Browse Forums Building A New House 1 Dec 29, 2009 1:56 pm Slab down. We drove to our block yesterday and found next door sleeper retaining wall collapsed and leaning on ours. Went back today and our wall has now collapsed with the weight of the other wall. As we were there the owners from the other block drove by and blamed us for not back filling our retainer. We couldn't back fill as it will right up to the soil (apart from the back section). Now, at the front of their block it was 200ml from the boundary and at the back of their block it was 400ml from the boundary. The 200ml went but the back stayed put. Ours was 300ml from the boundary line. When we looked yesterday his posts had been dug what appeared to us very in shallow holes. Can anyone advise us what to do? Our house is due to be build after we return from the holiday break. Re: Retaining wall collapsed due to the rain .... help 2Dec 29, 2009 8:35 pm Advice #1 - take plenty of photographs. Include a measuring tape if necessary so that dimensions are clear eg record evidence of "shallow" posts. Beyond this .... maybe other forumites can help. Chris Re: Retaining wall collapsed due to the rain .... help 4Dec 29, 2009 8:57 pm Wheres your block eg. which city / council? I am pretty sure standard building code practice is retaining walls cant be any closer than 1500mm to each other. Doesn't matter what height they are. Also doesn't matter if there is a boundary between you. If they are closer than 1500mm they should have council approval. That said alot of 'guys in the trade' recommend for every 1000mm up, the next wall is 1000mm away. So if your wall was 500mm high, it should be atleast 500mm from the neighbours. I dont condone this, but it is common Whose wall went up first, and what height are the walls? I hate to say it but chances are who ever built the first wall, would probably have the 'edge', as the person who built second should have been 1500mm away. Generally if a wall is under 1.0m in height most councils dont require an engineering/building certificate, unless -its within the 1500mm of another retain wall / a building / or is load bearing. If you build closer than this, then you bear the risk. Another General rule also is for every 100mm above the ground when building your wall, you go 100mm below. To be safe you should go at least 1200mm down if building a 1000mm high wall. Maybe try and see what the neighbour has done This is just some general info i have found from researching and talking to council / engineers. You may want to do your own, but i hope this helps a little Re: Retaining wall collapsed due to the rain .... help 5Dec 29, 2009 9:43 pm Trying to understand. It would be good if you get the chance to post some pics. I'm wondering if you excavated at all or was there a slope on your side that you intended to build up into a garden bed? Re: Retaining wall collapsed due to the rain .... help 6Dec 29, 2009 10:13 pm Thank guys, The neighbour went 600mm down to support 900mm retaining wall and this was on fill not into solid/natural ground. He has also built another retainer on another block and his other wall is leaning too, another downpour and we think this wall will be down too. Our wall supported his fallen retainer for at least 24hrs until ours collapsed with the weight. We did build our ourselves and at a max height of 800mm at the point of the collapse. Our sleepers were into natural ground. He paid for someone to build his retainer but we think they were poorly done ... we could move the upright concreted posts on his other block. Unfortunately, we built ours after theirs. His block is that soft I couldn't stand on it today, it isn't compacted at all, it's all fill. There are pictures on our blog of the retaining walls before they collapsed. Re: Retaining wall collapsed due to the rain .... help 7Dec 29, 2009 10:26 pm Who put the fill on his block, did he build it up to level his land? Did he discuss his intentions with you? Was there any discussion between you to coordinate the walls? Re: Retaining wall collapsed due to the rain .... help 8Dec 29, 2009 11:21 pm Macy Who put the fill on his block, did he build it up to level his land? Did he discuss his intentions with you? Was there any discussion between you to coordinate the walls? He put the fill on his block to build up the level of his land, cut one side and filled our side. He did not discuss his intentions with us. He has already fallen out with the two neighbours on his other block about retaining walls. He came to us today with accusations, kept telling us it was all our fault, we did not say anything about fault at this point because we needed to go away and discuss it. If they came with the intention of sorting it out without being confrontational then we would of tried to sort it out but we wasn't sure who was in the wrong so we kept our traps shut and let him rant. We need to sort this out and quickly or our builder wont continue the build. Just not sure what to do next. See blog. Re: Retaining wall collapsed due to the rain .... help 9Dec 29, 2009 11:59 pm His retaining wall. His fill. You haven't changed your ground level (yet) or undermined his structure, he built it up, I'm understanding that right? It seems to me that it should be his responsibility to make sure his retaining wall is constructed properly and is self-supporting or whatever the appropriate expression is, and not in a way that's dependent on subsequent action by anyone else. I have a nagging feeling I've read something somewhere about this, something about the structure needing to be self-supporting and not reliant on anything else, but it's after midnight and I'm really just not sure... Sorry you've got this situation at a time when you should be feeling excited. Re: Retaining wall collapsed due to the rain .... help 10Dec 30, 2009 6:12 am Ozzy it sounds like his wall was very poorly constructed. I feel sorry for you mate, this would be a nightmare. We had a few issues with our neighbour with building retaining walls, hence my above post. http://forum.homeone.com.au/viewtopic.php?f=19&t=26918, the worst would then to have one of the walls collapse Macy makes good points about who has altered 'natural ground level', some view it as the the more you alter, the more you are responsible for(i think this is in SA though) . Did he have drainage also behind his wall? Did you have drainage behind yours? With mine and my neighbour we used the same tradesman to do both our walls, he wouldnt do the upper wall until the bottom one was done and back filled accordingly At the end of the day i would assume you will both have to pay for your own walls, but i would be pushing for his replacement wall is built to a better standard, and again as per my above, try to build 1500mm away from his wall. If you cant then a min 900mm from his wall if he has built 900mm high (Although it doesnt 'comply') Just out of curiosity where is the boundary line? As FYI you cant build any one structure higher than 2.0m. So if your retain wall is 900mm and your fence is going on top of it the fence can only be 1.1m high. If you build the fence on seperate posts behnd the retain wall you can go to 2.0m "again above just given in good faith and suggest you still do your own research/investigations" Re: Retaining wall collapsed due to the rain .... help 11Dec 30, 2009 7:47 am Hi How close is his house being built to his retaining wall....this should have been an engineered retaining wall with approval from the council as it is above natural land levels. You should have also been advised of this as it would affect the way you erected your retaining wall. I would be a bit worried about his house sliding on to your house in a really bad storm if this is how his wall fails after heavy rain. You need to get the council out to have a look at this urgently. I wouldn't leave it a day. By the look of the pictures before the collapse his was on the lean before yours and the pressure of the wall and the extra soil would have pushed your wall over. Best of luck! Speak to your builder as well. Carolyn Re: Retaining wall collapsed due to the rain .... help 12Dec 30, 2009 11:38 am Well they are want to take us to court We got a builder to have a look and he said he could get it cleaned up today for us. Unfortunately, they won't let us on their land to do this. We are willing to clean up the mess (but not admit liability because we do not feel that we are liable) at a cost to ourselves. Then he rebuilds his and we rebuild ours, it seems the quickest and sensible solution so we can both get on with our builds in January. Sadly, they don't want to know. Re: Retaining wall collapsed due to the rain .... help 13Dec 30, 2009 11:52 am I would be talking to your SS and see if they can recommend someone that you can get in to examine it all. It looks like that they will just try to blame you, so if you get an inspector of some kind out to examine it all then that should help if you go to court or mediation etc 'A bottle of wine contains more philosophy than all the books in the world.' Louis Pasteur Vegie garden: viewtopic.php?f=19&t=27637&start=0 My Backyard Adventure Re: Retaining wall collapsed due to the rain .... help 14Dec 30, 2009 2:21 pm ozzybird Thank guys, The neighbour went 600mm down to support 900mm retaining wall and this was on fill not into solid/natural ground. He has also built another retainer on another block and his other wall is leaning too, another downpour and we think this wall will be down too. Our wall supported his fallen retainer for at least 24hrs until ours collapsed with the weight. We did build our ourselves and at a max height of 800mm at the point of the collapse. Our sleepers were into natural ground. He paid for someone to build his retainer but we think they were poorly done ... we could move the upright concreted posts on his other block. Unfortunately, we built ours after theirs. His block is that soft I couldn't stand on it today, it isn't compacted at all, it's all fill. There are pictures on our blog of the retaining walls before they collapsed. Hi Ozzybird Unfortunately they were simply to close to each other looking at the photo's. they should be the same distance away at a minimum than the tallest one and to be safe 1/5 deeper than the actual height above ground eg if 800mm above ground I would go 1m deep. I would have built them at least a metre+ apart in your case and I think you may be the one liable given you built so close and second as he holds the line. Not sure council would have approved this due to 1.5m guideline and type of material used. Hope it all works out amicalbly. Cheers Re: Retaining wall collapsed due to the rain .... help 15Dec 30, 2009 3:24 pm Hey Ozzy, What a terrible situation you've found yourselves in. I can't offer any advice, except perhaps to contact your council and Coral. It must be really stressful for you both. The neighbour sounds like a idiot and I hope you can get it all sorted out soon. Good luck and hopefully a Happy New Year Re: Retaining wall collapsed due to the rain .... help 16Dec 30, 2009 9:58 pm Every now and then, and I'm sure just about anyone will agree, the neighbour from hell turns up and it sounds like you have found one here. Not even the best pesticide known to man can deal with it. Cut of his head and another will grow back. I've met a few of these over the years in one of my previous professions and he/she or both are looking for someone else to pay for their problems which have been brought about by getting the cheapest quotes possible. When it fails, it's not their fault because they paid someone to do it so why should I pay again. Sorry to say this but there isn't going to be an easy solution, although I applaud both of you for keeping your mouths very tightly closed. Hope it all works out for the best soon. PD Hayman 34 H1 Thread https://forum.homeone.com.au/viewtopic.php?f=31&t=29460&start=0 Blog http://miazfolly.blogspot.com Tiles 25/3/09 Colors 6/4/09 Tender 7/5/09 Contract 28/5/09 Land 16/11/09 Re: Retaining wall collapsed due to the rain .... help 17Dec 30, 2009 11:11 pm ozzybird Unfortunately, we built ours after theirs. OK this is the bit that worries me. I've gone through your blog photos and reconstructed the sequence below because I don't want to flick between blog and here. Your block as you purchased it. Neighbours retaining wall is in place - understand that quality is questionable but undeniably the wall is standing retaining fill and I presume on the boundary. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Your builder (I presume) does a site scrape and this is the result... Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ What's been done is effectively removed any support the vertical supporting members of the existing retaining wall had has been taken away. Which can be seen in the photo below, there's two tenths of bugger all in front of the wall left. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ You (if I'm correct you've commissioned the wall not the builder) build another wall in front of the existing one. Being so close to the existing retainer (putting aside any general "rules-of-thumb" regarding distance between walls) your wall should have been designed to take the surcharge loading imposed by your neighbors wall. The principle is quite common in CBD's for instance - when they demolish an existing building and build a monster foundation which exposes the neighbouring buildings foundation the onus is on the person that dug the hole to protect the neighbours assets. Basically when you load a retaining wall (or apply a surcharge) the load is transferred as a horizontal load on the wall which is in addition to the "natural" earth load on the retaining wall. The further away that wall the surcharge load is the lesser the additional horizontal load, to the point where the surcharge load is so far away the wall does not feel it. That's why "rules-of-thumb" are pretty much irrelevant - they serve as a guide - but what were the original walls designed for? Basically you or your builder have changed the structural conditions upon which the neighbours wall was built. Now a couple of points on his wall - his wall may have been a *** design originally, it may have inadequate drainage or the drainage system failed to operate sufficiently during the storm and the hydrostatic pressure built up behind the wall), it may have been structurally weakened (e.g. I wouldn't have parked the excavator as close to the wall as what I can see in the first photo - again a large surcharge). However, this is pretty much all conjecture unless an obvious flaw is detected in the design. In any case your wall came second and altered the structural conditions - I'm afraid you're up for a rather difficult neogotiation/arbitration - and some fairly difficult issues to resolve on both sides. How people deal with the matter is an entirely different matter - it seems you're being reasonable and he's shooting from the hip - keep being reasonable because if you both rant then it will end up in an expensive sh!tfight. I'd suggest documenting everything, every discussion you have, every approval sought, document the design spec/instruction with your retaining wall company...as I think there is a case to seek recourse from your retaining wall builder/designer. Please correct any errors of fact in the above particularly on the sequence but in any case good luck... Cheers, Mike Edit: And apologies if it's not what you wanted to hear...but that's the way I see it from what has been presented. mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: Retaining wall collapsed due to the rain .... help 18Dec 31, 2009 12:12 am No eng' here but tdl is totally correct, also have seen this result on a few sites Where you are coming from is where you are going to... Re: Retaining wall collapsed due to the rain .... help 19Jan 06, 2010 9:51 pm Any update...? mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Thank you again Simeon.. I will call my certifier for that. Have a good day 4 5184 Thanks for your reply! All valid points and I agree with you on many of them. I am in QLD, any recommendations on a construction lawyer would be helpful 3 2637 Hi, does anyone have any experience with using Trex rain escape or EPDM rubber to waterproof a deck so you have dry space underneath. Popular in the US and realize that… 0 3443 |