk/Wickes-110mm-87-5-Deg-Access-Bend/p/133866. How do I get access to the access port from the surface?

2. The washing machine will probably connect to a combined trap on the sink, so there will only be 1 40mm waste pipe going into this new drain. How do I bring the 110mm up above ground (red box) and connect the 40mm pipe to it?

3. How best to do the additional connection into the manhole. The pipe will come from the left. Can the pipe enter the chamber just above the benching on the left hand side?

I haven't yet spoken to Building Control, but I will do on Monday.

 

[mfarrow]

Why are you doing such a convoluted route instead of just straight down the extension and out the front?

The changes of direction will need ridding access via a mini chamber.

For the existing manhole you'll need to look at this and remember you've a foul manhole: http://www.pavingexpert.com/drain05.htm . Is that a dead leg at the top of the picture?

 

[a546345]

Hi Mfarrow. The direct route would be through the existing kitchen, so more disruption.

The top feed into the manhole is from the Kitchen - sink, dishwasher, washing machine.

The right hand side feed into the manhole is from 2 bathrooms - showers, sinks, toilets.

So at each change in direction, I need one of these? http://www.screwfix.com/p/floplast-d810-45-inlet-inspection-chamber-base-black/68090

The inlet is at 45 deg, not 90 deg to the outlet, so I'd also need to put a 45 deg bend on the pipe just before it enters the chamber?

 

[PullerGas]

If there's a huge difference in the invert levels of the new & existing drains? You could always fit a 'drop shaft' or drop manhole as we'd call it, on the existing manhole. The straight route would be 100 times better as stated.
HTH

 

[mfarrow]

Yes that chamber will do. Do a search for ramped rodding points so you don't dig the full depth all the way. Two examples:
View media item 63966View media item 23647View media item 45133View media item 20829
Read the Approved Document for building regulations on Drainage and Waste Disposal (Part H).

 

[a546345]

Thanks for the replies, Trench is now dug, and Building Control have been and said ok so far. They're coming back tomorrow evening to see it finished. We have run the internal waste in 40mm not 110mm, and that now pokes out of the wall underneath finished ground level.

I am not sure what type of gully/hopper to get that will allow the 40mm pipe to flow into the 110mm connection underneath ground level - could anyone post a link to an example please? The BC chap said surface water shouldn't drain into the sewer, but I can only see hoppers and gullies with a grid on top.

 

[mfarrow]

I believe one of these and Hunters gullets will do the trick. You may wish to call they're tech team to confirm.

http://shop.parkerbs.com/hunter-underground-110mm-sealed-access-plate-black-ds47-10076-p.asp

 

[poletim]

We would like to convert part of our conservatory into a utility room, which means digging a new drain. The drain will need to take waste from a sink, and washing machine, but no toilet/shower.

Plan so far is to dig a trench as per the diagram below, to an existing manhole. Piccie of manhole attached.

View attachment 82043


Fall will be 1:40
Plan to then fill trench as follows

1. 100 mm of pea gravel < 15mm
2. 110mm plastic soil pipe
3. 100 mm of pea gravel from top of pipe
4. backfill


My questions are

1. Do I need to provide rodding access at each change in direction (green boxes). If so, do I get a bend with an access port like this? http://www.wickes.co.uk/Wickes-110mm-87-5-Deg-Access-Bend/p/133866. How do I get access to the access port from the surface?

2. The washing machine will probably connect to a combined trap on the sink, so there will only be 1 40mm waste pipe going into this new drain. How do I bring the 110mm up above ground (red box) and connect the 40mm pipe to it?

3. How best to do the additional connection into the manhole. The pipe will come from the left. Can the pipe enter the chamber just above the benching on the left hand side?

I haven't yet spoken to Building Control, but I will do on Monday.

View attachment 82044

hi there,


How did it end in end? Did the builing control allow for the internal dropshaft in the end?

Looking forward to hearing from you.

 

[Nige F]

Don't hold your breath in the end it's an ancient thread .

 

[a546345]

Hi, yes BC were happy with what I described in the original post. All been working well for the last 8 years! They seemed fairly pragmatic.

 

[Hugh Jaleak]

How did it end in end? Did the builing control allow for the internal dropshaft in the end?

Speak to your Building Control before getting too carried away. They all have their own ideas and interpretation of what is acceptable to them and what isn't, I have known two out the same office to want different specs on the same job.