Drainage question

[hodgsp]

Scoured the other posts on drainage problems and can't seem to see anyone trying what I'm looking to do .....

The very top part of my garden has a patio area with a shed sitting on a slightly lower set of slabs. Rain water backs up behind the patio and floods back onto the slabs and back onto the lawn .... trading the lawn and routing the shed.

From the house I've cut into the underground drainage system which is fed from the gutter downpipe .... adding a t junction with a length of pipe heading away from the house, under the patio up into the lawn.

The remaining ideas was to run pipe work from the top of the garden to this piece of pipe . if scrounged around and got enough of the 110mm plastic piping to complete the project.

Questions are :

1) is there any need to worry about more water finding its way into the trench I'll be digging to put the pipe work in ..... I don't like the idea of giving water a conduit towards the house.

2) filtering ..... Do I nneed to filter out any soil etc before it enters the pipework or should pipework of that size bed flush itself with a decent amount of water through it

Cheers

 

[Newboy]

1) No

2) A trapped gully otherwise you run the risk of blocking the pipework

 

[r896neo]

There absoultely is a concern about creating a nice easy path for water to run down the trench.

This is why you need to try to block off the path of water with concrete at some point in the trench or similar. Its hard to give specific advice without seeing your layout but as a general rule water will take the path of least resistance.

Obviously it will find its way most easily;

1. into open space (such as a gulley or pipe
2. into some kind of granular fill with voids such as gravel
3. into loosened/ disturbed soil
4. into virgin compacted earth

If you consider this in your planning you won't go far wrong.