Browse Forums General Discussion 1 Apr 13, 2021 6:25 pm I've been looking at the Queensland Development Code and the Mandatory Part M.P4.2 on Rainwater tanks and other supplementary water systems. https://www.business.qld.gov.au/industries/building-property-development/building-construction/laws-codes-standards/queensland-development-code If there are directions on how a tank has to be installed and your builder installs one on your house as an option you have purchased does this code mean he has to comply with it? How do you ensure your builder complies with it if you've pointed out requirements several times and he fails to answer let alone comply? Page 8: Wet system: insect and fauna proofing each inlet Page 9: for a tank that is supplied by a wet system, a screened rainhead is installed for each downpipe that supplies the tank to prevent leaves and debris from entering the tank. Re: Water tanks and building codes 2Apr 13, 2021 8:01 pm Ozgarden If there are directions on how a tank has to be installed and your builder installs one on your house as an option you have purchased does this code mean he has to comply with it? If the code is legislated, then it has to be complied with. Ozgarden How do you ensure your builder complies with it if you've pointed out requirements several times and he fails to answer let alone comply? Contact yor State plumbing regulatory body and ask for an inspection. Was a Certificate Of Compliance issued? I am not in QLD and so I am not sure on their modus operandi. Ozgarden How do you ensure your builder complies with it if you've pointed out requirements several times and he fails to answer let alone comply? Did the builder or the builder's plumber install it? Ozgarden Page 8: Wet system: insect and fauna proofing each inlet Each inlet AND outlet. The overflow pipe can however be fitted with an air gap (I believe that they are compulsory in QLD in any case) which is also best practice. The air gap's mosquito proof mesh substitutes for the tank's overflow outlet's mesh. https://www.youtube.com/watch?v=FP4pUxapeMs&t=4s Ozgarden Page 9: for a tank that is supplied by a wet system, a screened rainhead is installed for each downpipe that supplies the tank to prevent leaves and debris from entering the tank. This should be compulsory for every State as it is in QLD and most if not all other northern regions. 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: Water tanks and building codes 3Apr 13, 2021 8:12 pm The water tank is for the garden and wasn't plumbed in to the house so I didn't think the certificate of inspection would cover it. Should it if the gutter is connected to the tank? We later found out the builder owns the certification company and the certifier's the builder's employee. The final inspection didn't happen until after we moved in, and I walked around with the inspector. It took less than 10 minutes and it seemed as if the inspector was looking at the house for the first time. He basically glanced in each room and his only comment was about our polished concrete floor being the best the builder had done. Re: Water tanks and building codes 4Apr 13, 2021 8:26 pm While reading about water tanks and overflowing gutters...... I just noticed this figure in a Victorian government publication on charged systems. I live in Qld. Is there a reason why there is a 100mm height difference between the inlet and outlet? Our inlet and overflow pipes are at the same height on the top edges of the tank. Also, is there a requirement for inspection openings for cleaning on the underground closed system pipe? Ours doesn't have any. We also don't have rainheads on the downpipes for the closed system to the tank, or screens installed on the inlet and overflow pipes. Thank goodness there aren't as they are attached and it would all have to be pulled apart to clean any screen. I put some gutter guard in to try to stop all the leaves being washed from the closed system gutter into the tank every time it rains. To clean the underground pipe from the gutter to the tank we'd actually have to dig the pipes up and replace them probably. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Water tanks and building codes 5Apr 13, 2021 8:52 pm I was wondering if anyone can give advice about overflowing gutters. I've been trying to get the builder to do something about our gutters since we moved in but he says he'll come and look, doesn't, or makes excuses. Our back gutter is the worst. It is a charged (closed) system to a tank he installed. Three times he had to repair the underground stormwater pipe to the tank in the first year because they kept leaking. One time a join fell apart in their hands and obviously hadn't been glued at all during the original installation. At the time he said it was our fault because we decided after he'd put the pipes in to add a tank and that put extra pressure on pipes that weren't designed to hold it, 'there's pressure, and then there's pressure.' The first two times the builder and his apprentices cut apart the joins and repaired them with rubber boots to cover the gaps, with stainless steel straps at each end. The third time the plumber came and said one problem was a pipe being installed 'back to front.' Apparently it was all caused originally by the builder's bobcat running over the area and squashing the pipe a bit, causing the joins to leak. The back gutter is a closed system to the water tank. We had to install a gutter guard after realising there was nothing preventing everything in the gutter being washed into the tank, no mesh anywhere on inlets or outlets. The plumber said there isn't enough 'head' to install a rainhead. I asked him when he was here another time to repair the inlet and overflow pipes on the tank as they'd popped out, only being held in with a bit of silicon. Anyway, after all our gutters were overflowing yet again last week we wrote again to the builder and got this answer back. "If the water tank is full, the water in the gutters will have no where to go as the downpipes will be full and so they will overflow. If you’ve not tried emptying the tank when it rains, maybe try that?" We replied: "This is only the second time the water tank has been full since we’ve been here. The gutters overflow every time it rains and have done since we got here. We've been taking photos of it happening each time since April 2019. Also, the tank has a big overflow pipe the same size as the inlet pipe and as well as that, when it is full, water comes out of the unused inlet on top so nothing stops the water flow from the downpipes going into it. The builder told us, and your plumber confirmed, that only the back gutter is connected to the tank. As you could see in the photos we sent the front gutter and gutter over the garage at the front also overflows every time it rains and they aren’t connected to the tank at all." Last week was the first time we had heavy rain after the tank filled and to our dismay after hearing a sound like a freight train coming through our lounge wall we discovered the water was running out of the unused inlet on the top of the tank via a notch and hitting our wall next to the power point. We're not sure how we can remedy that short of emptying the tank and turning it a bit. This photo is after it stopped raining and I went out to see what the loud noise had been. The water was flowing out of the notch on the side of the unused inlet on top of the tank and hitting our wall. I know these powerpoints are supposed to be water resistant but it is a bit of a worry. The photo was taken when the water was down to a trickle. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ We had a plumber look at the roof and he said the roof has such a slight slope the runoff is probably hitting the top outside edge of the gutter and going over the top. He also said the gutters are the minimum size required and the cheap plastic brackets are letting the gutters sag. The plumber was here to fix a burst pipe in an interior wall of the house that caused a bit of flooding. It was actually a join in the main pipe supplying water to the bathroom. That happened 14 months after we moved in. We are still waiting for the builder to repair the big hole in the wall 10 months later. It is at the back of the inbuilt cupboard, but still!!! The builder's plumber assured us he'd done a pressure test and it had never happened to him before. With our other plumbing issues it isn't reassuring. Sagging gutter. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Water tanks and building codes 6Apr 13, 2021 9:40 pm Ozgarden The water tank is for the garden and wasn't plumbed in to the house so I didn't think the certificate of inspection would cover it. Should it if the gutter is connected to the tank? You need to check the QLD plumbing regulations but here in Victoria a COC is issued for plumbing work when the total value of the labour PLUS parts and fittings is $750 or higher. The water tank is also part of the stormwater system and is covered by many of the same regulations. Ozgarden We later found out the builder owns the certification company and the certifier's the builder's employee. The final inspection didn't happen until after we moved in, and I walked around with the inspector. It took less than 10 minutes and it seemed as if the inspector was looking at the house for the first time. I have been to your profile and found that I have answered your queries in the past. I remember the discussion about the certifier. Just unbelievable what has been allowed to go on in QLD. 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: Water tanks and building codes 7Apr 13, 2021 9:43 pm Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ I looked at the house on Qld Globe and did a rough estimate of the roof size. I think the nearest place for estimating the 1 in 20 rain event is Bundaberg. The section of roof on the bottom of the photo is attached to the tank via the closed system. The front rainwater pipe connects with the overflow from the tank and goes to a gravel pit in the front corner. This was dug in deep compacted clay and seems to constantly retain water, so I don't have to dig down too far to find it at any time of the year. I've left the cover off the overflow into the pit after it blew off in heavy rain a couple of months ago. I took this photo of our new fountain just before the concrete cover with the plastic grate blew off. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Water tanks and building codes 8Apr 13, 2021 9:51 pm SaveH2O Ozgarden The water tank is for the garden and wasn't plumbed in to the house so I didn't think the certificate of inspection would cover it. Should it if the gutter is connected to the tank? You need to check the QLD plumbing regulations but here in Victoria a COC is issued for plumbing work when the total value of the labour PLUS parts and fittings is $750 or higher. The water tank is also part of the stormwater system and is covered by many of the same regulations. Ozgarden We later found out the builder owns the certification company and the certifier's the builder's employee. The final inspection didn't happen until after we moved in, and I walked around with the inspector. It took less than 10 minutes and it seemed as if the inspector was looking at the house for the first time. I have been to your profile and found that I have answered your queries in the past. I remember the discussion about the certifier. Just unbelievable what has been allowed to go on in QLD. Yes. We had major issues with water around the yard. I don't remember actually posting anything about the gutters and tank before though. After all the flooding around the time we moved in we've mostly been in drought so at first the overflowing gutter problem hadn't been obvious. The first time it happened locals said it does when it rains heavily. But then we noticed ours overflowed and none of the neighbours did. We've actually solved all of the water issues in the yard except for what happens from the gutters overflowing every time it rains. Most of the water in the yard was actually flowing in from neighbours so raised beds around the perimeter fixed that. There was one large lake that 20 cubic metres of fill fixed. The raised beds took about 8 truckloads of soil. The gate into the yard is too small to fit our trailer through because it is off to the side of the driveway so you can't drive straight through. No truck can fit through. So we've narrowed a lot of tonnes of stuff into our yard. If our gutters actually worked we'd have no water issues in the yard now. Re: Water tanks and building codes 9Apr 13, 2021 10:53 pm Ozgarden I just noticed this figure in a Victorian government publication on charged systems. I live in Qld. Is there a reason why there is a 100mm height difference between the inlet and outlet? Our inlet and overflow pipes are at the same height on the top edges of the tank. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ There are many things wrong with the diagram and I will also address the answers to readers who are in other States The diagram indicates a wet system vertical riser discharging inside the tank (below the tank's roof) which is ok when a mosquito proof leaf diverter (aka rainhead) is fitted at the downpipe as shown in the diagram but maybe they mean to represent the pipe discharging into the tank's top meshed inlet which has mesh at the bottom althought the depth of the cavity is usually about 70mm. The pipe shouldn't sit on the mesh anyway. It is best practice to have a tank that provides some mitigation capacity during heavy rain events so maybe they mean to indicate this. The diagram isn't to scale but the 100mm gap indicates the height difference between the overflow pipe's invert and the bottom of the inflow pipe. This really makes no sense though because some inlet pipes discharge into a flooded 'calming elbow' located on the bottom of the tank. This is best practice. Just put it down to whoever drew the diagram and those who approved it not knowing their subject matter. Ozgarden Our inlet and overflow pipes are at the same height on the top edges of the tank. Hmmm! Do you mean at the top of the tank's side? Water must pass through mosquito proof mesh before entering the tank, do you have mosquito proof leaf diverters fitted to each wet system downpipe? Ozgarden Also, is there a requirement for inspection openings for cleaning on the underground closed system pipe? Ours doesn't have any. It is a Victorian Building Authority (VBA) diagram which some other States also use but in Victoria, Inspection Outlets are not mandatory nor are mosquito proof leaf diverters (as shown in the diagram) for that matter. You need to check with your State plumbing authority and also your local council for your own compliance. The IOs as shown are archaic because the sub surface 'sump' is not properly flushed. There will be some cleansing velocity generated by the first metre or so of standing water in the vertical riser and the downpipes but that is all. Thank goodness there aren't as they are attached and it would all have to be pulled apart to clean any screen. I would be shocked if you are not required to have mosquito proof rainheads. Unfortunately, I don't have the time to trawl through the myriad of QLD regulations but your State Plumbing regulatory body would be able to provide the answer along with the reference. So,,,no screens on the tank inlet and outlet??? That is a disgrace. The inlet needs to be easily removed in case the overflow mesh gums up plus provide access for desludging. [quote defaultattr=""] Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ [/quote] A few more mentions about the diagram. The 300mm gap requirement shown between the bottom of the pipe at the top of the vertical riser and the leaf diverter (rainhead) is wrong, wrong, wrong! The length of inflow pipe PLUS the equivalent pipe length of all pipe fittings that represents their minor friction losses must be calculated to determine the minimum head requirement. The overflow pipe must also be sized and/or configured to have a discharge capacity that exceeds the wet system's inflow capacity during a high intensity rain event. Whoever drew and those who approved the diagram don't appear to realise that a wet system pipe flows full of water whereas a horizontal discharge pipe is less efficient than a vertical pipe plus the pipe will also draw a free surface vortex even when the water level is well above the top of the pipe. It must also be remembered that the outlet pipe's mosquito proof mesh barrier presents an additional considerable flow restriction. 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: Water tanks and building codes 10Apr 13, 2021 11:21 pm SaveH2O Ozgarden Our inlet and overflow pipes are at the same height on the top edges of the tank. Hmmm! Do you mean at the top of the tank's side? Water must pass through mosquito proof mesh before entering the tank, do you have mosquito proof leaf diverters fitted to each wet system downpipe? Yes, at the top of the sides. No mesh over the inlet or overflow. No mosquito proof leaf diverters on the wet system downpipes. Whatever lands in the gutter will flow into the tank. I tooked into the gutter today and the overflowing section had 5mm deep green wet slime in it. Perhaps a low spot? The entire length doesn't seem to be washed out very well when it rains. The inlet needs to be easily removed in case the overflow mesh gums up plus provide access for desludging. There is still the manhole inlet on the top of the tank that isn't being used. The builder put the inlet into the side at the top and the same sized outlet at the same height on the other side of the tank. It must also be remembered that the outlet pipe's mosquito proof mesh barrier presents an additional considerable flow restriction. No barrier on ours. Re: Water tanks and building codes 11Apr 13, 2021 11:39 pm Do you know the gutter size and are there overflow slots in the front wall? I need to know the gutter's cross sectional area to check compliance. How old would the gutters be (need to refer back to old regs). 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: Water tanks and building codes 12Apr 14, 2021 12:11 am SaveH2O Do you know the gutter size and are there overflow slots in the front wall? I need to know the gutter's cross sectional area to check compliance. How old would the gutters be (need to refer back to old regs). Slimline quad gutter with slots. 2 years old. I'm sure the gutter is 125mm wide.This photo might help estimate the height. A lot less high than wide it seems. I can get up and actually measure it tomorrow. Forgive the mould. I've actually washed the gutter twice since we moved in and took a photo to show all the mould that has grown since all the rain recently. This is actually on the north facing side of the house. The base of the gutter should be perpendicular to the fascia shouldn't it? Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ I've been wondering why a lot of water overflows the fascia on the left side of the above photo. Today I found out. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ The water from two corrugations on the roof flow directly onto flashing and that is sloped off the side of the roof. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Water tanks and building codes 13Apr 14, 2021 11:52 am https://cdn.dcs.lysaght.com/download/quad-115-hi-front-xl-slotted-gutter-technical-guide Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ I am sure it is this gutter. 115mm wide. I tried to measure how far up the slots are and it is about 55mm. The downpipes are painted so using a tape measure I estimated they are 90mm external diameter. The pipe they go into and is part of the riser to the tank is 110mm external diameter. The three downpipes across the house are all 90mm too. The overflow from the tank and the three front downpipes must all go into a 110mm diameter pipe as I measured the diameter of the pipe coming up in the drainage pit where all the water ends up. I also realised the pipes going into and out of the tank might create a bottleneck. This is the inlet from the closed system pipe from the back gutter. They reduced the 110 to 90 towards the top of the riser. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Overflow Originally the elbow at the top of both of these was just held in place with silicon and only protruded a cm into the tank. When the tank did finally fill it popped both pipes out. So the plumber came back and was only going to resilicon over the top of the old stuff and stick them back in. I suggested he do something better. I asked about screens for the inlet and overflow but I just get ignored each time I ask such questions. There are none anywhere. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Water tanks and building codes 14Apr 14, 2021 11:50 pm I"ll address your concerns as a segmented block answer and also try to explain and reference the regulations so that you understand them. I cannot however help addressing the answer below that you received from the builder! Ozgarden Anyway, after all our gutters were overflowing yet again last week we wrote again to the builder and got this answer back. "If the water tank is full, the water in the gutters will have no where to go as the downpipes will be full and so they will overflow. If you’ve not tried emptying the tank when it rains, maybe try that?" Doesn't the builder know that water tank has an overflow fitted that is required to handle this situation? This goes on the list of the most ridiculous things that I have heard. HOUSE ROOF AREA: Total roof area: 278.3 sq m. 3 downpipes service the front roof area of 148.5 sq m. 2 downpipes service the back roof area of 129.8 sq m. These downpipes divert to the tank via a wet system. IF the downpipes each drained equal roof harvest areas, each downpipe would service 64.9 sq m. Roof drainage compliance factors the regions 1:20 Average Recurrence Interval (ARI) with the roof catchment areas drained to each downpipe to arrive at the gutter and downpipe size. The rainfall intensity is based on a 5 minute minimum average which is then referred to as an hourly figure but it is the 5 minute average duration that is noted. NOTE: The National Construction Code comprises the Building Code of Australia (BCA) Volumes one and 2 and the Plumbing Code of Australia which is Volume 3. The BCA, being the primary document, has hierarchy over referenced Deemed To Satisfy (DTS) Australian Standards AS/NZS 3500.3 Plumbing and drainage Stormwater drainage. I mention this because the BCA stormwater regulations are laxer than the AS, so much so that Victoria where I am based has never recognised the BCA for stormwater regulations. The BCA does however at times defer to AS/NZS 3500.3. Your stormwater regulations are based on the BCA Volume 2 regs found at 3.5.3 Gutters and downpipes. If you want a digital copy of the BCA Volume 2, just PM me your Email and I will send it. BUNDABERG 1:20 ARI: 265 mm/hr as per BCA Volume 2 3.5.3.1d This is a 5 minute minimum average duration of 4.4 mm/min. By comparison, the Bundaberg AS 1:20 ARI looks to be 310 mm/hr or 5.2 mm/min. Roof areas are also factored with a slope multiplier to account for wind driven rain but I won't do this due to the minor slope. The minimum average rainfall (BCA) over a 5 minute 1:20 ARI duration on the house roof is 278.3 (sq m) x 4.4 (mm/min) = 1,224.5 litres per minute (lpm). The minimum average rainfall (BCA) over a 5 minute 1:20 ARI duration on the back roof is 129.8 (sq m) x 4.4 (mm/min) = 571.1 litres per minute (lpm). This equates to a velocity through the 100mm DWV pipe of 1.12 metres per second (m/sec) which is well within its scope. WATER TANK FACTS: All water tank openings must be mosquito proof meshed. Mosquito proof mesh has apertures less than 1,000 microns (1 mm). You are required to have mosquito proof leaf diverters (aka rain heads) fitted to the top of each wet system downpipe. None are fitted. These regulations should also be found under QLD Health regulations. You are also required to have first flush diverters fitted. None are fitted. The wet system reduces from a 110mm Outside Diameter (OD) DWV pipe to a 90mm OD stormwater pipe so that it fits the 90mm inlet. The respective Internal Diameters of the two pipes are 104mm and 86.2mm, the DWV having 46% more volume. Water will flow through the 90mm wet system inlet with a minimum average velocity of 1.65 m/sec which is not good but it doesn't breach compliance. TANK OVERFLOW PIPE: The tank overflow pipe cannot be sized to apply a flow restriction and a horizontal outlet is much less efficient than a standing vertical pipe. Let's say you had a 100mm horizontal overflow outlet, the flow rate with 100mm of water above the pipe's invert (the bottom of the pipe) would be 280 lpm which is a lot less than the 571 lpm inflow during a minimum 1:20 ARI. With water 125mm and 150mm above the invert, the flow rates would be 343 and 396 lpm...or would they??? You see, those are figures for an unmeshed outlet whereas your outlet is required to be meshed! You should see now why the 90mm outlet, even without mesh, is totally inadequate. There are ways to increase the efficiency of an overflow pipe, I can post that information later. WET SYSTEM: The pipe run is about 30 m + the pipe fittings and flow restriction at the tank inlet which are expressed as equivalent additional pipe lengths. This would easily make the pipe length equivalent to +50 metres and the greater the velocity, the greater the friction loss. Such systems need competent hydraulic calculations and it is very, very obvious that this wasn't done. ROOF DRAINAGE SYSTEM: The BCA Volume 2 roof drainage calculations that determine your minimum gutter and downpipe sizes start at Table 3.5.3.2a GUTTERS: I will not paste the NCC (BCA) charts due to copyright but if the two downpipe servicing the back roof area were draining roughly equal roof catchment areas, we would consult the left hand column with an ARI of <275 mm/hr. The prior column is 255 mm/hr and so your 265 mm/hr defers to 275 mm/hr. We then move along the top column to a roof catchment area of <70 sq m and it states that a type F size gutter is required. You will also note that for your 1:20 ARI, a type F gutter is required for a 1:20 ARI of 200 mm/hr or greater and so your gutter size needed for compliance is well in excess of your standard gutter IN ALL AREAS of the house. Your gutters are probably 125mm quad, having 115mm quad is way, way beyond the realms of possibility even for these clowns. A Type F gutter is noted in the BCA as "Gutter must be designed in accordance with AS/NZS 3500.3". It will be a big gutter but there really should be more downpipes and certainly an extra one between the two downpipes at the back. This will require the gutter to also be resloped as the middle section will currently be the gutter's high point. You also need to find out the size of the pipe that joins the two 100mm DWV pipe runs and is plumbed to the LPOD. DOWNPIPES: Your description of ponding indicates that the gutters need resloping. The downpipes at the front are well positioned but it is possible that the gutter's mid point is also its low point, the gutter's slope needs to be checked. The overflow could however be caused by having a 100mm DWV pipe run all the way to the LPOD. As per the NCC Volume 2, the gutter and downpipe size is deferred to AS 3500.3 specs and the 90mm downpipes DO NOT cut it. As a quick, easy to plumb and inexpensive interim solution to the overflowing gutters, you could fit some of my Gutter Pumpers. You just need to know where you will drain them to but you may need a detention tank. https://www.gutterpumper.com.au/ The builder, plumber and certifier need to be reported to their respective regulatory bodies and a forensic investigation of your stormwater plumbing urgently requested. 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: Water tanks and building codes 15Apr 15, 2021 8:22 am Ozgarden Our back gutter is the worst. It is a charged (closed) system to a tank he installed. Three times he had to repair the underground stormwater pipe to the tank in the first year because they kept leaking. One time a join fell apart in their hands and obviously hadn't been glued at all during the original installation. At the time he said it was our fault because we decided after he'd put the pipes in to add a tank and that put extra pressure on pipes that weren't designed to hold it, 'there's pressure, and then there's pressure.' The first two times the builder and his apprentices cut apart the joins and repaired them with rubber boots to cover the gaps, with stainless steel straps at each end. The third time the plumber came and said one problem was a pipe being installed 'back to front.' Apparently it was all caused originally by the builder's bobcat running over the area and squashing the pipe a bit, causing the joins to leak. I couldn't make sense of this the first few times that I read it but I now suspect that he was possibly/probably referring to the pipe flowing with reverse slope along one section. If so and while this makes no difference to the hydraulic head, it will foster a build up of crud that will result is a further flow restriction. Having the pipe slopes checked is a particularly critical matter due to there being no leaf diverters fitted to the downpipes. 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: Water tanks and building codes 17Apr 15, 2021 10:48 am This is going up on my Wall Of Infamy. BTW, NCC Volume 2 3.5.3.5 states: "Downpipes must - (a) not serve more than 12 m of gutter length for each downpipe". 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: Water tanks and building codes 19Apr 15, 2021 11:06 am SaveH2O This is going up on my Wall Of Infamy. BTW, NCC Volume 2 3.5.3.5 states: "Downpipes must - (a) not serve more than 12 m of gutter length for each downpipe". I've seen that quoted all the time on other forums then people all argue about the interpretation of it. People say that can mean that if you have a 24m gutter you still only need a downpipe at each end so each only serves 12m. Re: Water tanks and building codes 20Apr 15, 2021 1:00 pm Ozgarden People say that can mean that if you have a 24m gutter you still only need a downpipe at each end so each only serves 12m. That is correct and it is something that I have posted many times to point out the absurdity of the reg. Suitably sloping such a gutter would result in a large height variance between the gutter's mid way high point and the low points at the downpipes. This in turn encourages fitting a minimal slope which then has slow water flow and an inadequate flushing capability. The 'brains' that be who are responsible for the poor BCA stormwater regs have also changed the wording several times. Prior to May 2007, the Building Code of Australia (BCA) stated: The spacing between downpipes must not be more than 12 m. This was revised on the 1st of May, 2007 to... “3.5.2.5 Downpipes - size and installation Downpipes must - (a) not serve more than 12m of gutter length for each downpipe; and (b) be located as close as possible to valley gutters and, if the downpipe is more than 1.2m from a valley, provision for overflow must be made to the gutter; and (c) be selected in accordance with the appropriate eaves gutter section as shown in Tables 3.5.2.2.” In effect, the above meant that two downpipes each serving 12 metres of gutter could be fitted at either end of a 24 metre long verandah, i.e., 24 metres apart. It also confused building surveyors and others because many thought that the gutter length served defined compliance, not adherence to the maximum allowable roof area drained. On May 1 2013, the BCA was amended to once again state "The spacing between downpipes must not be more than 12 m." And of course it has flopped again to the current regulation. Downpipes are invariably poorly positioned for aesthetics rather than function in any case yet still be compliant with the regs. This is why so many downpipes are fitted at the end of walls. There are also no (common sense) regulations requiring downpipes to be fitted to a section of lower storey gutter that an upper story downpipe discharges to via a tiny spreader. It is common to see an upper storey downpipe discharging a concentrated flow of water to the end of a gutter on a garage roof that has the downpipe fitted around the corner on the blind side. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Aesthetics subjugating function! And of course why not have NO downpipes at the front as part of the tidy up? Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. That was always going to be a challenge and a test of patience. Full marks to your mate. Did you discuss the wet area near the trampoline? 16 17375 I want to build a decking to the drawn shape outlined in black. The problem is how close can I build to the gas hot water unit? Will I be able to build around it and be… 0 20232 |