George

SE probably meant reinforced blockwork but was assumed to be unreinforced blockwork. Or different ground conditions were found. Either way I can't see you've got a claim against them- you had the choice not to build it.

I just wrote down what it would be, didn't bother with drawings.

Well I'm very intrigued by the use of AAC panels. They've fallen out of favour in the UK but I'd be very interested in see the design drawings and calculations for any AAC panel installation.

I've been involved in a few jobs where they've kept maybe a few walls from the ground floor. It' never worth it, demo and do a new build.

Oh we're all over the modelling software. I used a cousin of Fastrack for most of my day to day design work. The calculation of forces in an isolated structural system such as a truss isn't the hard part any more (although it can be time consuming and is now rarely done by hand)... what the engineer needs to know is what forces to apply to the model, in what combination and what the output means and whether it is acceptable or not. As yet you can't show a AI a house and get it to reliably work that out. It probably could one day but I won't hold my breath.

Currently available AI are language models and don't seem to be able to reliably handle mathematics. There's an ongoing thread on an engineering forum I'm on where we keep testing Bard, ChatGPT etc and it produces credible looking but mathematically incorrect answers to structural engineering (or complex maths/physics) questions. Entertainly on Bard you can switch between drafts and it sometimes give different answers in each. I don't fear for my job yet! There are standard designs of course and I wouldn't be surprised if someone out there has tried to market a truss beam replacement. But I've only ever worked on large trusses. I did see a footbridge made up of space frame trusses but that was in an awkward location so could be brought in and bolted together, making it worthwhile. And a footbridge is a relatively lightweight use case with repeatable applications. Structural steelwork rivets are obsolete in the UK. They're outside the scope of modern structural codes so wouldn't be acceptable to building control without a lot of effort. Drilling a hole in a steel beam, even if it required reinforcement, would be a lot cheaper than a truss. You should be able to get a 75mm hole (for radial ductwork) through a 300mm deep beam but would need local strengthening. If it's a main duct then could use rectangular ducting to get through . Even if you didn't have a fully coordinated design you could get a few designed holes put in.

I don't know whether there is a way to assemble the whole thing using bolts You could certainly have that designed but it wouldn't be a straightforward design and as you get smaller the influence of bolt holes removing material becomes more significant. I charge maybe £300 for a beam design... because I don't do it very often I'd probably charge £900 for a truss! Unless I could push almost everything onto the fabricator. or they have to be welded, in either case doesn't sound terribly time consuming You need to consider than a standard beam size required very little fabrication time and labour is the key cost. So with a standard beam you are mostly paying for materials. A truss only has a moderate reduction in material cost but many more times more fabrication. Each member will need cutting and prepping, lots more welding, flipping it over, weld the other side etc. Easy to handle - no lifting equipment required. A beam lifter is maybe £50 for a day. It's a minor thing. If it's prefabricated then no benefit. Easy to deal with services (the same as web joists). True but this doesn't really save any significant money. Can be left exposed and would look OK as opposed to a steel beam. A nice beam doesn't look too bad. A bolted truss would look a bit shoddy. A nicely welded truss could look good but a bit of a dust trap! Also need to consider fire proofing. It's not outside the realms of possibility. I'd say probably between x3 - x8 the cost for a standard beam.

Double chord at the top because the chord in compression is liable to buckle, whereas a single large tension chord won't buckle. These are massive and as you reduce the size the relative cost of fabrication increases. A truss is used because the additional fabrication cost is worth it for the reduced material and weight saving (and some architectural value too). You wouldn't change a 300mm deep beam for a truss because the fabrication cost would many multiples of the cost of the raw steel. Many years ago when steel/iron was costly and labour was dirt cheap, you sometimes found small trusses. But aside from prefabricated things like metal web joists and roof trusses you won't find fabricated steel trusses at a domestic scale.

They make a noise, but I wouldn't call them noisy.

I'm afraid that's about the going rate at the moment. The nominal agricultural value (£8k to £12k an acre) only applies for large tracts and should be considered as the absolute minimum. £16k for land immediately adjacent is quite a bargain. I've seen some go for £20k/acre for scrubby woodland. Paintballing doesn't sound the worst development but on a constrained site might cause issues. But they'll pack up when it gets dark and doesn't cause loads of traffic

Suitable fixings to stop them dropping off in future would be my concern. I'd rather go for a jetfloor type system, or lower the floor and increase the insulation on topside.

Please take it down asap as it is dangerous and not economical to rescue. There are cases of children being killed by falling walls. I myself had to dodge a wall that had been severely damaged by ivy - I'd probably have survived but could easily have done serious injury.

Me or Gus. Gus is Scottish I believe , so judging by your username he's probably best placed... although the laws of physics remain constant. Although there's always another structural solution, engineers will tend to go for the most economic solution either in simplicity/buildability, materials or time. If you or the architect hadn't given them a clear constraint then they may well not have appreciated the importance of the beam positioning. (Also any opinion we give is only in general terms, if an engineer comments specifically on a project then really they should be engaged and make contact with the original engineer.)

Anywhere between L/18 to L/24 would be fine for a first stab. It really is just as an estimate to avoid an architect leaving 100mm void for a 5m opening. If supporting external walls etc then L/18 is the better end but there's always the get out of heavier weight or UCs.

Interesting design If you want a rough estimate of a beam depth use the ratio L/24 (L is the span, same unit for the beam depth, rounded up to.ansection designation - this is very rough and ready but is the only structural calculation I'll let an architect do). RC roof slab will be very expensive because falsework mobilisation costs will add up. Hollow core or just precast planks with a structural topping, or just composite decking, would be better.

Take the cladding right up to the top and screw a bit of power coated mild steel with a star cut out on the outside. Otherwise the interface between the star bit and the cladding is just a nuisance and, frankly, not something the architect should have washed their hand of.

Oh well now I wish I'd have done that.

£30 a day is a bit bonkers. Our energy use (Inc a 16kW ashp) peaked at £100 in a week but that was for everything including our biggest luxury of an Everhot. No EV charging though

Have you looked at he HSE run site https://selfbuildportal.org.uk/healthandsafety/ They describe the above. In short, yes if you are the Client but are also directing work and haven't appointed a PC and are also quacking like PC then you are the PC.

1) use this chart for brick dims https://www.wienerberger.co.uk/content/dam/wienerberger/united-kingdom/marketing/documents-magazines/technical/brick-technical-guidance-sheets/UK_MKT_DOC_Brickwork%20Dimension%20Tables.pdf 2) probably not if it's a cavity wall but it depends on the location. Brick piers are usually used on single skin walls to increase the effective thickness. 3) you probably won't need MJs in the brickwork as it's less than 12m. But as a safeguard I'd use a M4 mortar with hydrated lime and cement. If you wanted to be sure you could add bed joint reinforcement every third course... I'd rather do that than put MJs in external leaves. The blockwork inner leaf will need them. 2 in the back wall, 3m from the corner and 1 in each side wall placed centrally. These should use slip ties. Fee £300 please Edit - just a thought, there could be a significant point load from the girder trusses, did the truss manufacturer give any guidance on what support was needed? I'd suspect not so potentially you'd need piers to support those.

Agree. A span of 1m , even allowing for the pitch, is fine for a 4x2.

Natural stone is likely to crack from the thermal expansion and contraction fracturing any discontinuity in the stone. If you don't want joins then cast refractory concrete died black should work. The sides could be black stone so long as they're not in direct contact with the fire. I don't think there's much point insulating an open fire. Only really makes sense for pizza oven type set ups

You'll need to add some pictures because I don't understand the issue

No - the extra cost in formwork and issues with getting good compaction means that either a thicker slab or a precast beam & block system would be better.

Upright between the gap in the mesh. But whoever specified the links should be able to tell you.