saveasteading

Same with ours. 250kg slid off trailer ramp. Easy.

With diy or a helpful worker you can progressively surround with concrete/gravel/earth. A less sympathetic installation will end up with a lot of gravel and concrete used, and a pile of earth. Cheaper to avoid floating is bolting down or strapping down.

Not ' of course'. It isn't always necessary. The top coat must also be from the intumescent supplier.

Some do. Some are on gravel. If you are in a high water table area then it also needs to be held down. Mostly this is by concrete surround but tying down to a base slab is sometimes possible......I suggest you look at one or more technical details.

Ours did. Yes lovely and flat, and good for level too. For level control they put down some tiny tripods with a screw adjustable probe that gets lowered to finished screed level. They are spread around at about 3m intervals and the screed flows towards them . When getting up to level the hose man just points it somewhere else or edges forwards . I can't recall seeing them float it, as it was simply poured by skill and experience and it self levels. They just walk through the wet stuff if necessary, to lift the tripods out and it re-levels. The boss did all of that and 2 labourers not a lot, except unloading at the start and cleaning up at the end. They put in strips of mdf to form crack inducing gaps, pulling them out when the screed set enough. I didn't check the levels with a spirit level and straight edge, because it looked right at any reference points, and didn't cross my mind that there might be any issue, but the tiles went down without any suggestion of humps or hollows. Our only slight issue was that they had to pour it in a circuit, so got back to the start after about 3 hours, where the first lot was getting a bit stiff. No problem though. There is one crack where another control gap would have helped.

There is a 3rd way, which would be the cheapest but I haven't tested it. I discussed it with one of the concrete suppliers, who did not offer the proprietary screed mix. He said they offered a screed mix, made of normal sand and cement, but with small aggregate and a plasticiser. So it would apparently flow as well as Cemfloor etc but at normal concrete prices, which is about half, I think. We couldn't try it though because the specialist floor laying contractors weren't interested/ prepared to use it.

Thanks. Always happy to be corrected. I think you may have done well to find someone with the skill. No risk of floating the pir either. Was it an issue to get the dry mix to bed under the ufh pipes?

Its not a specially technical job. There is a right level to ensure for the inlet, make sure the unit is level, push in the inlet pipe. The exit pipe is then at the right level and you carry on to soakaway. Then there's a burp pipe and a cable. From talking to the jcb driver who lifted ours in, it was clear that he'd never seen anyone use a site level or spirit level on one, or a drainage field and he'd probably put in 30 he thought. Seems to me you need a groundworker that does what you tell them, because they don't know a lot. BTW the one we sacked didn't look at our designed gradients and went too steep then told me I was wrong. Grrr. Fortunately he only did a few m of rainwater pipe. That gets expensive if your entire run and tank is too deep.

Pir or eps or fancy fibre stuff. Then pb over it.

Yes about £30/ m2 for us too. Dry mix material for 60mm will only cost about £7/m2 delivered, but there follows shovelling, barrowing, spreading tamping and trowelling, perhaps into the night So Kelvin could have saved £3k with 3 fit person diy. Decisions? Pump mix obv. BTW, pump screed may crack, drymix won't, but it doesn't matter.

If you could get them to lift it into the hole, that would be a plus. The next one I do, subject to space and ground type, I may dig a ramp and manhandle it into place on gravel. That removes time pressure from the nagging digger driver ( who thinks getting it level is OTT. They only weigh about 250kg.

To buy yes it's much cheaper. To lay? No.

I'd leave the pb on, then add pir and a service void. As above, get it airtight, and the service void helps with that. Or there are insulating boards to put on the new inner face.

Liquid screed will take one day, but dry mix will take several. 50mm is fine if your insulation is level and the pipes aren't sticking up. The advantage of dry mix might be that it can be phased if you are tight for space, and diy if your back is up to it. I once saw a guy laying 800m2 of 100mm dry mix. Took 2 weeks for him and a barrower. Not my choice of job.

Phone the manufacturer as they know all the rules. Marsh will give you the price too, and your BM gets a commission out of that. Tell them the back story in case a particular klargester model has any significance. A sampling chamber is good practice too, whether or not planning or regs are asking for one. Normally I'd email thd planners to say I was using an alterative, but you don't need to here, as the BCI will approve it.

Klargester gets used generically, like hoover, so I wouldn't worry about it. Choose any equivalent, based on price and dimensions. Some need deeper holes. Some need concrete bases. Only consider air blowing ones. Diy is simple enough I think, but depends on your skills esp digging the hole and lifting the tank in. Ohh and level control, not that all groundworkers can get levels right. I have only ever used Marsh Industries. 3 times I think, and they are still my first choice. The first time was after much thpught, and the others because why change? They deliver it themselves and the driver can manhandle it off.

The hse statement is sensible enough. If you choose to lean them, then secure them, any way you like. Is the cable readily adjustable, while holding the board just tilted back for removal? Thats the likeliest time for the stack to move. Hey, maybe the manufacturers have got it right, supplying them horizontal..

Every column in the world is sitting on concrete. Yes, you lose heat that way so you accept that or insulate the steel. The only other option is to insulate the outer faces of the foundation. I don't.

Don't reinvent this. There are standard solutions, all lab tesred, but make sure to do it thoroughly and as specified. Pay particular attention to the perimeter as any gaps there will defeat the object. I recommend "resilient bar" as an easy addition to mineral wool. but again, make sure it is done as drawn.

I had never heard of these, or the need for them. Is it a genuine concern? Are they much used? Or just required in risk assessments and not used?

Yes. but inset it before completing the internal wall, and cap it as well, and its minimal. It's just that I've come across some very poorly fitted resin bolts in concrete, and brick is weaker (dust/ too smooth a surface/ too thick resin/ not deep enough /not mixed.properly/ glue absent due to pushing the bolt and not turning it.). 1. 24mm foundation bolts pulled out upon tightening the nuts. 2. a hoist fell over with a lorry on it.......neither installed by me or any of our people! Managing our own works I've found all the other issues in good time. BUT I do favour resin anchors IF properly supervised.

Yes. You get lots of shots at shaping it to suit.

Or more often as bike storage. I like the old fashioned nut and bolt method where its possible. Resin anchors are often fixed without care. Not in this case obv, but when left to other parties..

Under the walls is a good idea, but still fill them with flexible filler. 2 layers of mesh is unnecessary.

This got my interest. There's loads online. There is a mention of an 'agriculture mix'. It appears to be high cement content to resist urine. That will cost just a few £ more. Come back for info on laying and crack control.