saveasteading

I think some presenters have something to sell, but they can't fill 10 minutes with the facts so exaggerate. The less they understand it the more they exagerate. It's as if those prescious but flighty heat particles were rushing through a piece of timber as if it was a big hole in the wall.

Yes it might be moderately simple but this is SE work. If we are to help further we need photos.

Whatever we build, it is a thermal bridge to greater or lesser degree. BH can sort this And carpentry skills will be of huge benefit to the final product even though the SAP doesn't acknowledge build quality.

I like the word 'just' there. Would it also creep into every corner under the floor and expand to put an upward pressure onto the floor, as in underpinning? But its certainly going to be easier than barrowing in the first 80% So that is a decent shout for the bulk fill.

Not something I'm familiar with.

A coal hole? It would probably be difficult to fill and compact after the first few feet.

He says you've failed but doesnt know why? He put the numbers in. It doesn't sound like an expert, just someone with a licence for a sap spreadsheet. I've come across one such. He wasnt interested in the reality and just wanted to enter conservative defaults. Your construction should pass but tell more. Insulation spec in floor and roof?

Simple can be elegant. The trouble is the method. Imported stone ( a lorryload) has to be placed in the basement and thoroughly compacted. Where would it be stored? That mean breaking out the floor. Would the stone all be barrowed in? Then a new floor. So that does have the advantage of simple support to your floor and added lateral stability. You would have to move out for a month minimum. Another easy solution might be to support the existing beam. A central prop means that the beam only gets 1/4 of the current bending. Or a masonry wall all the width, or a new beam. All needing foundations. Not quite as disruptive but still a month out of the house. Gut feeling £50k including fees and unknowns. Lawyers will take more than the Engineers. 25 leases, £2k each. PS. On second thoughts there will be redecorating, accommodation and likely more that we don't know about. For discussion say £100k = £4k each. Would they all contribute or some not be able to or want to?

@Nickfromwales it's a very big deal as liability extends to the whole block of flats. And might there be other basements? Who owns the basement/ void?

. It needs to be made clear that there will be no blame. Whoever is top of the pile is making the decision. Only that way does the designer bring up the 'crazy' idea from the back of their mind. Or the contractor says... if only we could do x, and the designer says there is a way but hadn't realised it was a practical issue.

Im thinking @zoothorn doesn't need to turn off the water as it is after the taps, before removing this part but it may be prudent? A spanner with a decent long lever?

I don't like the idea. An SE is the best bet. The steel has to be examined. Rust isn't always as bad as first impressions. But there are usually other options such as multiple small beams, additional supports or a wall underneath. It's going to be expensive. Some insurers reject on any excuse. All you can do when getting a quote is answer to the best of your knowledge, so reread what you told them then try again. You are all in this together. Have neighbours been below? Pictures would help.

Stop Press. I replied 'identical' but I was wrong. I've spent the afternoon comparing the Scottish and English reg's because I had a feeling that might be confusing me. The old fashioned way with a printout and a yellow marker. First appearances show the same rules, calculations and options, referring to the same document, and with shared drawings. BUT they are far from the same. I haven't checked out the implications of which is stricter yet but simply warning anybody who is involved at present.

That's interesting , especially for 'too slow'. It may be easier, cheaper and less disruptive to build a drainage mound if the topography allows, and it won't take so much space. Thus ground that has slow percolation may be beneficial.... which is plain silly. I think the documents need more nuance as well as awareness of reality. Does your pipe reach the top of the mound by gravity or do you need a pump? A pump built into a tank appears to cost an extra £500 or so. I've also had a look at digesters that remove a lot more of the chemical which appear to be the main concern. The figures are very impressive. Unfortunately it costs more but still does not allow the reduction of the dispersal area.

The pumped screed we have used is cementitious but has lots of additives so my opinion (no research) curl is not a thing. If using a cement and sand screed by old fashioned tamping and trowelling, the water content is very low so much the same applies. With structural quality concrete I've never seen curl either, in some hundreds of buildings. I guess the mesh or fibres help somewhat but again I've never heard of it being a thing. Anybody's other experiences would be be interesting. Can do no harm and may do a lot of good. Would you mind reporting back on how much condensation is there tomorrow?

Not necessary. I've been both. Sometimes in one camp or the other. Mostly doing both together Turn friction into bouncing off and it is very satisfying and productive. Good designers and good makers who can accept suggestions will flourish. If there is friction then it's not for long / only once.

It's a ramp. So either tamp then float smooth, or deliberately tamp with grooves down the slope. The latter looks rugged and is slip resistant, but gathers muck. But the former only looks imperfect when you are on your knees doing it, and nobody else will look.

Good point. That would indeed push half a day's stuff into the drain. I've looked at, smelt and let settle in a jar, the effluent from 4 installations. No strong colour, smell or settlement but presumably there is still chemical content. I don't think much sludge reaches chamber 3 and then that decomposes like the rest. I'll have a read about the Solido for interest.

@flanagaj it's just that some of us have done this for decades. It is never easy for us either because every job is different And because people are people. We may get a little cross when our advice is ignored. But hey, we could be wrong. Listen to the advice.whether you take it is up to you. No violence, but make big decisions to take advice or not. I sympathise, but never assume that building is easy, or that the man in the white van has expertise. And keep asking and listening.

@JohnMothats helpful thanks, and will be especially so if I find we have overcalculated the area. Your numbers are much smaller than ours, but that will he because your percolation is very fast. 8 times as fast percolation means one eighth as much area. In my opinion, there is no chance that your drainage runs more than 5m into the system before disappearing, and the rest is redundant. I don't want to build a needlessly huge trench.. that's bad design. That's not how i have spent my career. Always looking for better, more efficient solutions. You know when they work because everyone thinks it's obvious. Equally, I'm happy to be told of a reason why I'm mistaken. That's expertise. But for now I think it's a very conservative design set by bureaucrats who are not thinking it through. Identical. The current project is SE England. At the Steading, the digger driver said he had lifted in about 10 digesters and all went to a rubble soakaway. So either he was mistaken or the bco's were equally ignoring the rules. Rules that inspire contempt are bad rules.

Good luck and stay calm and smiley. with 20% you could just about throw away he ones that bother you most. I reckon it will go well.

Yes but it is not in the regulations. A reed bed is. From Google Earth I can see historic views showing that the land was once a commercial orchard. Thus I know that there will be fragmentation of the clay from the roots, which will long have rotted, and that there was drainage to the field in herringbone layout. I'd also expect the trees and apples to have depleted the phosphates from the ground (this latter is not my area of expertise though: it's a guess) . None of this will matter to the BCO.: I'm just expanding on the particulars.

Thanks for posting that. It's not easy to see, but I reckon they've done something like it but not as drawing, and also there probably shouldn't be a discontinuity. Yes, I've been the Contractor's Engineer and also the consultant's (acting for the client) on different big projects. In all of these the checking was very thorough by both. But I've no idea of the US (prob NY own rules) ways. perhaps the contractor and designer were the same ownership. Remember too that it is easy to see now, but during construction this is a birdcage of steel with no floors... No excuse but it would not be for the faint-hearted to check every detail in-situ.

I'm supposed to be an expert in this but am hoping for some genius or experience on reducing the vast area required by the regulations for soakaways after the sewage digester. Basically there will be a Marsh 10 person digester which removes about 95% of the nasties. However the regulations require the same amount of drainage field as if it was the 45% of a septic tank, less a paltry 20% because it is treated. I even gave some advice on this, on BH, recently, suggesting phasing the soakaway and perhaps leaving phase 2 until later.... perhaps much later, unless we can see that it is needed. This house will be kept in the family so we aren't a developer passing the buck Space is not an issue (if it was then the Env Agency often gives permission for infiltration tunnels.) We haven't tested the percolation yet , but my guess from observation is 80 s/mm. That gives us a crazy amount of trench approx 250m long, maybe more. We don't want a reed bed. A drainage mound is worth a thought. When I first used these digesters, as a new thing, the regs and BCO were perfectly happy with percolation through French drains as if it was rainwater.. ie 30m or so. The tanks are very much better now but the regs have gained this ultra-cautious approach. As I read in a sales blurb... "written legislation has fallen behind the technology available" Agreed. They then say that while the legislation has not caught up, "local authorities and Building Control have'. If only. Unfortunately I can see no sign of that unless the land is too small. The digester company cannot offer help. I'd have thought that saving customers money without affecting their own cost would be good business, but apparently not. eg they make a special model to reduce phosphates even more, but that doesn't make any difference to the soakaway area. The other manufacturers appear to say even less. It's not only stinginess (otherwise known as efficient and sustainable design): I simply don't think it's sensible or necessary. It is very simple how digesters work, as a flush of the toilet almost immediately pushes the same amount out of the treated end of the tank. 3 or 5 litres? More with a shower. That will not travel far along a perforated pipe so all the phosphorous will be at one location, close to the tank, especially in summer when the ground is drier. The regulations are assuming a day's worth all rushing through at once. BTW in passing I have read The real issue is of preventing phosphates from reaching the aquifer. that an orchard is an excellent way of taking phosphates out of the water. We will have fruit trees exactly there, but I doubt the BCO will be interested. This is the same principle as reed beds where the grasses absorb phosphates greedily and we would harvest it annually and... I guess compost it. Willows are good too, but at some stage need to be reduced and the timber taken elsewhere. A drainage field is regarded as secondary treatment rather than as a dispersal mechanism. Has anyone got a brilliant idea? Anyone used a drainage mound? Does it have to be a mound rather then below ground?

I like to stop a slab short of the inner leaf, then the ramp down is from there and the door bottom seal sits on a slope and water doesn't get through. This is because bottom seals dont really seal, but water gives up climbing the slope after about 50mm. To form this edge the shutter is simply placed against the inner leaf with any extra packing needed. This assume you now where the bottom of the door will be.