Browse Forums Paving & Concreting 1 May 18, 2014 10:16 pm G'day. First post here, and a sticky question for you all. I've got an old cast concrete water tank which is in the way of a proposed extension, and leaks a bit anyway. Replacement cost in poly is in the order of $6k, and knocking down the old tank would probably be another thousand. I hate wasting anything anyway, so I was trying to come up with a way to move the old tank, and I had an idea. What if I dug down around the tank (it goes down about 1000mm underground) and made parallel cuts around it close to the base, ~90mm apart. Cut and knock out the concrete in sections, cut the reo and bend it inwards, and wedge blocks of 2x4 or 4x4 in the gap so the top section stays in place. Get a crane in and lift the cut-away tank body using straps or padded chains threaded through the gap. Set down on prepared new site, on bricks or pavers so the reo isn't touching the plastic membrane, and pour a new base for it. Has anyone here tried anything like this? Do you reckon it would work? The tank is about 50 years old, and needs patching again anyway - I'm a bit worried it might just crack apart. If it did work, would it end up costing more than just replacing the thing? Expert opinions (and just about any opinion would be more expert than mine!) would be very welcome. The tank is about 4.1m external diameter and 3.5m deep. Using a figure of 2.4T/m^3 for reinforced concrete, without the base it should weigh about 10.5T, if my figures are right. Many thanks in advance, SW. Re: Concrete water tank - movable or not? 2May 18, 2014 11:51 pm These old tanks can be pulled or pushed with a bulldozer but being a meter underground means you'd need to dig a mighty trench (or a ramp upto ground level) to the new site. The best way I've found to repair them is to install a plastic liner. Re: Concrete water tank - movable or not? 3Jun 13, 2014 8:52 pm Thanks for the reply - and my apologies for not replying to it sooner. I'm surprised you can shift a tank that way! - I would've thought that the lateral stresses would be too much. Unfortunately the tank's right up against the house, so I couldn't push it straight out to where I want it - I'd have to push it sideways and do a U-ey. Like you said, that's a big trench to cut. It's something else to think about, anyway. Cheers, and thanks again. DIY, Home Maintenance & Repair But if it is a ground level open pit, then it is not a charged system. No surprises there. The pipes have obviously been altered and there would be a reason for this.… 3 31287 If you can calculate the reasonable charged head from let's say 100mm below the gutter to the top of where the vertical riser's horizontal discharge pipe will be, that… 11 17540 Building Standards; Getting It Right! Thank you for the generous offer. I need to get the plumber out to give me an explanation. As mentioned I haven't seen any rain water discharge from pipes 1& 3. It… 7 10835 |