Browse Forums Paving & Concreting 1 Jun 04, 2011 10:55 am When you are concreting around the house, usually there are lots of downpipes entering the ground, right up against the walls and the slab. What do you do where the pipes enter the ground? For example: Do you always just concrete all around the downpipes, or do you leave a square shape around the pipe entry and later cut a paver into shape and push it into the space that you left free of concrete? Or ... ? I am wondering what happens when the numerous joins in downpipes give up and you get a leaking downpipe that needs to be repaired but you no longer have proper access?? Has anyone left the immediate area around the pipes free of concrete? Does this make any sense? My signature is distracting people from my wise posts ... Re: Leaving downpipes clear of concrete 2Jun 04, 2011 3:53 pm I will start this with....I'm not a plumber anymore but....if you have 90mm s/w entering the ground and are concreting then at least have it wrapped in ableflex to allow for movement between the house and the slab, which is bridged by the s/w pipe. The ideal scenario is to replace the house/ground section with some storm flex and your worries should go away. Re: Leaving downpipes clear of concrete 3Jun 04, 2011 6:22 pm Thanks, evo . I'm not sure what is stormflex ... maybe this??: Now, it looks like my thoughts are not completely ... dismissable? I am finding that more and more downpipes leak, so the sight of concrete set hard right around a downpipe makes me shiver ... Now, "someone" will not like going and replacing all the various bits "just in case". So maybe I can still get around this problem (and the downpipes - literally) by installing a paver around each one ... I can just imagine what's going on under the house where all the pipes are taped so hard to the black plastic ... ermmm ... does that matter??! My signature is distracting people from my wise posts ... Re: Leaving downpipes clear of concrete 4Jun 04, 2011 8:31 pm Here's a picture of typical concreting around our downpipes (before the aggregate was exposed). An expansion joint foam was used around it (Ableflex or similar). I'm not overly concerned about having to gain access to the stormwater pipe under the path. In the rare event we needed to, it would be possible as path is not that wide, and just 100mm deep. Re: Leaving downpipes clear of concrete 5Jun 04, 2011 9:24 pm Stormflex is a flexible pvc piping, looks very similar to aggie pipe except it's not perferated...and is white. It can act as a flexible junction between the s/w attached to your house and underground piping. Re: Leaving downpipes clear of concrete 6Jun 05, 2011 8:43 am Wow, thanks so much Trinity, appreciate it! Your downpipes are different to ours! As you can see, ours have quite a few separate pieces/shapes of pipe wherever the pipe needs to make a bend, and then all those pieces are glued together and the whole lot is very rigid and I assume it's supposed to stay so, or otherwise the joins loosen up and we start getting leaks. I'm not sure how yours work because they obviously don't need to have such rigid "become one piece" joins . Tanks for clarifying that too, evo Hmmm ... and of course, I didn't think I'd need to ask the concretor what he normally does here My signature is distracting people from my wise posts ... Re: Leaving downpipes clear of concrete 7Jun 05, 2011 12:26 pm From a plumbing point of view, it's better to have a flexible area in the junction between your house and surrounding soils, ridgid is not always good. This might help explain http://www.menzelplastics.com.au/flexab ... -pipe.html ...and the third bullet point from the top of list, http://www.bsa.qld.gov.au/SiteCollectio ... ainage.pdf Re: Leaving downpipes clear of concrete 9Jul 13, 2011 7:33 pm For those who find this kind of info useful - I heard from a builder / building inspector that we should actually leave downpipes completely clear of concrete - the concretors should box around the pipes and not come near them. I inquired if wrapping them in Abelflex would be sufficient - the answer was No. Another thing has just caught my eye from that second doco ... last bullet point states "No bedding material around inground pipes" as one of common issues. Pitty I hadn't noticed that note earlier and even though I thought "something" was just not right , I wasn't sure, so I didn't say anything to Those who do this every day or Those who have been doing this for 20 years. These knowledgable experts laid pipes straight into grey and red clay with heaps of voids under the pipes and bumps to prop them up sporadically. Also: What is the min. cover for 90mm stormwater pipes (which are used for garden drainage only) when placing a concrete path over it? Is 30-50 mm enough from top of pipe to bottom of roadbase bed? My signature is distracting people from my wise posts ... Re: Leaving downpipes clear of concrete 10Aug 01, 2011 11:01 am Hi Lex, I've found your post very useful, as I'm planning on DIY concreting around the house. The same question pops up and thanks to you, there are answers to it already. By the way, my termite protection has not been fixed since my SS never showed up/called after handover. But I'm about 80% sure that it wouldn't work. (If you remember our discussion under another thread...) Re: Leaving downpipes clear of concrete 11Aug 01, 2011 1:41 pm Thanks for your comments, bobbie, I'm glad that you find this at least a bit useful ... I am still looking for some healthy discussion about this ... By some weird chance, I also just happened to talk to a plumber about these DPs ... his answer was similar to the builder's in that he says that if there are issues with DPs/stormwater, concrete will be in the way (obviously) and they'd need to clear away some concrete anyway - meaning that, unless we don't concrete around DPs and above the underground stormwater pipes at all (which is a bit silly), any other "boxing up" or "Abelflex-around" solution will still not be enough to save the concrete from cutting. I think . The plumber suggested 20mm Abelflex-type of isolation around all DP entrant points - simply to cater for any movement. If there's trouble, concrete would need to be cut out anyway. Which leads me to my latest idea ... create isloation joints with sufficient clearance and plenty of room to the DPs entrant points. In case of problems, only the "isolated" area of concrete needs to be taken up (and replaced later on). This is good IMO becuase the work should be simpler and there's no reo to cut. The bad point is that these "isolated" sections of concrete will move differently, so I may find one section lifting up, and the adjoining section sunken down ... Conclusion (so far): I guess there is no silver solution in this case ... Re. the termite thingy (and I'd have to refresh my memory for details), maybe chase the SS until he appears ... My signature is distracting people from my wise posts ... Devkop The good news it is super easy to fix. Just get your plumber to divert it to the other side of the window. But for those people who are wondering what the… 2 1687 To my understanding early saw cuts are to control shrinkage cracks, so doing them now would be pointless. Control joints may reduce ugly cracking during periods of soil… 3 9827 |