Patio linear drain against retaining wall

[buk]

I need to arrange to remove water from my patio that will flow towards a retaining wall between the patio and the lawn. Away from the house.

I've looked at the cost of linear drain units from Clark and Savage, and find it prohibitive. I'm also not particularly keen on the look of them either.

My ideal solution would be Gatic paveslot as I like the discrete nature of the narrow continuous slot at the base of the wall, but these units are hugely expensive (£270+/3M unit). They also would require digging much deeper into the chalk bedrock as the minimum unit is 252mm deep + bedding.

As I have more time than money, I'm considering achieving a similar effect to the slotdrain by forming a channel at the base of the wall and overhanging the slate pavers leaving a 10mm gap. It would look something like this ('scuse the ascii art):

Code: Select all

Retaining wall         =======      Lawn
                                |      |""""""""""""""""""""""""""
                                |      |oooo
Slate overhang          &#124;      &#124;oooo <- Terram wrapped gravel
10mm gap         ---&#92;  &#124;      &#124;oooo    with slotted drain 
                              v &#124;      &#124;o&#40;&#41;o
=============== &#124;      &#124;oooo
            //////////////&#92;_/////////
            ////////////////////////
                         ^
                         &#124; Gully formed in c7.5 concrete 
                           benched with mortar to achieve slope.

Thoughts?

If the idea is viable, what dimensions should the gulley have?

Many thanks, Buk[/color]

[Tony McC]

Nowt wrong with that, but that 10mm gap will require fairley regular cleaning.

One 'tip' you may find useful: get a length or two of 63mm half-round guttering and bed that into the concrete rather than trying to form a channel with mortar.