Browse Forums Building A New House Re: Does bored piers stops slab heave? 10Aug 14, 2018 10:37 am Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: Does bored piers stops slab heave? 12Aug 15, 2018 12:24 am Only just this week on my daily walk I saw a new house being built in an area that has had only a few days of rain in the last four months. They had laid a standard waffle slab, going within half a metre of the boundary. The plumbers had dug vertically down right at the very edge of the slab to lay the drainage lines and then re-filled the trench with un-compacted clay. I realise that when you are building to the boundary you don't get the luxury of maintaining a 45 degree angle of repose but even so, this slab was laid on bone dry soil and then a drainage trench dug right around the immediate perimeter and then only with the original soil tossed back in. OK, so I am not a builder and have no qualifications, but if this was my house I'd be quite concerned about all of that. With the home I am building I got into a dialogue very early about this whole heave / drainage /soil condition business. The builder I went with will actually deliberately introduce moisture to dry soil and won't go building over soil that is 100% dry. They told me they did this for two reasons - one is that it is much easier to compact the soil down versus when it is 100% dry and the second is to limit further soil expansion once the home is fuly completed and the paths built. As soon as the formwork is off the slab they build up soil around it to make the correct grade. They get the frame up as soon as they possibly can (after 6 days) and then the roof, guttering and temporary downpipes within a week after that. I know that my building process was not under ideal conditions because as you pointed out, Australia has had drought conditions more or less everywhere over the last year. Every new house I see going up near where I live (which is about 700 kms from where I am actually building) is having it's waffle slab poured on absolutely bone dry soil. And I haven't seen one single temporary downpipe anywhere. I suppose they feel they can get away with this given the drought but my own builder is finicky about all of this and wants them on straight away regardless. Re: Does bored piers stops slab heave? 13Aug 15, 2018 12:31 am building-expert The whole point about building on highly reactive soils is to stabilise and keep moisture content even. That is why special care is required during construction and good maintenance after. Regardless, any dwelling on a reactive soil will be at risk of an "event" (leaking drains, overflowing gutters as Save H2O talks about, burst water hoses, forgetting to turn external tap off, site flash flooding etc etc) Add to that poorly maintained neighbouring swimming pools and tree planting without understanding the possible ramifications. Hi there everyone i was hoping to get some details and some clarification on some potential defects that may have occurred our recent bathroom renovation. 1. There seems… 0 6975 How good is Simeon?! Always taking time to help others out! Wish we were building in NSW and could work together. Thanks for all that you do! 7 6588 DIY, Home Maintenance & Repair That’s very helpful information. Will find out more from there. Much appreciated. 11 13458 |