Browse Forums Building Standards; Getting It Right! 1 Feb 05, 2015 5:41 pm What is the required storm water sub soil drain size for your average 3 bed new home of about 25 squares? 100mm? Is 90mm non compliant in most, if not all, circumstances? Can someone point me in the direction of the associated regs regarding this matter? My drainage designs and slab design are yet to be done and I am at soil test stage in the next few weeks in Aurora Wollert, with Simonds Homes. Wollert is an area mostly of highly reactive clay soils and plenty of sub soil and surface rock. Thanks. Re: Storm water sub soil drain size to comply with relevant 2Feb 05, 2015 7:01 pm You seem to be confusing two separate things: Stormwater Drains - These take the roof drainage and any path drains to the approved point of discharge. They have to be designed based on the flows from the roof and hard areas taking into account the gradient of the pipes. Sub Surface Drains - These only take the flows from underground which are relatively small for a typical suburban block so a 90mm pipe would probably be OK. The sub surface drains should discharge into the Stormwater drains at some point The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Storm water sub soil drain size to comply with relevant 3Feb 05, 2015 8:29 pm Ok thanks for clarification and I am aware of your qualifications so thanks. I was really just referring to the drainage that will come from the roof area and from the concrete apron I will be placing entirely around the house with the required fall and including spoon drains into the proper discharge points of the drain that will go underground to the point of legal discharge. That is what I meant and not any other subsequent ag drains. So that being the case, the 90mm thin walled pvc pipes are quite acceptable and compliant for those storm water drains versus the 100mm pvc heavier walled pipes. I am paying a lot extra as I requested to have Stormplastic expanding joints and swivel joints I know as per my contract, I was just hoping 100mm pvc pipes would be used but if the 90mm pvc pipes along with the expanding and swivel joints are acceptable I guess that is all Simonds Homes will be going with. I am in a highly reactive clay soil area of Wollert Melbourne on a waffle pod slab. Re: Storm water sub soil drain size to comply with relevant 4Feb 05, 2015 8:47 pm For stormwater drains you can get the 90 mm uPVC storm water pipe with a rating of SN4 which should be OK for below ground applications. Typically this is 2.5mm thick I wouldn't recommend used SN2 rated pipe below ground level as I think its far too flimsy. The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Storm water sub soil drain size to comply with relevant 5Feb 06, 2015 7:20 am Thanks Bashworth, that is the information I was hoping to obtain, now I can see what gets specified on the engineering plans for drainage and make sure I get the SN4 versus the SN2 if it specifies 90mm uPVC for those drains. Then it will be a matter of checking on what gets used by the plumber is what gets specified before it gets buried. I need to make sure the Stormplastics joints are also used. I am paying $1600 extra for the Stormplastic joints as an extra on my contract. I would be even happier if 100mm is specified in the drawings too of course but we are talking a volume builder here. Regards and thanks again. thanks guys! yes this is how I've exactly raised it with the builder. still awaiting response. 12 6026 Hello I am developing 2 side by side units. Wish someone can help me on the following questions 1) Which stage should be the storm water pipe installed during the new… 0 7787 If you need to be able to access these then you may need to dig them out and cut them so you can add a socket and a riser to the required height. We normally add a… 1 6827 |