French drain query

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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mo-uk
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Post: # 101946Post mo-uk

Hi

I am looking to drain water away from the foundations of my house wall. Previously it was all mud there so I could have plants but the front wall was rebuilt and it was all infilled with solid material which will make it hard to dig it all out and put soild back in. So I intend to just have gravel/shingle there and create soem form on drainage underneath.

I have read a lot on the site and am going to go with a french drain with consists of a plastic pipe in gravel that will collect the water and take it out into my lawn through additional pipes.

Now most of these systems seem to use one long pipe but I want to do it slightly differently - as shown in picture below as 1.

Either have a pipe running parallel with the house to collect the water in a perforated pipe and then drain off down solid pipes - or just have pipes running straight off perforated at one end (2 in picture).

I indeed to use something like downpipes as I can connect them I assume.

Is it OK to just use 10mm or 20mm shingle all over without mixing?

As shown in the picture the pupe pipes are the drain pipes (one has ended up black for some reason) and they go under a path.

One other way is that I have oen continuos pipe which runs parallell and then comes out - but this means all of the water comes to one place - whereas wih my idea above I can spread it into multiple trenches.

If I go for the flexi roll perforated stuff can you buy T connections liek i woudl need for method 1? Or shall I just make my own solid plastic ones out of downpipes for guttering?

Image

Dave_L
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Post: # 101947Post Dave_L

For a French drain you need to use a 40mm clean stone, use the flexible perf pipe on a roll and bastardise tee's etc to make your junctions.
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Captain Concrete
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Post: # 101948Post Captain Concrete

Its not a bad idea to line the trenches with a porous terram, to help keep the shingle from contamination.
Been in concreting for 22 years

mo-uk
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Post: # 101949Post mo-uk

I think my builders merchants only sell 10mm or 20mm shingle - would 40mm be under some other name?

I spose on the bits where water is transported I could use the stuff on a roll but obviously i dont want the water to come out of the holes as it is being transported away.

Wil have to look into how to make a tee.

Captain Concrete
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Post: # 101950Post Captain Concrete

it can be called reject single, we get it direct form Hanson, Days or Gallagher depending on where we are.
Been in concreting for 22 years

seanandruby
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Post: # 101975Post seanandruby

You could use a geocomposite membrane hydroduct sheeting ,maybe hydroduct 220.
sean

mo-uk
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Post: # 101992Post mo-uk

I had to order a skip so at the same time I ordered my shingle for the french drain - it was advertised as 20mm recycled shingle and suitable for draining as it has 'no fines'.

I got it today and it looks like this - http://1drv.ms/1x7rEyi

To my mind the very small particles look like they will clog things up and it should have been large stones only which is what I was expecting. Have they sent me the wrong thing?

I had to spend AGES shovelling tons of it out of the skip so won't be pleased if it is the wrong stuff.

That said I need to have a couple of footpaths laid so could I use that as an alternative to MOT type 1?

In theory I could remove the smaler particles by washing what I have but it will take ages. I will ask the supplier - if its the wrong stuff then maybe they will deliver what I need for free.

Note - the pciture I have shown shows a lot of smaller particles- probably not the best representation as other parts have more larger stones and less smaller particles.

msh paving
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Post: # 101993Post msh paving

20mm is to small not enough free space , it wont work as well as it should MSH :(
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mo-uk
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Post: # 102412Post mo-uk

ok i have one ton of 40mm shingle- stuff is massive

I will need to look up how much there should be unbearthe in the area I want to drain away from - not much I suspect

I am concerned about the perforate pipe crumbling under the weight - I have the 80mm stuff.

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