Browse Forums General Discussion 1 Oct 09, 2020 10:33 pm Hi all, We are nearing completion on our new home, and I have been trying to tee up a concretor to provide a paving slab around the perimeter of the house to protect the slab from varying soil moisture (wafflepod slab on highly reactive clay). The site is fairly flat, with a very slight fall towards the street. The paving slab will be 1000mm wide with a 1:20 fall away from the house. Now, my initial plan was to simply allow this water to flow down the perimeter paving slab and into a small 200mm wide garden bed along the sides of the house against the fence line, and onto the lawn along the rear. Being the paranoid person that I am, I'm now second guessing myself and wondering if it should be captured and drained into the stormwater system instead (and if so, how do I do this in a simple way without heaps of excavation and plumbing required). Thoughts appreciated! Thanks. Re: Perimeter paving slab drainage? 2Oct 09, 2020 11:18 pm watchers I'm now second guessing myself and wondering if it should be captured and drained into the stormwater system instead It has to drain to a silt pit first, you can't connect straight to stormwater. It is best to have a spoon drain or similar on the path's perimeter. We are heading into a La Nina and that is scary if you have built on highly reactive soil. It has to be right. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Perimeter paving slab drainage? 3Oct 10, 2020 11:09 am SaveH2O watchers I'm now second guessing myself and wondering if it should be captured and drained into the stormwater system instead It has to drain to a silt pit first, you can't connect straight to stormwater. It is best to have a spoon drain or similar on the path's perimeter. We are heading into a La Nina and that is scary if you have built on highly reactive soil. It has to be right. Thanks for the response. How viable is letting it drain into the small garden bed and just letting it evaporate/get soaked in by the plants though? Say a 200mm wide small strip with say 100mm deep of mulch and some small succulents or something. It's not a massive catchment area. Re: Perimeter paving slab drainage? 4Oct 10, 2020 11:46 am You need to do some calculations but don't forget that you are on highly reactive clay. I personally would err on the side of caution...why risk it? 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Perimeter paving slab drainage? 6Oct 14, 2020 11:26 am Make the water go where you want it to go. It's lazy and will always go downhill. My brother had a footpath between his house and a small retaining wall. There was a space between the wall and the path approx 200mm wide. The space had a subsoil drain (ag pipe) leading to a pit. On top of this was some soil then some large rounded stones up to the surface of the path. In heavy rain the soil became saturated and water did not pass through to the pipe below. He removed the rocks to the side and then dug out the soil. He replaced the stones and topped them up with more similar stones. No more flooding since as the water can easily pass through the stones and get to the pipe and into the storm water pit and away. Yes, unless you are in a low intensity rainfall area or the area is protected from rain. Do you have access to NCC Part 2 or can you download it? I can email you a copy… 10 12458 i had the my concreters concrete right up to the fence. I have pits all along my path, so the water tends to drain away from the house and into the pits. There's only one… 7 12711 13 6602 |