Hello,
After completing an extension last year my next project is to start the patio at the rear of the property. There is already 150mm type 1 MOT in the area (needs compacting). I've had 3 quotes for the same thing (probably honed Indian stone) and all 3 have said channel drain along the house to the existing gully trap as shown in the picture. I've dug the trench for the drain and a trench for some wooden sleepers that will be used to separate the patio from the lawn. This will have a slight step up to the lawn, approx. 50mm.
Having spoken to some drainage engineers and reading various forums/blogs there seems mixed views in sloping the patio TOWARDS the property. Note that the top of the aco drain will be 150mm below DPC (in line with the trench block in the image). Did the 3 quotes say channel drain along the house simply because of where the gully trap is thus making it easier to connect to? Am I creating a problem that doesn't exist here by directing water towards the house?
Drainage calcs for patio area state the channel will be 83% full for 1:100 year event.
Any advice is greatly appreciated.
https://ibb.co/4gqwjV3
After completing an extension last year my next project is to start the patio at the rear of the property. There is already 150mm type 1 MOT in the area (needs compacting). I've had 3 quotes for the same thing (probably honed Indian stone) and all 3 have said channel drain along the house to the existing gully trap as shown in the picture. I've dug the trench for the drain and a trench for some wooden sleepers that will be used to separate the patio from the lawn. This will have a slight step up to the lawn, approx. 50mm.
Having spoken to some drainage engineers and reading various forums/blogs there seems mixed views in sloping the patio TOWARDS the property. Note that the top of the aco drain will be 150mm below DPC (in line with the trench block in the image). Did the 3 quotes say channel drain along the house simply because of where the gully trap is thus making it easier to connect to? Am I creating a problem that doesn't exist here by directing water towards the house?
Drainage calcs for patio area state the channel will be 83% full for 1:100 year event.
Any advice is greatly appreciated.
https://ibb.co/4gqwjV3