new extension plumbing

[ragsta]

Hi, after doing alot of work myself i'm next going to try and tackle the plumbing - only water. The following is what i planned. Does it look ok ? i've got 2 routes in the concrete floor pre made and one is pictured.
I'm concerned at point 1 in the picture of any contaminated water working into the drinking supply. Is there a reverse flow stop valve(think i've seen one) i can use there/ or must use ? i'm going to use 15mm copper pipes. We may also keep the washing machine where it is or move it near to the dishwasher. Ill be covering the copper in that cloth lagging (yet to find) may not need to fill the channel after. Thanks for all help. ragsta

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• ragsta
• 23 Feb 2012
• 1

 

[seco services]

I'm concerned at point 1 in the picture of any contaminated water working into the drinking supply.

What contaminated water from where ?

 

[ragsta]

I'm concerned at point 1 in the picture of any contaminated water working into the drinking supply.

What contaminated water from where ?

Hi, Just in general water from the toilette cistern, don't fully understand how it works. Just being cautious.

Fast reply - Thanks.

 

[seco services]

You won't get backflow from the toilet cistern as you will have an air gap between the fill valve and overflow, This acts as a backflow prevention.

ie same as a basin tap is higher than the overflow of basin so water can never go back up a tap.

 

[ragsta]

Oh i got it, the analogy helped Thank you. Does the rest look sound ? assuming the pressure is all ok

 

[seco services]

Yes looks ok.
What you doing about the 7m run of waste pipe from DW/new sink to drain/stack ?

 

[ragsta]

Hi, The eventual distance from the sink area will probably be 5m ~ to the drain on the other corner.
Its going to come out at a good angle, then slope at least 40mm a metre into a drain with some sort of trap (I think this needs to be roddable ?) Then this will feed into an existing drain extended with a 110mm pipe. Its about 4-5m metres away at the moment. The toilette will connect into this new extended pipe. I just hope the original drain connects via a 100 - 110 mm pipe to the existing soil stack which has a vent.

Thanks for helping especially so late

 

[seco services]

Yes ok.

40mm waste should really only be 3.0m run.

 

[ragsta]

hey, i've taken a closer look at it. The gulley may need to be moved around the corner to use with a 50mm pipe at 4m length for sink and appliances. What i don't understand is- how is the sewage pipe rod-dable if the p trap is installed, i'm being thick lol.
Pipes will be solvent welded and bedded in pea shingle at 30mm slant per 1.2m. I'm hoping theres a link between gulley one and the soil pipe and that its 100/110mm. Does the idea look good ? maybe gulley one can even be taken out and the rain water diverted as its just for a small section. Thanks alot

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• ragsta
• 23 Feb 2012
• 1

 

[Hugh Jaleak]

Underground drain is all 'push fit' joints, need to allow slight movement to allow for ground movement. Bed is peagravel as you've said, 1:40 fall is adequate. Bottle gulley has a 'built in' trap, you wont need another. Just connect it straight to the drain, the rodding access is within the gulley should it ever be needed.

I'm assuming the proposed new run of drain will be external, so toilet will need an inspection chamber where it joins the run. Make sure when connecting new drain it is a foul or combined sewer you are connecting to and not a surface water drain! Building Control will need to inspect all drainage works anyway, so you need to design/install it in a manner acceptable under Building Regulations.

 

[ragsta]

Thanks Hugh and Seco. The new drain is external yes and i'll confirm things with BD.

1.The design in the picture is that better ?
2. i guess it will need to be slightly angled because of the diameter of the chamber.
3. I believe the existing pipe is combined foul and surface water capable, ill check.
4. the toilette pipe will exit ->bend 87.5 -> 0.5m down -> bend 87.5 and into inspection chamber. This ok ?
5. Cant find a double inlet chamber - can i block the third - is there a cap ?
cheers

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• ragsta
• 23 Feb 2012
• 1

 

[Hugh Jaleak]

1. Yes! (Thankyou. )
2. Thats fine. Building regs allow the use of a bend immediately outside a manhole so any slight adjustments on direction are easily achieved.
3. Good idea, you'll soon find yourself in trouble if you cross connect foul to storm, and will be made to correct it at your expense anyway....
4. Yes.
5. Five ('Double') inlet chamber: http://www.screwfix.com/p/floplast-d910-5-inlet-inspection-chamber-base-450mm-black/76369 Chambers usually come supplied with blanking plugs, remove from inlets you want to use.

Doesn't look like you need that though, 3 inlet will suffice (and be cheaper!) depending on depth of sewer. Use the 'straight through' connection for gulley and branch for W.C. Set on a base of concrete and haunch with concrete to hold chamber in situ when connections are made and you're happy with falls etc.