Browse Forums Paving & Concreting 1 Apr 04, 2009 2:34 pm Hello, I have a weird issue with my 30 year old slab wanted to know if anyone knows what the problem is and could recommend a specialist company that could fix it. Details are below: In two locations in the bedroom the concrete began to lift and crumble. My builder dug out the concrete and filled with some waterproof mixture followed by a levelling compound. He thought they cut a hole (unknown reason) and repaired with quick set mixture without repairing the moisture barrier. However, the lifting has begun and there is moisture on top. I have attached some photos. Any ideas would be greatly appreciated. Thanks Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Any one seen this slab problem before? 2Apr 07, 2009 11:16 pm Can you take a photo of adjacent outside and is this the south side? Where you are coming from is where you are going to... Re: Any one seen this slab problem before? 4Apr 09, 2009 11:29 am Hmmm... where does the downpipe go? to Storm water? Checked the down pipe and gutters for leaf litter detris blokage? Couple of things to think about. South side, so never in sun... always damp? Why does the gas meter have different colour concrete? Is it wet? Does the gutter leak at the joins above? It might not rain but there is always dew on the roof/gutters from the night before. The wall/fence in the first photo, does that retain soil? IE is the neighbours house above you in terms of ground height? Soz for 20 ???s onc Where you are coming from is where you are going to... Re: Any one seen this slab problem before? 5Apr 09, 2009 11:46 am Looking at the inside pic of the stain and efflorescence (A crystalline deposit of salts which leach from the concrete as soluble calcium hydroxides and within a short period of time will combine with the atmospheric carbon dioxide to form insoluble calcium carbonates, usually white in color, appearing on the surfaces of masonry) and can also look like fairyfloss on a wall. The drying of the slab has produce the efflorescence, how long ago did you lift the lino? Where you are coming from is where you are going to... Re: Any one seen this slab problem before? 6Apr 09, 2009 12:40 pm Down pipe working, gutters not blocked. This area does get some sun especially during this time of the year. Reason for the different colour is that it is bitumen due to a repair on the gas meter line. Not wet. Fence is not retaining but there is a pool cabana next to the fence. There doesnt seem to be excessive moisture in the soil. Very confused Re: Any one seen this slab problem before? 7Apr 09, 2009 12:50 pm Regarding the slab, it was repaired about 9 months ago when we notice a mini volcano developing under the carpet. My builder cleared the holes looking for a leaking pipe in the slab but just believed it was a bad repair. Unfortunately we noticed the lumps under the carpet over the last month or so I took the photo last week as it seems to be growing. Re: Any one seen this slab problem before? 8Apr 09, 2009 1:26 pm So it was repair 9 months ago say back in june. I wonder if a proper grout was used, or is it just cement. If you tap it does it sound hollow or drummy? You mention a volcano under the carpet.. was it chalky stuff? Where you are coming from is where you are going to... Re: Any one seen this slab problem before? 9Apr 19, 2009 11:16 am Not too sure about the grout. They used some expensive treatment that is supposed to seal the concrete and react with any water It doesnt sound hollow but I have the carpet back over it. Yes previously it was a bit chalky prior to the current repair. It just crumbled with a screw driver. Re: Any one seen this slab problem before? 10Apr 19, 2009 11:24 am Prolly some krystol or radcon7. Crap in my opinion! A bit like a bandaid, they really never work Where you are coming from is where you are going to... Re: Any one seen this slab problem before? 11Apr 23, 2009 2:27 pm So, any recommendations on how to fix? - thanks I had an old shower unit that broke on me and when I took it off, there were only 2 water pipes, instead of the normal 2 water pipes and a shower head pipe. S o I… 0 36878 Hey There. No problems re jumping in. My original question was "should I have waterproofed" the concrete slab before putting batons down. We have been told we should… 7 4313 2 5802 |