Browse Forums Building Standards; Getting It Right! Re: Drainage after build 2Jun 21, 2015 9:02 pm Depends on what was in the contract. Is your stormwater fully connected? You may also need some surface drainage in addition to the roof downpipes. BLOG: http://www.ourphoenix38.blogspot.com.au H1 THREAD: viewtopic.php?f=31&t=70454 Re: Drainage after build 3Jun 22, 2015 8:13 am Hi Crazyk, The NCC does state under Performance requirements P2.2.1 Surface water that: c) A drainage system for the disposal of surface water resulting from a storm having an average recurrence interval of— (i) 20 years must— (A) convey surface water to an appropriate outfall; and (B) avoid surface water damaging the building; but I'm wondering how to interpret the first part of this. Does this mean it only applies after an unusually heavy downpour or any surface water. Does anybody know? Aside from this, 3.1.2.2 Surface water drainage surely applies: Surface water must be diverted away from Class 1 buildings as follows: (a) Slab-on-ground — finished ground level adjacent to buildings: the external finished surface surrounding the slab must be drained to move surface water away from the building and graded to give a slope of not less than (see Figure 3.1.2.2)— (i) 25 mm over the first 1 m from the building in low rainfall intensity areas for surfaces that are reasonably impermeable (such as concrete or clay paving); or (ii) 50 mm over the first 1 m from the building in any other case. Though now I suppose the question becomes how far away is "away from the building"! Re: Drainage after build 4Jul 13, 2015 9:01 am It should be graded away but I think it is virtually always a landscaping issue. If a builder grades the surface the Owner usually then changes the area by landscaping paving etc. Re: Drainage after build 5Jul 13, 2015 4:58 pm leighton It should be graded away but I think it is virtually always a landscaping issue. If a builder grades the surface the Owner usually then changes the area by landscaping paving etc. Yes but then any issues will be that of the owner not builder. Re: Drainage after build 6Jul 21, 2015 8:58 pm Was there a photo in the opening post? 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 7Jul 22, 2015 6:04 am Yes there's a pic there, I can see it with tapatalk. Sent from an elegant mobile device using Tapatalk. My forum thread is at viewtopic.php?t=74944 Re: Drainage after build 9Jul 22, 2015 7:38 am That definitely does not comply with the NCC as it stands. And falls into the category of building work not landscaping IMO. Whatever a client chooses to do after handover, presuming they have been given the correct information about fall (and not the information contained in the CSIRO document on maintaining Footings) can certainly be put at the feet of the client. But this isn't the case here. And look at those wrecked temporary downpipes! Re: Drainage after build 10Jul 22, 2015 10:25 am Oh, temp downpipes were a token gesture. they didn't work even when connected as the kerb outlet was blocked and water just backed all they way up the system to the lowest point...junction of downpipe to PVC and kept flooding the site for 10mths. I just hope that I don't succumb to long term slab heave. The kerb outlet has since been unblocked due to my neighbour complaining about my overland flow of water entering his property, on the other side. Re: Drainage after build 12Jul 22, 2015 12:36 pm It looks like un-compacted fill over the first metre. 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 13Jul 22, 2015 1:08 pm @SaveH2O - you are correct, the fill in uncompacted even up to the foundations @Stewie D - While I don't have a particular site plan with drainage as such, My Slab Engineering reports says "Adjacent ground shall be sloped away from the foundations to prevent ponding, falling 50mm in the first meter outside the footprint to a spoon drain or slotted dia90 pvc drain in scoria or coarse screenings which is to discharge to a min 300 x 300 grated pit in which in turn is to be connected via min 90 diameter pvc to the legal point of discharge Personally I think it's quite clear, site drainage doesn't comply with the slab engineering requirement do you agree? Re: Drainage after build 14Jul 22, 2015 3:36 pm I am sure that the slope cannot be un-compacted soil but I don't have access to the regulation. Un-compacted soil is permeable. I can even see sand! 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 15Aug 02, 2015 7:39 pm Crazyk @SaveH2O - you are correct, the fill in uncompacted even up to the foundations @Stewie D - While I don't have a particular site plan with drainage as such, My Slab Engineering reports says "Adjacent ground shall be sloped away from the foundations to prevent ponding, falling 50mm in the first meter outside the footprint to a spoon drain or slotted dia90 pvc drain in scoria or coarse screenings which is to discharge to a min 300 x 300 grated pit in which in turn is to be connected via min 90 diameter pvc to the legal point of discharge So do you think based on the above quote that I should be pushing the builder to install spoon drains and pits? Re: Drainage after build 16Aug 04, 2015 7:45 am It would depend on the contract, it is clearly unfinished and can be easily resolved with landscaping. When I look at this I will say that this is unfinished work and no spec in contract stating that the external area needs to be completed. The NCC does not come into force here as it is yet unfinished. Re: Drainage after build 17Aug 04, 2015 7:45 am Crazyk Crazyk @SaveH2O - you are correct, the fill in uncompacted even up to the foundations @Stewie D - While I don't have a particular site plan with drainage as such, My Slab Engineering reports says "Adjacent ground shall be sloped away from the foundations to prevent ponding, falling 50mm in the first meter outside the footprint to a spoon drain or slotted dia90 pvc drain in scoria or coarse screenings which is to discharge to a min 300 x 300 grated pit in which in turn is to be connected via min 90 diameter pvc to the legal point of discharge So do you think based on the above quote that I should be pushing the builder to install spoon drains and pits? I don't think you have a leg to stand on if it is not on the drawing. Re: Drainage after build 18Aug 04, 2015 10:50 am What do you mean it's not on the drawings? It's in the slab drawing and on that has a list of specifications one of which I quoted above ? I would of thought an engineer designed slab drawing is good enough and the builder must follow those guidelines. Re: Drainage after build 19Aug 04, 2015 2:05 pm Crazyk What do you mean it's not on the drawings? It's in the slab drawing and on that has a list of specifications one of which I quoted above ? I would of thought an engineer designed slab drawing is good enough and the builder must follow those guidelines. Just to be on the same page, you are talking about drainage to the side of the house, this is not covered in the slab design, it is dependent on the finishing contours of your landscaping and stormwater design. As such, if it has not been designed in the stormwater plan and landscaping work is out of the contract then the contractor is not obliged to finish off the side of the house. Re: Drainage after build 20Aug 04, 2015 3:57 pm I'm referring specifically to the quote below which is contained in my slab engineering report: Adjacent ground shall be sloped away from the foundations to prevent ponding, falling 50mm in the first meter outside the footprint to a spoon drain or slotted dia90 pvc drain in scoria or coarse screenings which is to discharge to a min 300 x 300 grated pit in which in turn is to be connected via min 90 diameter pvc to the legal point of discharge I'm not talking landscaping at all. I'm merely trying to ascertain that if the engineering report says that all ground needs to be sloped away from the house and drain to a pit which in turn discharges to a LPOD, should I be forcing the point with the builder to instate the pits and drainage system. I do not have a specific drainage plan that shows where all the stormwater pipes go. Hi HomeOne, I'm in the midst of landscaping a cat run down the side of my house, and the recent rains have me wondering if I need to install some sort of drainage. I've… 0 12280 2 5843 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 3147 |