Land Drainage

[WabbitPoo]

Just one thing to be wary of - if your garden is lower than those of your neighbours there's a good chance you will drain their plots too, and so on up the road.

That's fine if a) your soakaway and drains can take it and b) they don't mind you draining their lovely, specially-planted bog garden!

 

[britishrallying]

Nah all gardens on the same level, althpugh its a good point about bog gardens etc, will have a look over the fences first

Cheers

Gaz

 

[Mattartist]

Hi guys

How's it going britishrallying? Have you started?

Redpis: great work, looks excellent and high quality.

Posting as I've a similar problem - i.e. no drainage in a clay soil.

In short the water table rises to the point where it flows into my conservatory and lounge sub floor - (the result of this plus no ventilation was a rotten floor which I've since rectified and replaced).

Inside the lounge

• Mattartist
• 13 Feb 2009
• 1

Had to replace the entire timber floor which was rotten. There was no ventilation as air bricks...

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• Mattartist
• 13 Feb 2009
• 1

New floor. Ignore the moving-in clutter!

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• Mattartist
• 13 Feb 2009
• 1

My task now is to divert the ground water and prevent the water rising so high.

Before we bought the house!

Before we moved in

• Mattartist
• 13 Feb 2009
• 1

Investigating and digging

Seeing what's happening near footings

• Mattartist
• 13 Feb 2009
• 1

Found a "soak away" at footings!

• Mattartist
• 13 Feb 2009
• 1

Down pipe at far corner rain into underground drain which just rain into this 2ft pit! Poor...

Found the conservatory down pipe led to this poor excuse for a soak away at the corner of the conservatory! Must've been cowboys. This pit, and others I've dug, fills up from underground after heavy rain.

"soak away" filled up after heavy rain

• Mattartist
• 13 Feb 2009
• 1

The good news is that I've an existing man-holed drain in the garage (the lean-to with patio doors far right of the image above) which can take the water away. I'll need to break into this somehow.

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• Mattartist
• 13 Feb 2009
• 1

I'm only really concerned with pipe runs around/ near the house perimeter at the moment so water doesn't come in and I can crack on with finishing the house. I will probably add to the drainage network laying drains in the rest of the garden when we come to landscape it

I'd be grateful for any advice and I'm sure I'll be back asking for more help, but my questions (after all this rambling!) are

1) as daft as it sounds I'm having real trouble finding a supplier of the perforated pipe and fittings. Been passed between Drain Centre, Pipe Centre and PLumb Centre with no joy!! Where did you guys go?
2) Redpis, I had planned to use geo membrane, as was quoted by a contractor too, but from what Thermo says worries me. Has your experience led you to think you wouldn't use the membrane if you did it again?

Cheers guys
Matt
[/i]

 

[Thermo]

you wont get it from a plumbers merchant because plumbers dont get messy doing drainage. you should be able to get it in 25m or 50m coils from any decent builders merchants. Expect to pay about £45-55 a roll. dont worry about getting the fittings for it, just use normal drainage fittings and slot the pipe in the end

we dont use geotextile, especially in clay soils as it can clog up far too easily. Lost count of how many weve done now

 

[Mattartist]

Appreciate your reply Thermo.

I'm probably going to include an inspection chamber where the pipes meet before going onto the manhole in the garage. Do you think that this would be suffice or a recommended alternative for to collect any silt?

Thanks
Matt

 

[Thermo]

you could do, youll be surprised at how clean the water is when it gets into the pipes. Were doing one at the moment thats taking all the run off from a heavy clay soil and drains into a pond. the surface water that goes straight into the pond can be seen when it rains as it is a dirty yellow colour. The stuff that filters down through the gravel and into the land drain flows out from the outfall pipe virtually clean. Ill post some photos when i get a chance

 

[Mattartist]

Hi Thermo,

you wont get it from a plumbers merchant because plumbers dont get messy doing drainage. you should be able to get it in 25m or 50m coils from any decent builders merchants. Expect to pay about £45-55 a roll. dont worry about getting the fittings for it, just use normal drainage fittings and slot the pipe in the end

I've sourced the drains at a builders yard, thanks. Although I notice it's 80 or 100mm. Yet the underground Hunter fittings are 110mm. Can I ask how you normally make up for the excess diameter when connecting these fittings?

THanks

MAtt

 

[Thermo]

dont worry. the pipe just threads into it with a loose fit. youre not looking to get a watertight fit as with normal drainage. use the 100mm pipe by the way

 

[bdlegas]

hi guys, brilliant info you've been giving

i'm donig the same to my garden now ( although only on one side, as i've decided to go with the flow and have a bog garden)

i'm draining the sunny side, so the kids can get out there for more than a few months a year. the problem i've got is, can i bust into an existing clay land drain pipe, and whats the best way to do it. its surrounded by concrete at the moment, which i've chipped away, but its connecting the new ( plastic 100mm) pipe to it. a mate of mine said to just offer it up and concrete round the joint. will this work? and is it legal?

 

[Thermo]

yes it will work and yes its legal as its only a land drain. Where does the xisting land drain discharge to?

 

[bdlegas]

chers thermo, for the reply. i've got no idea where it goes, under the neighbours fence and under a previously existing extension, so no way of telling.

ps, i've got straight 4" soil (orange ) pipe that was on offer. any idea what size hole is optimum? ovviously smaller than the pea shingle (20mm) but not too small to block up. i was thinking 8 to 10 mm. any ideas? and is it a definate no no with the landscape fabric? i've looked on a few other sites, and its recommended ( as in http://www.pavingexpert.com/drain03.htm )

cheers for your time; its really appreciated. i think i owe it to the community to post a few notes/ pics of how i sucessfully managed to put a wet room in an upstairs bathroom, and it aint easy1

cheers again

baz

 

[TheSalad]

Great work !!

 

[TheSalad]

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[LeadFarmer]

An interesting thread.

Britishrallying, let us know how you go on, I would like to do a similar project myself, so you can be my guinipig if you like

Good luck

 

[Netto]

I've discovered the problem with the drainage on our back garden...About 3 ft of MOT, underneath the usual new-build garden of soil/turf mixture of clay, mortar, and broken house bricks...

Joy...