saveasteading

In this case it does. lots can go wrong, as listed above. You must prepare as much as you can, to make it easy on the day. Any one thing needing attention will cause other knock-on effects. And the lorry has a time limit. I hadn't thought to mention the mess, but what a good point to emphasise. The washout is a messy process, and the last delivery should have some surplus in it unless you have undermeasured. It will be a big heap on your ground tht will go hard, or that you have to destroy with masses of water, or you barrow somewhere else. On that, when the trench is complete and marked for levels, you can take cross sections to calculate the quantity you need, and revise the estimate order accordingly. I work it out exactly and add approx 0.5m3 for wastage and to ensure it isn't short. If there is between a barrowload and half m3 surplus then that is good. But 1/2m3 takes a lot of spreading...do you have a use for it. I'm talking about projects where being short creates structural or aesthetic issue. On a trench fill you can always get the bricky to build higher or eve add some hand mix. So on yours you could go for the exact amount. Another thing you can do with multiple loads is ask for them to be spaced out, so you have some recovery time. ie not half an hour apart.

I once had to work with a client's architectural technician who wrote "latest" in the box labelled 'issue'. I thought he was winding me up but no, it was what he always did.

Good job you found it now rather than when the walls missed the foundations. It might be worth a spring clean, and delete (or hide away) all the drawings you have and get the architect to send new, clearly labelled 'construction issue'. Then issue them to anyone else who might need to change them. I have a warm glow from suggesting you check it in the twilight. "Yes I would, because people make mistakes." Let this be your mantra throughout. This all maters much more to you than to them. @SteamyTea your drawings are a great explanatory. In real life, I was going to say that the error would not usually be in having a non-square corner as a starting point. But with every little builder now having a Lidl laser, I guess that is quite likely.

Is that assuming another finish will cover it? eg carpet/ tiling? I've never seen it but have seen the ripples in flowing screed. I've looked up the blurb and it seems to mention mainly that it flows around reinforcement and complex shapes. Flooring is mentioned less, and one reference said suitable for domestic (implying only domestic?) and that it doesn't need a screed over it. It's surprisingly difficult to find out more, especially technical stuff about strength and surface tolerances. any references would be welcome as I dont like to not know this sort of thing. @Nickfromwales presumably you've used it. Is it like screed finish? What cost relative to old fashioned pump mix?

How did you notice the error?

So change it / get it changed. He can use the correct drawing next visit. Meanwhile, you have a rectangle marked out too small by a known amount. So you can prepare the area. Perhaps postpone that concrete pour. It's not simple, as you are finding.

Yes I would, because people make mistakes. Presumably the pins are in the ground at the exact spot, so you measure to that, or to a spirit level up from it. Also check any critical distances, for example to an existing feature or a boundary. I would also do as I said earlier and take references, but it is up to you. This is in case a pin is knocked over. It is simple to place offset pins or pegs. Project the wall lines you have, and put a mark in 1m (typically) beyond, at each end. If using a peg, put a nail in the top. You then have 8 pegs. If you wish , tie an orange stringline between them and you have your rectangle, increased by 1m. Then the digging can all be within that, and you have an immediate check. you may also be saving a visit or 2 from the total station.

later so that they don't feel threatened/ doubted, and so you have lots of time to get the hang of it. I think you said the site is sloping. The tapes need to be tight and horizontal. if necessary use a spirit level to bring one point op to the level of the other. Then don't panic if it is a few mm different. the diagonals exaggerate any differences and you have more opportunities for precision as you come out of the ground.

It has landed on the concrete. That's better than some.

If it is complex, your average builder won't use it.

In the past, fibre was elastic and only for rough work, and you learnt how tightly to pull it. Steel was accurate but vulnerable to damage and rust, and even temperature affected for precise work. New fibre tapes are accurate, and ,as you say, in different grades... clas 1 or 2 will do. Open reel fibre is best for groundworks stages I see SF sell class 3 own brand for £10. But Stanley for £20 looks my choice.

I hadn't heard of that argument. That is becoming rather desperate as an argument for crittall. Presumably then, the better made a crittall is, the less this happens.

OK that works. Lethal to fall on so be ultracareful.You can alternatively bang them in the sides, even using big nails or lath.

Double glazing at triple the cost.

Agreed. But as I say to everyone. Do not add any water to the supplied mix. That spoils the concrete but also remains as liquid water and might freeze. If using a builder tell them this strictly and also the concrete driver. No added water. If requested the driver insists on a signature to absolve his company. Your concrete will be safe after about 4 hours. @flanagaj you haven't set out the building, let alone dug the trenches. Ambition is great but assume there will be challenges. You may hit obstructions. How are you going to control the concrete level?

WhatsApp for messages and queries.

Doing this currently. Handsaw ( multipurpose) for small cuts. Circular saw for longer cuts. And mask, goggles, hat with the latter. I had expected the eps to shed whole 'bubbles' but it cuts as very fine dust. So do it indoors or you will contaminate the area.

I've come to realise that you can either do this or you can't. And that many builders assume that by using lasers there will be no issues.

You can have mine. I was brought up on theodolites and tacheometers when simple total stations were just invented. We were told that without using the manual machines we wouldn't understand the full implications of the built-in inaccuracies and geodetics. That is true. The worst setting-out I ever saw was by a guy who claimed to have been a surveyor on Eurotunnel. Using a total station he set the rectangular building out with splayed sides... so wrong that eyeballing or pacing were much more accurate. It's quite a skill using a total station. Under some staff pressure I bought one at great expense. Nobody used it and we carried on using tapes. Anybody want a Leica Total Station? Was £14K, I'll settle for 2 as it's quite old but barely used.

Agreed. Your physical boundaries are what matters and seldom as OS, or even Land Registry shows. I won't bore you with my stories and cross my fingers for you that the project fits in the space available.

It wasn't stretching , simply very inaccurate. I can't remember how I discovered the problem. Probably used a different tape. I got my money back of course but refused to return them in case they sold them again, and binned them. Good fibre tapes are now very accurate IF stanley etc. That's great, but you do need to take references off it, or you'll have that great price 5 times.

And the pipes are now carrying warm water a long way, so need very serious insulation. It's standard stuff but expensive. When I had this at about 10m I used the double core insulated product but added more insulation over the top.

That is likely. That way or using tapes and triangulation doesn't matter. Please remember that they will mark stuff out and the very next operation is digging it all out again. So either they or you should provide reference points that you can refer back to. throughout the process, so that they dont have to repeat the operation. these can be offset pegs from their references, usually 1m parallel to the grid lines. Plus you can measure to permanent features such as fences or poles. a nail into these is good as it stays put and will hold the end of a tape. We can discuss that more after. and triangulation. If using a builder then you should discuss what they need from you, and what they will do if they dig out or knock over an markers. RE slopes, if you hold a tape horizontal, and pull tight then the slope difference is removed. The fact that you recognise this is very encouraging and you probabaly wouldn't believe how few do. Buy a 5m steel tape and a couple of 30m fibre tapes by recognuised brands. I once had 2 x steel tapes, 'silver something or other', from SF that were inaccurate 100mm over 30m! that could have been very expensive.

A service cavity filled with mineral wool isn't accessible any longer. Just partially fill? Your thermal bridging is through the studs but this will be calculated... it is normal. Have you a target for insulation or throwing all you can at it?

Ours are aluminium. We have a few of the crittals left, because they weren't rusting and falling apart... yet, so can compare. Nobody sensible would insist on steel. If you ask your local glazing suppliers, or go straight to the manufacturers they may have info on approved replacements in the area. They also may have publicity to help you. I'd apply with a detailed proposal... this now (emphasise the problems.)... this proposed. Preferably showing a similar construction.