Browse Forums General Discussion Re: Building on a lot with fill, have retaining wall over 6f 2May 17, 2024 6:22 am johal I booked this lot 3 years ago and last year I settled it. But when I booked it I wasn't aware of this fill. It has a big retaining wall on the corner side, 800sqm lot, 38m long. I am worried about building the house now, as if it will create troubles for me or not. Builder has advised 40 screw piers or may be more, havent got the engineering for the construction yet. Got the soil test done, soil tests photo attached in the post saying more than 4m/5m fill. Builder said it will be alright. Even I am thinking about how the shed in the backyard will be built? Will that require screw piers as well? Is the house gonna be strong enough? Anyone has been on the same boat? What should I keep in mind while doing driveways, landscaping, concrete around the house or shed? Please give your views Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Johal No need to stress. Your builder is correct. With good structural engineering your home will be fine. We use piers on 100% of our builds even if they are founded on rock, so having piers is a good thing. I personally don't like screw piers but a lot of people love them, I just prefer concrete, but I am sure your builder and engineer are going to do a good job. Importantly, the fill is classified as controlled fill, which means it has been compacted and tested. If it said uncontrolled fill I would be worried. This is common on new subdivisions. There are many cities in the world where land has been reclaimed and there are skyscrapers built on that such as parts of New York where land was reclaimed from the Manhattan River. Another point I just thought of is that a significant portion of homes in Australia are built on fill ( granted not 4m) but a lot of sites are cut and filled to get a level pad or bench to build on, so engineers are very experienced in designing for this. So in conclusion, everything will be alright Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building on a lot with fill, have retaining wall over 6f 3Jun 07, 2024 1:21 pm Thanks heaps for replying and explaining in detail, I was pretty anxious about it. We have got the developer approvals and applied for the building permits already. I hope they finish it in time and I get to move in it by end of this year Re: Building on a lot with fill, have retaining wall over 6f 4Jun 07, 2024 8:01 pm Does look like you may have drainage issue with the retaining wall from the photo. Re: Building on a lot with fill, have retaining wall over 6f 5Jun 07, 2024 8:49 pm groundzero Does look like you may have drainage issue with the retaining wall from the photo. They said they have put a pipe near the wall for drainage. Otherwise, what should I do incase we get to see the drainage problem Re: Building on a lot with fill, have retaining wall over 6f 6Jun 07, 2024 8:49 pm Building on fill is fine, there doesn't look to be good compaction right up to the wall. Equipment won't get close enough as it risks damaging the wall and the equipment. Find out if there was compaction testing done within 1m of the wall, or see if your engineer can get one test done against the wall. That second pic looks like the water is infiltrating into the less compacted areas. As Simeon says though, with good engineering and construction practice, building on fill is perfectly fine. All the best Perth Re: Building on a lot with fill, have retaining wall over 6f 7Jun 07, 2024 9:08 pm johal groundzero Does look like you may have drainage issue with the retaining wall from the photo. They said they have put a pipe near the wall for drainage. Otherwise, what should I do incase we get to see the drainage problem Is it that wet each time you go to site or was that photo taken after a wet few days ? Re: Building on a lot with fill, have retaining wall over 6f 8Jun 09, 2024 5:22 am If level one compaction/certified, this is generally can be found on as it has been compacted as per Australian Standards. The soil report should state the certificate of compaction relied upon in classifying the fill as controlled. Having said that, from the bore logs it doesn’t look like the soil is even compacted. The bearing capacity of the fill is very low about 50kPa which is equivalent to 1 DCP in 100mm. I would question the geotechnical engineer on that. With screw piles, we normally use it as last resort in design when we can’t find good bearing for the soil for substantial depth. Although it should be treated, designed and guaranteed for the expected life of the building. Versaloc is a mortarless besser block system that still needs a properly engineered footing. If you just do a 400x200 footing it will fail in time. At 17m long you need it… 1 22624 Thank you again Simeon.. I will call my certifier for that. Have a good day 4 6955 Hello, We are about to build and the plans show a part of the exterior wall is being built on top of a limestone retaining wall. Does this mean the retaining wall will… 0 7461 |