Land drain under path? - ...is this wise

[losttheplot]

Hi. We live on a hillside with clay soil and have a house to one side which is much higher than us. Consequently we have a water-logged garden every time it rains. Next to the partition wall (that stops their garden falling into ours), we have a shed and a greenhouse, then a path that runs the length of our garden. Are we safe to dig a land drain under this path if we top the trench with a weed barrier and slate chippings? Any advice would be most appreciated

[lemoncurd1702]

Under the path or next to? What is your concern in doing this.

[seanandruby]

So once you dig up your path, dig a trench, fill it with
Whatever and reinstall the path what do you hope to acheive by this??? At the top of the drainage page is a post by the boss, i suggest you read that and all the leads he gives. Because we don't know your particular sub soil type it is hard to give you a solution. You need somewhere to drain to ie soakaway, or set up a pumping system to cope with it. Also photos's sometimes help but not to often with problems like yours. Good luck and keep us informed

[losttheplot]

Thanks. My concern is that the land drain might not be effective with a path overhead. My hope is that we won't have to dig up the lawn, and that we also won't get a dry line down the lawn in the summer. Is it the case that any ground water leaches in to the drain's trench from the sides, so it doesn't matter what's on top? As for the soil type, it is heavy blue clay (Welsh mountainside), and as for the outflow, we have uncovered a deep land drain that was incorrectly laid when the site was first developed. It has no gravel or membrane round it, so it is useless, but it does run off-site and exits over a road-side drain. We have checked that the perforated pipe is clear and that water flows through it, so we will join our drain onto this existing one.

[seanandruby]

I'm assuming your path isn't paved? Think you have answered your own question really in upgrading the filter drain. At least it runs off site so should go to a soakaway, or drain. Maybe you can give the grass a good forking nice and deep.

[losttheplot]

Sorry, I don't understand! Allow me to rephrase my question: Is there any reason why I should not lay a land drain directly under a garden path (following the same course down the garden), consisting of a weed barrier topped by slate chippings?

[lemoncurd1702]

Sorry, I don't understand! Allow me to rephrase my question: Is there any reason why I should not lay a land drain directly under a garden path (following the same course down the garden), consisting of a weed barrier topped by slate chippings?

Does the path have a solid surface i.e. concrete or is it currently, or going to have a loose permeable surface i.e. gravel.

[losttheplot]

Does the path have a solid surface i.e. concrete or is it currently, or going to have a loose permeable surface i.e. gravel.

The path will NOT have a solid surface.

[seanandruby]

Sorry m8. You would be better suited putting the drain trench at the sides of your path down 200/300 and camber your path for surface water to run off. Use geo-membrane not weed barrier.

[losttheplot]

Thanks, but a non-solid path made of slate chippings has no camber, or surface water. However, it's probably a good idea to use geo-membrane under the gravel and chippings.

[rxbren]

From all your posts im guessing what you want to hear is yeah that will be fine but......


If the water logged area is not the path you won't gain much putting the drain in the path you need the drain to start uphill and go through the area that is water logged plus depending on your garden you may need a series of drains.

There is a chance you may get some discolouration in very dry weather but its that or the water logged garden

[seanandruby]

Surely you will be using a sub base in your path? That will be laid with a camber ???

[losttheplot]

OK, I'm no path expert, but from what I've been told, our new path (that will run directly over the most waterlogged part of the garden i.e. nearest to the higher ground) needs to be no more complex than cutting and removing the turf and some earth/clay, pegging in battens along the sides, laying a weed barrier (geo-membrane will be fine for this), then chucking in about two inches of slate chippings. It's just a very simple path on solid clay ground and even if we lay it with a camber, that will go the first few times it is walked on. So, no sub-base and no camber - just slate chippings on a membrane.

Only now we're thinking that if we're going to lay a land-drain down the length of the garden, and we've already dug the path of the path so to speak, and that path of the path runs through the wettest part of the garden, we might as well dig the land-drain along the same path (of the path) and then top the land-drain trench with the new path (membrane and chippings). Thus we only end up digging one trench.

So my thinking is that as the path will let rain water through, that it won't be a problem that the drain has the path over it, but as I am aware that one doesn't know what one doesn't know, I thought I'd run it past you guys and girls first, just to make sure that I'm not missing something.

[lemoncurd1702]

Give us a photo or diagram LTP, I think we are all seeing a different plot in our minds eye.
A picture says a thousand words

[lemoncurd1702]

Sorry m8. You would be better suited putting the drain trench at the sides of your path down 200/300 and camber your path for surface water to run off. Use geo-membrane not weed barrier.

Sean, do we really need a camber on a path thats probably no more than a metre wide?