Browse Forums General Discussion 1 Sep 11, 2017 4:23 pm Not sure if you can help, We are on tank water and some years ago one of the pipes under the slab broke, we ended up diverting the plumbing to another water tank so it didn't go under the slab. Anyways there has been a hollow sound under the slab for a while and a few tiles have popped. Today I lifted one of the tiles and the slab has approx a 5mm crack in the area where the pipe burst. We have home insurance with Allianz and I want to dot all the i's and cross the t's before we go down this path. I have read their policy and as usual it's open for interpretation. I have contacted some structural engineers to look at forensic testing. I then plan to take that information to a solicitor alone with my insurance PDS and have them take the fight on. There are a few cracks appearing in the ceiling and adjacent concrete and we are worried that the issues may worsen. With the hollow sounds under the slab it's pretty clear the busted pipe has washed away a fair amount of dirt and this has caused the slab to move/crack. Has anyone gone through this type of thing with an insurer before and have any advice regarding insurance or what else I should do from here. I am guessing this is going to be an expensive project. Would really appreciate any advice. Thanks Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Cracked slab help please 2Sep 11, 2017 7:35 pm Hi sunny74 Before you go spending lots of money, the width of the crack is the least width because the variations in are invariably attributable to surface non-uniformity. To me the crack seems to be closer to 1 mm and in Victoria this is normally not claimable... at least structurally. The noise (drummy) will probably be the best indicator as to the degree of erosion under the slab. What is unclear to me is the exact method of bedding the tiles to the slab. Re: Cracked slab help please 3Sep 11, 2017 7:58 pm Thanks for your response Leonardo, the widest part of the crack is close to 5 mm but remember I have only lifted one tile, god knows what's under the rest, Ill take a better picture of the crack tomorrow. Yes the drummy noise is a concern, its not just drummy on one side of the crack but also on the concrete outside leading me to think a lot of soil has been washed away. We are a split level house...the leak has also meant a lot of water must have just been sitting under the slab and unable to drain away...lo and behold I had a termite guy do an inspection last week and we also have termites in that area, I suspect a cracked slab and excess moisture have created perfect breeding ground. I pay nearly $1,000 a year for an exterra baiting system grrr. From what Im reading sounds like insurance wont come to the party, more than likely say its either wear and tear or natural ground movement...its going to have to be up to me to prove that the ground was washed away due to the broken pipe I guess. Anyway thanks again...I will await the engineers ( and their bill ) Re: Cracked slab help please 4Sep 12, 2017 8:40 am sunny74 Unfortunately, engineers reports generally come when it's too late and repair options will cost 5+ the original installation cost that's if it can be repaired at all->Worse case within 20-30 years pull it down. OT I can't stress (no pun intended) how important it is to collect data & photographs during your build, maintenance and structural periods Some say It could have been avoided with expensive.inspection monitoring? Interestingly Apple, Google & Microsoft is making a push on home automation...Google.."what is differential slab movement" as if that will solve your problem? Good news is Ansys announced last week real time simulations via apps for Building Information Modelling (BIM) Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Cracked slab help please 5Sep 12, 2017 12:29 pm How old is the house? 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Cracked slab help please 7Sep 12, 2017 8:37 pm sunny74 You may need concrete coring in that area to inspect what is going on subsurface.I have heard of the concrete coring done without water which would be the preferred way if possible. You will then need a soil test to confirm the conditions below the slab and measurement of any gap between the soil surface and the bottom of the slab. Another non destructive method would be ground penetrating radar using high frequency but will give you limited information regard the soil conditions. It is not always the case that the soil is washed away because where is it going to be washed away too, more soil.From my experience the water causes soil settlement and that creates the gap. Common solutions are repairing the pipe then using resin injection under your slab but you must be careful not to break the existing pipes again from the injection process. The hole drilled for the concrete coring investigation can be used also to do the resin injection there by reducing the disruption. What area are you in? Re: Cracked slab help please 8Sep 12, 2017 8:57 pm Hi insider Yes have done some more research and I think the core drilling and resin will be exactly what I need. The old pipe is now redundant so that won't matter. I live near Noosa in qld, we have extreme dry periods and wet periods and have read the resin is great for this as it supposedly expands and contracts. I had a builder friend come and have a look this arvo and he also mentioned the core drilling and also that one of the footings on the opposite corner of the house looks to have dropped so am up for a bit of work. May not require an engineer now hopefully though. Thanks so much for your response Plumbers 'can be' plumbers, made all the worse by self certification which the building surveyor invariably accepts as proof of compliance! The good thing is that you know know. 3 4859 DIY, Home Maintenance & Repair Hi there, I just recently received my new house from my builder. We handed the house to another company to deal with the… 0 8911 Thankyou so much 😀 I've decided on White on white for doors and trims, White on white 50% on ceiling and Mt buller for walls. Fingers crossed it will look OK 😀 2 7158 |