If you are laying over an existing soakaway and you are doing a raised edged border how do you ensure the water drains into the soakaway?
I mean obviously you could put some kind of aggregate border between the patio and the edging but what would stop your subase from falling out from under the bedding layer along the edge of the patio that adjoined the aggregate border. would this even be an issue over time or not?
does that make sense. Would the subbase stay firm even though it had nothing to its side. Would you haunch your subbase to prevent it slipping out from under the edge of the patio? If you didn't have the space to haunch it what would you do?
All edging should be laid on and held by at least a 4:1 screed and the soakaway should either be capped with leanmix concrete or geotextile. Install a gully trap at the lowest point or use a linear channel along the edging and run the outfall into the soakaway.
Just trying to visualise this......You could lay a 150 x 50mm square top edging either flush with the paving surface or a say 50mm below so its not seen and cover with gravel. This would hold everything together and prevent any migration of subbase.
I wouldnt say haunch as it would spread out to far and may leave you with no space for the water to drain into the soak away. Hope this helps
thanks for the advice. I see exactly what both of you mean.
Unfortunately I had already done it but was concerned about stability.
What I did was haunch both which completely filled the 5" void where the stones were to go and when it dried I cut a strip away to allow drainage. In hindsite would have prefered either of the other 2 methods. Well they will call me if there is a problem and I will have to rectify if need be. It might be a case of taking up the bottom row of slabs but should only take a day, hopefully in several years or more!
