Browse Forums Building Standards; Getting It Right! Re: Drainage after build 41Aug 07, 2015 9:25 am What area are you in? A stormwater plan is required at DA approval stage, I am pretty mystified that you don't have one Re: Drainage after build 42Aug 07, 2015 10:16 am Kind of related...My drainage plan shows capped risers every ~10 metres but it looks like they haven't been installed. Is this something they may install later? The house is at lockup and all downpipes are hooked up. Re: Drainage after build 43Aug 07, 2015 10:57 am My council didn't really know much and the builders Building Surveyor was quite coy about it. I actually think that for my 330m2 roof area a single Class 6 DN100 PVC discharge pipe running at 1:100 fall to kerb and channel is insufficient. I just need to try and get some calculations to prove it. My builder says that 90mm is standard but because of my low fall they put in 100. If there is someone smarter than I willing to run some numbers for me can you PM me please. Re: Drainage after build 44Aug 07, 2015 11:54 am Stewie D The plumbers just look at the downpipes ( usually insufficient for the roof area to start with ) and just run their in-ground pipes the easiest way for themselves and connect these to the downpipes. Hardly a well thought out or calculated solution. I think a lot of this comes down to the local council. Yep, plus the regulations are very poor. Crazyk No all my pipes were laid pre pour. I'm at a loss. Looks to me like they just let the plumber decide either way I'll be asking for evidence the DN100 stormwater pipe is enough to take the waterfllow from my 330m2 roof plus 60m2 driveway. AS/NZS 2200 doesn't seem to be referenced very often these days for stormwater drainage flow calculations. The maximum flow rate for a DN 100mm uPVC pipe laid at the minimum 1:100 slope is 480 litres per minute as per AS/NZS 2200. Your 330 m2 roof area would need to drain much more than 480 lpm during a 1:20 ARI. Eaves gutter drainage compliance is based on a 1:20 ARI average rain intensity over a 5 minute period. Even if your single DN 100mm uPVC pipe ran charged, it is highly unlikely to be able to also drain the 60 m2 driveway but I say this without having a visual to your site. The majority of new homes in Victoria are handed over with non compliant and/or sub standard drainage for a number of reasons. Crazyk My council didn't really know much and the builders Building Surveyor was quite coy about it. I actually think that for my 330m2 roof area a single Class 6 DN100 PVC discharge pipe running at 1:100 fall to kerb and channel is insufficient. My builder says that 90mm is standard but because of my low fall they put in 100. Your builder is clueless about this subject and best practice and the other references to the council and the builder's building surveyor are a typical sad indictment on the industry. 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: Drainage after build 46Aug 07, 2015 2:08 pm It is a simple well explained beginners guide with only a couple of debatable references. A competent professional would not "use" it because they should know the contents. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. 2 6362 I would find out how deep your clay base is and depending on the depth install a cut off drain which is more than a normal agi drain. Where the neighbouring walls is… 2 3423 13 7049 |