Browse Forums General Discussion Re: Void under slab 4Mar 04, 2024 8:35 pm It may be the trench for the pipe under there that wasn't properly backfilled and compacted. How wide is the settlement area ? The builder will shake it off. Slabs are designed to span certain soft spots or settlement areas.Two things I would keep monitoring is that the area doesn't expand further and stays localised and that the pipe under the slab doesn't disconnect or start leaking. If the settlement slows down or stop then you could get some resin injection to lift the settled soil.Take some floor levels then you can always double check the slab is not being effected in the future. Re: Void under slab 5Mar 05, 2024 6:47 am groundzero It may be the trench for the pipe under there that wasn't properly backfilled and compacted. How wide is the settlement area ? The builder will shake it off. Slabs are designed to span certain soft spots or settlement areas.Two things I would keep monitoring is that the area doesn't expand further and stays localised and that the pipe under the slab doesn't disconnect or start leaking. If the settlement slows down or stop then you could get some resin injection to lift the settled soil.Take some floor levels then you can always double check the slab is not being effected in the future. To me, that's what it looks like: poor backfilling and/or compaction. The width is about 1000mm maybe. That conduit in the photo is for the NBN. The water is about 500mm over to the right and I didn't notice any subsidence that way. It seems to be localised mostly around the NBN conduit and just behind the fence/gate towards the electricity. I did my deck not long ago where I had to Chemset some anchors into the slab. That part of the slab had a nice 200mm edge to it (from the bottom of the brick, to the bottom of the slab). The bottom edge of the slab was straight. Compare that with where my void has appeared, the slab edge looks messy and the vapour barrier hardly extends beyond the slab. Not sure if that works? I was told the issue is the headspace clearance requirement on step 4. My builder is proposing shifting the beam 310mm towards the kitchen...I'm… 2 2861 4 5239 |