Garden drainage tap into rainwater pipe??

[bettz]

Hi i'm looking at putting in some drainage, perforated pipe gravel and membrane as our garden sits on a lot of clay.

I'm going to tap into the rainwater pipe, I'm hoping this is ok?

Has anyone done this? Would it be best to use the flexible perforated pipe or just normal pipe and drill some holes?

I'd be looking at putting the pipe diagonal with bits running into the main pipe on either side.

Also how best would it be to tap into the rainwater pipe?

 

[a1ex2001]

You can get pipe with the holes ready cut for this don't be doing it yourself!

 

[bettz]

Not sure what's going on but this is the pic I took after pulling out the shrub

And today it's now like this we only had a tiny bit of rain what's going on??? Seems to be filling up with water

 

[Windle]

Clay retains water, this will seep out into low points. Natural drainage of sorts.

You also look like you're in a new, or relatively new, build property. House builders are notorious for bad practice on gardens during construction as they will have been driving machines about compacting the soil, this should then be rotivated and a decent layer of good topsoil placed, 9 times out of 10 they don't rotivate and you get crap spoil backfill or a very shallow layer of topsoil. The compacted soil will have terrible drainage.

 

[bettz]

Yep it's a new build.

I'm about to pull the trigger and buy 25m worth of perforated pipe with 3 y junctions to branch off,along with fabric to cover the pipe.

Now I just need to work out how to tap into the drainpipe it's about 15 inches below the surface I'm hoping that's enough fall

 

[the_r_sole]

do you know where the rainwater drainage goes to? with a lot of new builds they will have a soakaway in the garden so you might end up using a lot of effort only to keep the same amount of water in your garden!

 

[bettz]

I'm not to sure but that pipe heads out towards the driveway where there's a manhole cover.

I was going to put in a soak away create at the top end of the garden but the hole where I took the shrub from is now half full of water so putting a create there will be pointless I'm not really left with much choice.

During the winter the gardens terrible constantly waterlogged and boggy having the dog doesn't help.

 

[Mercenary Keyboard Warrior]

I would do a bit more research personally on your own plot

Dig down, go deep, about 1M and see what you find, if you get below the clay level you may find sand or something far faster draining
If so you can dig a big pit, fill with gravel, (very large at bottom so half house bricks etc) and graduate up, use some perforated pipe to take the rest of the garden to this point.
Have 9-12" of topsoil over the top and you should be grand

 

[balky12]

I am suffering the same sort of thing on a new build. Clay everywhere. Plus other gardens slope towards my garden so it exacerbates everything. Made my garden pretty much flat with a retaining wall so a raised garden which meant water didn't really run off anywhere so it became really boggy.

Spoiler

I have since dug out the back border so most the water sits in that. It saves the actual garden from becoming a marsh however still looks ghastly. I keep digging downwards but haven't got passed the clay yet (~2/3 feet). I think I will just put some plastic piping in there and fill with gravel. Bring up the back border to level with the shed base and fill with top soil, plant in some thirsty trees/shrubs/plants.

I do feel your pain with the clay though. I am currently trying to find plants that will enjoy the clayness!

 

[bettz]

I would do a bit more research personally on your own plot

Dig down, go deep, about 1M and see what you find, if you get below the clay level you may find sand or something far faster draining
If so you can dig a big pit, fill with gravel, (very large at bottom so half house bricks etc) and graduate up, use some perforated pipe to take the rest of the garden to this point.
Have 9-12" of topsoil over the top and you should be grand

Well I've dug holes in 2 places now I get about a shovel & half depth down and hit solid clay then water

 

[Mercenary Keyboard Warrior]

Thats not that deep though

Your other option to test the depth is an auger, something like https://www.amazon.co.uk/gp/product...fl_title_26?ie=UTF8&psc=1&smid=A3P5ROKL5A1OLE

That will get you 1M down. Its hard with clay as its possible its 9 inches deep, but could be 9 feet, all you can do is go as deep as your willing to go

The auger is also handy for doing multiple holes, you may find you have a natural clay slope and you can use that to your advantage to drain the water

Like all these sorts of things, its luck and how much time your willing to invest to see if you can get a good solution

 

[bettz]

Thats not that deep though

Your other option to test the depth is an auger, something like https://www.amazon.co.uk/gp/product...fl_title_26?ie=UTF8&psc=1&smid=A3P5ROKL5A1OLE

That will get you 1M down. Its hard with clay as its possible its 9 inches deep, but could be 9 feet, all you can do is go as deep as your willing to go

The auger is also handy for doing multiple holes, you may find you have a natural clay slope and you can use that to your advantage to drain the water

Like all these sorts of things, its luck and how much time your willing to invest to see if you can get a good solution

Ive another spot near the fence which also pools water so I can try digging there. If I put the pit in the middle of the garden it'll be to close to the garage? Doesn't it have to be 5 metres away?

Would the perforated pipe not be easier

This is what the garden currently looks like after the rain we've had. Water starts pooling down the fence

 

[Mercenary Keyboard Warrior]

Its probably just a low point.
If you have clay you probably have a whole layer of it, if you can break through then its not too hard to beat it, but if its thick then your out of luck and will need to take more extreme action.
Even well draining soil will show water once the ground is wet, its how quickly it drains away thats the point.

 

[grahamjenks]

I'm not sure if this is accurate, but we had similar work done last year. New build, terrible drainage, we wanted a land drain under lawn and have it connected to rainwater waste on Garage (its lower than the garden and is connected to main sewer). However, the landscaper refused to connect a land drain to the main drainage. His claim was water bylaws wouldn't allow this, so he just connected to a couple of soakaways in the middle of the garden instead. This is on an 8 year old estate. To be fair it seems to have worked but just a word of warning (not that I'm sure anyone would ever know..)

 

[bettz]

Right thought I'd post an update we've managed to add drainage and we tapped into the drainpipe. Fingers crossed it works all I need now is a good downpour.

We put a good layer of pea gravel in the trench followed by the geotextile fabric then a little more pea gravel in then added the pipe which was wrapped in a geotextile sock then added a little bit more pea gravel then wrapped it round then covered with more pea gravel then top soil.

We've been adding more top soil and compost to the trenches to build them up level and have added grass seed which has started to grow already