Retrofitting dished channel to edges

[mikiex]

Hi,


I am hoping I will be able to shift the water that pools against the house currently

I've decided to retrofit a dished channel replacing the edge blocks.

The person who layed the paving originally did not put in any drainage and the blocks slope towards the house.

I have not gone for a linear drain because I dont want to dig up the old gully the water will flow to, also these will fit the gap the old blocks were in nice.

At the moment the concrete blocks are layed on sand against the wall. As far as I can tell this is ok, but I wonder if I used some concrete under these blocks would this help stop water under the paving flowing towards the house. Or should I just relay them on sand?

images are here , I posted before on the drainage section
pics

Also what will stop water going between the gaps of the dished channel? - does this mean sealing and or stablising the joints
and does that mean applying to the whole of the paving?

Or is the dished channel a total mistake?

Thanks for any answers

[Tony McC]

Jaysus, that's some rough owld paving!

You should be able to replace the existing edge course with 200 x 200mm wide dished channel units. The easiest way is to take out the edge course blocks plus one additional block creating a 'gap' 300mm wide. Dig out the laying course to expose the sub-base beneath.

Lay the dished channel units on a bed on semi-dry mortar or concrete. No overriding need to mortar joint the units: if you butt-joint them, they'll self-seal with sand and detritus over time. Make sure that they all fall in one direction only, ideally towards the gully or disposal point.

Re-bed the missing blocks on fresh sharp/coarse/grit sand.

[mikiex]

Hi Tony, thanks for the reply

is it ok if the mortar I use sits against the house wall? Just worried if I ever had to remove it in the future.

Also is it worth putting in a waterproofer into the mix as I have a bottle of additive I was planning on using when I repoint the house brickwork under the block paving.

Interesting you say sharp sand for the other blocks near as I was planning on just using paving jointing sand. So I wouldnt of known that.

Also thanks for your advice and great site!

[James.Q]

the dished channel would sit next to the wall no need for mortar inbetween.

[Dave_L]

Aslong as you can get the channel tight to the wall, then no problem. Otherwise a fillet of mortar wouldn't hurt.