Browse Forums DIY, Home Maintenance & Repair 1 Jun 11, 2014 6:40 am Hi, The scenario is that we have a substantial established garden (mostly ornamental, edible upgrades planned) in the ACT, and to improve water re-use I've been considering how I could retrofit a greywater system. The property has a mild slope East-West, and being 60s (IIRC) brick veneer sub-floor access ranges from good (comfortable kneeling and I'm not short), to OK crawling/occasional belly slide at the East end. I'm wondering whether the effort and $ would be worth it given the below. The laundry should be easy as it is against a North wall and access is good, the bit that has me wondering is the ensuite and bathroom. Both are along the East wall and sub-floor access is not great. The real kicker is that all the drain pipes appear to be encased in a fair bit of concrete/cement formed from the ground to almost flush with the floor. I haven't crawled under that many houses so don't know how typical this is for the era. Demolishing the concrete will be a decidedly uncomfortable job given space constraints. Getting the greywater to the North wall should be OK either sub-floor if that's allowed, or out the East wall and trenched from there. I haven't gotten to the point of determining where the diversion back to the sewer pipe would go. I assume the generous application of $ would overcome this but at some point the retrofit isn't worth it. What are peoples' gut feel or experiences with a similar situation? I would attach photos but am o/s for some time without access to any. Regards DM Re: Sub-floor drain pipes encased in concrete... 2Jun 13, 2014 3:47 am Sounds like a lot of bother for grey water reuse. Have you read any literature on grey water reuse? The only grey water I would (and do) use is the final rinse from the washing machine. The Alternative Technology Association (ATA) link below also links to 6 other researched reports and articles. All are well worth reading. http://www.ata.org.au/ata-research/ata-greywater-trial Have you considered getting a water tank and locating it at a reasonably high area so that you can gravity feed to the garden via gravity fed drip hoses (not to be confused with standard drip hoses)? It needn't cost much to do; I could have bought a 1 YO never used 4,000 litre tank for $300 last week. 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: Sub-floor drain pipes encased in concrete... 3Jun 13, 2014 10:32 am As per what SaveH2O is saying. We looked into greywater re-use at our place but the $ involved means it is much more cost efficient to put in a bigger water tank. This is for a new build but to retro-fit it to an existing home would be so much more again. From what I found in my research the health factor is the main thing to consider. Designing a well thought out system, ongoing maintenance, environmental impact etc are all issues we felt were too much to pursue this further so we just upscaled our water tank from 15,000 litres to 20,000L. Stewie Re: Sub-floor drain pipes encased in concrete... 4Jun 14, 2014 2:53 am Thanks for the replies. Yes it does seem like too much cost and effort for the return, but I thought it worth asking in case someone had a way of side stepping the obstacles. I've been researching grey/rain water systems so feel I have a fair grasp of the issues involved in each; forums like this, ata.org.au, and whirlpool are great resources alongside lengthier articles/books. I always welcome more info so thanks for the links. For greywater I think I'll focus on a diversion setup from the laundry as it will be pretty straight forward, subject to the appropriate consideration of how it will be used in the garden etc. Re: rainwater yes I have plans there, though frustratingly to capture the lion's share of the roof I will probably have to wait for other planned modifications to the property. More thinking required there. I should be able to capture ~50m2 of roof pretty easily on the East side, which being uphill will work well with a drip line. I may be able to experiment with gravity feeding to toilet cisterns as they'll be pretty much on opposite sides of the wall. Regards DM Re: Sub-floor drain pipes encased in concrete... 5Jun 14, 2014 3:52 am dagdamor I should be able to capture ~50m2 of roof pretty easily on the East side, which being uphill will work well with a drip line. It is important to maximise your roof harvest area but standard systems need to either divert additional downpipes along walls (which can be ugly plus windows tend to get in the way) or else divert downpipes underground to a vertical riser (archaic and real bad news) at the side of the tank. There is also a problem with tanks overtopping when additional downpipes divert water during heavy rain that is in excess of the tank's overflow capacity. These problems are overcome by using new methods that don't divert downpipes or use vertical risers or overflow pipes. dagdamor I may be able to experiment with gravity feeding to toilet cisterns as they'll be pretty much on opposite sides of the wall. You can gravity feed to a cistern provided you have one metre of head and the cistern is fitted with the correct cistern valve and a very low pressure gravity fed seal. I use to gravity feed to my main toilet for about 8 months of the year. The reason I still don't is because I now also supply the HWS with rainwater and everything now goes through a pressure tank. Prior to that, I use to just turn the pump off to gravity feed when I had sufficient head pressure to activate the cistern seal. Most people don't realise that water still flows through a domestic pressure pump when it is turned off. To gravity feed to a cistern, you need to fit 2 Fluidmaster 400UK063 cistern valves. You refit the mains water supply line to one and you connect the other to a PEX pipe that runs from the pump or tank directly to the cistern. You will then have two isolation valves on the wall, these also qualify as manual mains water switching devices as required by the plumbing regulations when connecting a dual water supply to a cistern. See the diagram on page 11 in the ACT Govt doc linked below. http://www.actpla.act.gov.au/__data/*** ... _tanks.pdf You should also have a check valve to prevent back flow to the mains supply but it should be noted that you should not have both isolation valves open at the same time. The cistern valves also have air gaps that prevent cross contamination in any case. You also need to remove the plastic pig's tail flow restricter from the bottom of the valve's shank and replace the standard high pressure seal with the optional gravity fed (red) seal, part number 242LP071. http://www.haron.com.au/fluidmaster_products.html 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: Sub-floor drain pipes encased in concrete... 6Jun 14, 2014 4:37 am For the toilet cistern feed that is exactly the setup I was looking at (probably from reading your or someone elses posts around here/elsewhere). From memory tank location on the East side will be easy as it/they can go pretty much right under the existing downspout(s) with appropriate debris filters/supadiverters etc. so no need to run pipe everywhere. Capturing the rest of the roof is problematic at this stage due to a lack of suitable tank locations, so I'd either have to pump or go some sort of complicated wet system and I'm not really interested in those for reasons you and others have no doubt expounded on in various threads I've read Potential modifications to the property (i.e. moving a garage) may make it feasible to capture the rest of the roof area (~150m2) but that's down the track. Regards DM Re: Sub-floor drain pipes encased in concrete... 7Jun 14, 2014 9:23 am A local sparky bloke went and put his toilets on to gravity feed, and because he was on tank water he had a claimed saving of $200 year in electricity from not having his water pump operating as much as it once used to be. You'd need to work out your own savings versus costs of new tank, cost of moving the water to it, plus the cost of extra plumbing fittings and installation, versus the time it would take to gain those savings back. We are looking at doing something similar for our new home, but not straight away, although we will be making provisions to make it easier to install down the track. We can easily put a poly tank of a few thousand litres up the top of the hill, and gravity feed down the 4-5 metres drop from there. Owner Building at Jimboomba Woods in Logan City Qld. Blog : http://bandlnewhomebuild.blogspot.com H1 thread : viewtopic.php?f=38&t=68283 . Re: Sub-floor drain pipes encased in concrete... 8Jun 14, 2014 12:45 pm dagdamor From memory tank location on the East side will be easy as it/they can go pretty much right under the existing downspout(s) with appropriate debris filters/supadiverters etc. so no need to run pipe everywhere. Capturing the rest of the roof is problematic at this stage due to a lack of suitable tank locations, so I'd either have to pump or go some sort of complicated wet system and I'm not really interested in those for reasons you and others have no doubt expounded on in various threads I've read Hi DM, The Supadiverta allows the tank to be located anywhere (no need to have the tank next to the house) as the downpipes share a common infeed pipe. The shared smaller higher velocity pipe also allows you to have connection points anywhere along the pipe where you can occasionally or permanently connect poly pipes that supply gravity fed drip hoses to different areas. Connecting to the pipe is easier than connecting hoses directly to the tank, especially if you need to water the opposite side of the house. Connecting to the toilet will give greater utilisation of the harvested resource. If you decide to get a pump, you will only need to operate it if you have insufficient head but my cistern infeed also operated with the pump's pressure whenever the pump was turned on to supply the washing machine or for other uses. A 1 metre head is recommended but I found that as little as 700 mm head would allow the cistern valve seal to shut off supply once the cistern filled. The flow is slower though. Having the tank fairly close to the cistern is a strong influence. Because cisterns only need to fill at 6 litres per minute (LPM), you only need a small pump. It isn't good to have a pump pushing against what is effectively an obstruction, this is why big pumps connected to cisterns have disproportionate energy use for the work performed. In many situations, you will see a tank with very little negative head or else positive head supplying a cistern yet an unnecessarily large pump is used! There is no need! If you also have a small pump supply a garden tap, just use large diameter pipe between the pump and the tap as well as using an 18 mm garden hose with an attached short length of 12 mm garden hose at the end so that you can use the standard 12 mm hose fittings. At 20 lpm, the 18 mm hose has approximately 8 times less friction loss. Friction losses = reduced dynamic head. The Victorian Building Authority (VBA) document linked below also has a diagram of the twin cistern valve dual water supply system that has a little more text detail than the ACT Govt link in the last post. Note that it is stated that the air gap substitutes for a check valve but if a check valve can be easily fitted to the mains supply line, then I always do so as a matter of course. They don't cost much. The twin cistern valve system is a lot neater and cheaper than using a mains water switching device. http://www.pic.vic.gov.au/__data/assets ... sterns.pdf 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Grab a hose, insert it at the top of the inlet/down pipe and turn the water on and see where the water is escaping from. Then you'll know. 3 8465 As most others have posted above the install isn't compliant. The pipe is meant to be covered in loose soil or sand, the pipe has holes in it that leaks out a termicide… 10 5727 Building Standards; Getting It Right! 1. optional, you can but normally just use the earth from the main switch board 2. should be enough but the distance determines voltage drop - sparky should work it… 1 28813 |