ToughButterCup Posted August 24, 2018 Share Posted August 24, 2018 Well, actually, I have been avoiding it. Doing a Big Time @Onoff. Procrastinating a treat. This needs to go in the green space next to it. I have the guidance on how to do it. Here There's a couple of things that are making me eat too much chocolate today. The empty weight is only 125 kg: an easy job for my digger - But will the arm have the reach? The hole only needs to be 2.25 meters deep - But the sides of the hole won't be vertical so will the arm have the reach (to dig out the middle of the hole)? Which all comes down to do I hire a 5 tonner ? (Mines 2.6 tonnes) Where's Ed Graves ( @Construction Channel ) when you need him? Link to comment Share on other sites More sharing options...
Declan52 Posted August 24, 2018 Share Posted August 24, 2018 Going by that link your hole is under 2m wide so your digger will be plenty able. Why would you not be digging the sides vertical??? Do you have a high water table as I know a local guy here put one of them in and it floated out of the ground. He had to dig it out and instead of pea gravel he used a dry mix concrete to hold in place. Link to comment Share on other sites More sharing options...
Onoff Posted August 24, 2018 Share Posted August 24, 2018 Digger? Pussy! Man up! Link to comment Share on other sites More sharing options...
newhome Posted August 24, 2018 Share Posted August 24, 2018 Know nowt about digging but wouldn’t you dig out the central hole first and then the shallower outer bit afterwards? Link to comment Share on other sites More sharing options...
Russell griffiths Posted August 24, 2018 Share Posted August 24, 2018 I have exactly the same dilemma although you digger is bigger than mine. The answer is to dig down 300/400 mm beside the hole to create a hole for the digger to sit in nice level base track the digger into the lower shelf sit there to complete the lowest dig. I have seen the level piling matt you made, I don’t know why your worried ??? crack on son. PLEASE BE CAUTIOUS OF ENTERING A HOLE WITH OUT ADEQUATELY SUPPORTING THE SIDES. Link to comment Share on other sites More sharing options...
ToughButterCup Posted August 24, 2018 Author Share Posted August 24, 2018 47 minutes ago, Russell griffiths said: [...] The answer is to dig down 300/400 mm beside the hole to create a hole for the digger to sit in nice level base track the digger into the lower shelf sit there to complete the lowest dig. I have seen the level piling matt you made, I don’t know why your worried ??? crack on son. [...] Yer a star Russel. Piling matt? Yeah, with a 16 tonner. Oh, bliss, sheer bliss - proportional controls, a full-on sound system, pedal track controls, steel tracks ? Why am I worried? Because the more experienced I get, the more cautious I get but the more ambitious I get. 1 hour ago, Declan52 said: [...] Do you have a high water table [...] Partly deliberately delayed 'til now because the water table will be as low as it ever gets this week, (I hope) Link to comment Share on other sites More sharing options...
Jeremy Harris Posted August 24, 2018 Share Posted August 24, 2018 Our guys dug a stepped hole for our conical tank. Looked easier to dig to me, plus it allowed them to pour concrete around the bottom to secure the tank in place (it's held down by those wedge-shaped projections at the bottom of the cone - they lock into the concrete ring poured around the base). Link to comment Share on other sites More sharing options...
Construction Channel Posted August 24, 2018 Share Posted August 24, 2018 As Russel said. If you need to go deeper than your reach dig a shallow hole next to it. Your digger should be fine lowering it in the hole just make sure your blade is on the hole side. Also make ale sure you fill it with water before you surround it with the pea gravel concrete mix. If you don’t and it decides to lift you will end up with a very expensive mess. 1 Link to comment Share on other sites More sharing options...
ToughButterCup Posted August 24, 2018 Author Share Posted August 24, 2018 2 minutes ago, JSHarris said: [...] plus it allowed them to pour concrete around the bottom to secure the tank in place [...] Need to think that through in detail..... There's a concrete-it-in kit you can get I think. The one thing that's sure is that the water table will rise. And for all the world the poo tank could have come straight out of the harbour master's stock of Starboard Markers couldn't it? It'll act just like a buoy if I don't get this right. 3 minutes ago, Construction Channel said: [...] just make sure your blade is on the hole side. Also make sure you fill it with water before you surround it with the pea gravel concrete mix. If you don’t and it decides to lift you will end up with a very expensive mess. Blade on the hole side? Wot, me, make a mistake like that? Well I did once; just the once. Oh, and I'll need a water bowser then wun oi? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted August 24, 2018 Share Posted August 24, 2018 1 minute ago, recoveringacademic said: Need to think that through in detail..... There's a concrete-it-in kit you can get I think. The one thing that's sure is that the water table will rise. And for all the world the poo tank could have come straight out of the harbour master's stock of Starboard Markers couldn't it? It'll act just like a buoy if I don't get this right. You don't need the ground anchor kit with that tank if using concrete. Those wedges around the base key into the concrete ring you pour around the base and hold it down. Our tank was pretty much exactly the same, and is set below the water table, so we anchored it down using concrete, as it looked a better bet that using their ground anchor kit, which was a galvanised angle cross plus some galvanised chains, IIRC. Concrete just seemed easier, as we had a mixer on site. One tip, if using concrete, then make a chute down the side of the hole, just dug out of the ground, so that it's easier to get the concrete right to the bottom with the water filled tank in place. Link to comment Share on other sites More sharing options...
ToughButterCup Posted August 24, 2018 Author Share Posted August 24, 2018 Right folks. Thanks. I'm looking forward to the job now. Time to grease my nipples (there's at least ten on my Kubo.... ) 1 Link to comment Share on other sites More sharing options...
MikeSharp01 Posted August 24, 2018 Share Posted August 24, 2018 Don't forget the rules on supporting the sides of excavations more than 1.5M (IIRC) you don't want it falling in especially if you are down the hole fettling the corners with a spade IE head down not watching the sides. Link to comment Share on other sites More sharing options...
ToughButterCup Posted August 24, 2018 Author Share Posted August 24, 2018 Good point @MikeSharp01: 2.5 meters would bury me standing up with some to spare. Link to comment Share on other sites More sharing options...
ProDave Posted August 24, 2018 Share Posted August 24, 2018 Your digger is about the same size if not larger than what I had, it will do the job no problem. I was almost at full reach down into the hole by the time I got deep enough but could easily have dug a little ledge for the digger to go down onto if I had needed to go deeper There wasn't much headroom to lift it so just a short bit of rope The ONE thing I would do differently if preparing to do it again, is get a HOOK to hang from the bucket. I think it took 3 tries of lowering it in, no it;s not deep enough, take it out and dig a bit more, and that was a right PITA having to undo shackles. A HOOK would have made it a lot easier. Link to comment Share on other sites More sharing options...
Stones Posted August 24, 2018 Share Posted August 24, 2018 The relevant entry from my blog regarding installation of our treatment plant. As Jeremy says, the lugs/wedges provide the anchor to concrete in (as we did). Link to comment Share on other sites More sharing options...
ProDave Posted August 24, 2018 Share Posted August 24, 2018 5 hours ago, Declan52 said: Why would you not be digging the sides vertical??? Do you have a high water table as I know a local guy here put one of them in and it floated out of the ground. He had to dig it out and instead of pea gravel he used a dry mix concrete to hold in place. I dug a tapered hole. Less likely for the sides to cave in, and less concrete to fill it. The plant is after all a cone shape so why dig a cylinder shape hole for it? In my case it was concreted in up to the ring around the bottom as the anchor to prevent it floating out. Link to comment Share on other sites More sharing options...
Triassic Posted August 24, 2018 Share Posted August 24, 2018 You don't necessarily need to concrete the tank into the hole, you can fill the tank with water as you backfill around it with selected backfill. The weight of the water in the tank keeps it down! Link to comment Share on other sites More sharing options...
Jeremy Harris Posted August 24, 2018 Share Posted August 24, 2018 On 24/08/2018 at 17:37, Triassic said: You dont necessarily need to concrete the tank into the hole, you can fill the tank with water as you backfill around it with selected backfill. The weight of the water in the tank keeps it down! What then happens if you have a high water table (as we do) and you get the sludge pump in to empty the tank after a couple of years? That's when the damned things float up, when they've been pumped out during the two or three yearly service, and then sit virtually empty for a few days until they refill. Link to comment Share on other sites More sharing options...
Russell griffiths Posted August 24, 2018 Share Posted August 24, 2018 This also happens with fibre glass swimming pools, never empty one completely. Link to comment Share on other sites More sharing options...
ProDave Posted August 24, 2018 Share Posted August 24, 2018 27 minutes ago, JSHarris said: What then happens if you have a high water table (as we do) and you get the sludge pump in to empty the tank after a couple of years? That's when the damned things float up, when they've been pumped out during the two or three yearly service, and then sit virtually empty for a few days until they refill. Right or wrong, I run a hose into ours to refill it as soon as the tanker has left. But this is at the old house, where it was wrongly put in pea gravel, and I only ever get it emptied during a long dry spell, like the one we had this early summer. Link to comment Share on other sites More sharing options...
Triassic Posted August 24, 2018 Share Posted August 24, 2018 2 hours ago, Triassic said: You done necessarily need to concrete the tank into the hole, you can fill the tank with water as you backfill around it with selected backfill. The weight of the water in the tank keeps it down! Some good points made about the need to concrete the tank in place. So to recap...... Concrete the tank in place if you have high groundwater. If you have low or no groundwater then you can simply backfill around the tank with selected backfill material. its good practice to fill the new tank with water as you start to backfill, it helps weight the tank down, even when using concrete as the backfill material. I’ve worked on s couple of jobs where the lads have been rushing at the end of a day, placed the concrete late in the afternoon, not added the water and left site, only to come back in the morning to find that heavy rain overnight has flooded the excavation and the tanks is sat there floating above the concrete Link to comment Share on other sites More sharing options...
Lesgrandepotato Posted August 24, 2018 Share Posted August 24, 2018 @recoveringacademic my digger man is about £16 an hour. Sure he’d be happy to use your kit. That’s probably only a days work. Is it worth your time to look at it? Link to comment Share on other sites More sharing options...
ToughButterCup Posted August 27, 2018 Author Share Posted August 27, 2018 Folks, quick question: how do you define a high water table? How high, relative to a 3 meter deep hole, is a high water table? Link to comment Share on other sites More sharing options...
PeterW Posted August 27, 2018 Share Posted August 27, 2018 More than half way up your hole ... Link to comment Share on other sites More sharing options...
Jeremy Harris Posted August 27, 2018 Share Posted August 27, 2018 4 minutes ago, recoveringacademic said: Folks, quick question: how do you define a high water table? How high, relative to a 3 meter deep hole, is a high water table? I'd say that if you dig a hole 3 metres deep and you get water flowing into it from the ground at this time of the year, then you need to consider that you may get enough water around the installed tank to float it out of the ground when it's just been emptied and there's been a period of heavy rain for a few weeks. In our case our hole filled to about 1/4 of it's depth overnight, in very hot, dry, weather, which was enough to cause me concern and choose to fill it with concrete. Link to comment Share on other sites More sharing options...
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