Help with Drainage on silt
Posted: Fri Dec 02, 2022 2:26 pm
Hey all,
I am currently in the process of planning a new patio, Having ripped all the old stuff out and dug down in an area ive turned my focus to sorting out drainage.
My initial plan was some french drains and a soakaway using crates. I have a fairly small area i can put the soakaway due to the 5m rule.
I started digging a test hole with a 1ft bucket and go down to a depth of 1.3m to test the ground and water table... it didn't go well.
The ground is pure sand/silt, i found the odd clump of clay at the top but its rare.It wouldn't look out of place in a ton bag at the builders merchant. The water table is high (500mm) and the hole was collapsing in dramatically. Ended up being over 1m wide.
Then it rained, the hole filled to the top and everything turned into a pond. I expected the hole to drain back to the water table but it hasn't, weeks later its still higher than the water table (it's a few inches off the top).
It seems like the ground is not draining well at all. I don't have mains drains here, the water runoff for the roof goes via a iffy looking pipe into a ditch next door - im not sure it will take the extra runoff from the patio, especially if it clogs with silt.
I have a good size garden but its 2ft higher than the patio. The road/front of the house/house and patio are all at the same level.
https://photos.app.goo.gl/bdJxTwGGRHXFiZ4c9
This isnt my area of expertise and I would like to get it planned out correctly before I start laying down any MOT - any advice would be much appreciated.
I am currently in the process of planning a new patio, Having ripped all the old stuff out and dug down in an area ive turned my focus to sorting out drainage.
My initial plan was some french drains and a soakaway using crates. I have a fairly small area i can put the soakaway due to the 5m rule.
I started digging a test hole with a 1ft bucket and go down to a depth of 1.3m to test the ground and water table... it didn't go well.
The ground is pure sand/silt, i found the odd clump of clay at the top but its rare.It wouldn't look out of place in a ton bag at the builders merchant. The water table is high (500mm) and the hole was collapsing in dramatically. Ended up being over 1m wide.
Then it rained, the hole filled to the top and everything turned into a pond. I expected the hole to drain back to the water table but it hasn't, weeks later its still higher than the water table (it's a few inches off the top).
It seems like the ground is not draining well at all. I don't have mains drains here, the water runoff for the roof goes via a iffy looking pipe into a ditch next door - im not sure it will take the extra runoff from the patio, especially if it clogs with silt.
I have a good size garden but its 2ft higher than the patio. The road/front of the house/house and patio are all at the same level.
https://photos.app.goo.gl/bdJxTwGGRHXFiZ4c9
This isnt my area of expertise and I would like to get it planned out correctly before I start laying down any MOT - any advice would be much appreciated.