EXTENSION_DRAINAGE DESIGN

Foul and surface water, private drains and public sewers, land drains and soakaways, filter drains and any other ways of getting rid of water.
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77-1093879544

Post: # 257Post 77-1093879544

Hi Tony

First of all I must congratulate you on a BRILLIANT! Site its the best I have seen for us DIY,ers and to think I paid a subscription to a web based home build site that has only a fraction of useful data, I want my money back.


I am in the process of building an extension to the side of the house and am going to scrape down the earth to below DPC in preparation for trenching. As the house is some 70+ years old I was thinking of replacing the combined drainage system for foul /sewerage. The reason being the new garage and kitchen will be built over the drains. The present configuration has a soil pipe and one hopper type drain for the old kitchen and down spout. The Garage will be built around the existing wc soil pipe.

Is it permissable to have a rodding point within a garage or should I be putting in a rodding eye which will have to be further away about 6m near to a P trap hopper for new kitchen waste water/ rainwater drainage.

Finally, Is it permissable to have the piping cross a foundation currently 900mm, although I,m not sure yet at what depth it will cross at. Do I need place pipe beneath a box or lintel type structure?

Regards

Mike

84-1093879891

Post: # 261Post 84-1093879891

Hi Mike,

thanks for the compliments. It's good to know that you find the site useful. :)

Right then, your questions....the Rodding Eye - this is best positioned at the head of a run, so, if you have a line coming up the side of the house, serving the downspout and the Kitchen Waste, then the rodding eye should either be adjacent to the last upstream fitting, or at the end of the straight run.

The key determinant is that you must be able to get to ALL parts of the system with rods. If you have access from downstream via an IC or MH, then a rodding eye might not be essential, but I can only really say what is best if I had a sketch plan of your layout. If you want to send me a sketch, as a gif file or similar, I'll upload it to this thread and add my comments accordingly.

Secondly - the foundations over an existing drain. This is covered by Part H of the Building Regs and you need to speak to your local Building Control Office to see what they recommend. The usual craic is a lintel bridge over existing sewers, but, as you say, it all depends on depth. Where a sewer/drain would run through a concrete footing, rocker joints can be used to isolate the section of encased pipework, but again, you need to ok all this with the BCO.

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