MJNewton

Aha! That's the meter @Hastings hired too, but he only went and lost his copy of the calibration certificate! What is he like?! Any chance you could photocopy yours for him? ?

At the risk of sounding like a right old party pooper those tolerances will only be the outer cut dimensions. Everything else is subject to tolerances relating to bending metal, presses that must allow the release of the formed piece etc and so won't necessarily be quite so tight. If I were you I'd check what the returns policy is and make sure you can send it back if it looks like it's going to work out. Distance Selling regs mean you are entitled to do this of course to allow the equivalent level of right to inspect were you buying it in person but it's usually far easier if there's an explicit returns policy that supports it without hassle. Edit: Cofaro appear to be based in the Netherlands so returns could be problematic.

This document might be of more use as it is a bit more specific about actual dimensions: https://www.abodedesigns.co.uk/downloads/specifications/aw5128_specv2.pdf (Do check I've got the right one here!) Of particular interest is the inset requirements as whilst you are undermounting it with regards to the worktop you are in effect insetting it into a cupboard (or at least that's the Plan A Easy Route). It specifies a 735mm cutout which is some way over the 750-(2x18)=714mm that a minimally-modified base unit has to offer. Of course maybe they are just being generous with tolerances which brings us back to really needing the actual sink in front of you.

Exact dimensions of what though? That 710mm could well be the inner dimension as you say but what if it's double skinned and this and the tolerances of manufacturing might mean it is 720mm outer? It wouldn't slot into a 750mm unit with 18mm sides. Similarly, are they the top or bottom dimensions noting that most sinks of this type don't have vertical walls? I'd treat dimensions like this as nominal when it comes to steel sinks given the manufacturing methods involved. Where's there's a will there's a way though and once the sink is in front of you it'll be much easier to work out how to deal with it. Incidentally, I'd expect standard hinge position to be likely fine as it's only 400mm front to back and assumed it is centred will give some room at the front on a typical 560mm-or-whatever base unit.

Do you have the sink already, and can confirm the drawing dimensions? If so I'd expect a 750mm unit with 18mm gables will be fine and leave you with 2mm wriggle room either side. I've recently done the same with a Franke sink in a 600mm unit without issue and just a few additions to ensure stable support.

Note that those sensors are likely to be fake - genuine Maxim sensors have four zeroes in the last 16 bits of the serial number. Genuine ones are only a few quid more at the likes of CPC etc and removes any doubt about accuracy, longevity etc.

There's no such things as negative resistance reading so on that basis I'm assuming your meter it broken.

There's no such thing as 'too low' on a multimeter. Do you have a link to the manual? A meter scale goes from zero to whatever the scale range is for the position you've set it to. The '200' resistance position measures 0-200 ohms, with a higher resolution than that which would be achieved for the next one up - say 0-2000 or whatever it is. That's pretty poor and in my opinion warrants further investigation to work out where the high resistance is coming from - is it the meter leads (connected them together and take a reading), the extension lead (measure from one probe to the other) or is it your circuit (subtract the first two readings from the total) which might be in the circuit you're tapping into or the one you plugged the extension lead in. With a 20 ohms earth path a dead short would draw 240/20 = 12 amps. Whilst that'd trip a 6A MCB it wouldn't trip anything much higher. To put it into context - a 2 ohm earth path would result in 240/2 = 120A which would trip any sized MCB and in the shortest possible time.

For future reference, '-1' means out-of-range i.e. the resistance was greater than that for the set range. Given that you were measuring something that should've only been a couple of ohms tops and that 'striking the copper' gave a reading shows that you weren't making contact. Note that 'changing numbers' is not the result you were seeking for this test. Even a wet piece of string or even the probes held in each hand would give you changing numbers if the range was set high enough. Don't be misled by the continuity beep test either as that can often sound at resistances up to a couple of hundred ohms (the meter should say what the detecting range is). If you want to be sure then get an actual, stable, reading.

Do bear in mind, and I think I am right in saying this, that the Ofgem price cap is as you say the notional total for a notional household, however it is made up of two parts - a per-unit consumption charge and per-day standing charge and suppliers are free to play around with each as long as the combined total for a notional household's bill doesn't exceed the cap. You do therefore need to get *your* suppliers figures to see how the Ofgem cap change impacts 1) your suppliers implementation of the cap and 2) your offset from the notional household consumption.

Correct - scribing only works for internal joins.

I might be misunderstanding the context, but RCBOs have been common for a while now - and I'm not quite sure what the residential aspect is. Cost perhaps I suppose? Certainly they are useful for outdoor circuits as they are more prone to nuisance trips and so it can be really beneficial to not have those trips take circuits down in the house if they happen.

Can you elaborate? What specifically were they referring to?

If you plug an extension lead in somewhere and take it out to the light you can measure the resistance between the earth at the light and the earth in the extension socket and it should ideally be less than a couple of ohms. (Passing this test will also require your socket circuit earth to be present of course so two tests for the price of one!)

Don't forget a couple of blokes walking up top for maintenance...

It is beneficial to enable a dedicated 'outdoor' circuit to be added though so as not to cause nuisance trips of the RCD protecting whatever 'indoor' circuit you might otherwise tap in to.

I've been meaning to post a follow-up and I'm always disappointed when threads are left hanging! (What happened to that guy whos new build looked to be falling apart?) Anyway, the worktop suppliers were really good about everything - seemed to be genuinely concerned about trying to make us happy but also remaining sensible about the options which is all fair enough. On the two main points: - Colour - We've reached the conclusion that there's no fault on the part of the supplier here... It's just a combination of our room/lighting and the fact that the worktop isn't quite as white as we expected/hoped and, more to the point, never was - the samples have got pretty much the same tone to them but we'd never put one in the corner to view it (it had always been out on the well-lit island) and even if we had I don't think we would've spotted an issue. We have reminded ourselves that despite looking high and low for other options whilst this one was out of stock we never did find one that we loved and so this one probably is the best we're going to get and there isn't the 'perfect' one out there (that we're aware of at least - don't tell me if you see it!)... And we've got used to it, or are not so concerned about it - indeed I'd go as far as saying we're growing to like it now that we're looking at the kitchen as a whole rather than focusing on the latest thing to have gone 'wrong'! - Island bow - The supplier asked for some photos and then arranged for someone to visit in person (300 mile round trip!). The guy that arrived was actually great - who knew worktop problem rectification could be such fun. A bloke from Buxton with a strong northern accent but with Italian roots he was quite a character. It took a couple of weeks for the visit to happen and by that time I swear the bow had lessened as I'm sure I wouldn't have kicked up a fuss if it was how it was a couple of weeks later. He said he wasn't surprised given that the resin in a quartz worktop does lessen its rigidity, and he also didn't attempt to deny that it should've be installed/left like that in the first place. Rather than berate the installers we just discussed what best to do and the pros and cons of each option, including replacement. We ended up removing the sealant, spinning the worktop so as to reorientate the pattern to what we thought was a slightly better aesthetic (might as well whilst we could) and then found that the worktop actually fitted much better. Perhaps my units weren't quite as flat as I thought, but even so there was a measurable bow albeit not one you could feel or spot by eye anymore particularly now that it had flattened. He tapped in some shims - his thinnest ones - and I was content (pleased in fact) with the outcome. He siliconed up, we had another cup of tea and a chat about life and the matter was concluded. So, all's well that ends well - and another reminder to me not to assume it's the end of the world when things don't quite go to plan.

PEX is relatively stiff and so I tend to prefer the flexibility of Hep2O (PB). I've not much experience of the former though so it might not be bad in practice.

Same here. I'd suggest replacing the unit and making the most of the existing installation.

No. Notifiable work is limited to new circuits, replacement consumer units and additions/alterations in a special location (of which the kitchen no longer is).

I could imagine it could actually - the bound render effectively becomes a sheet and it wouldn't surprise me if it could gradually bend without cracking. Does it sound hollow when tapped?

It sounds like we might be talking about different things. I can't imagine anyone using semi-rigid radial ducting like the following for extractor fans. It's got an internal diameter of 68mm so it would indeed be a terrible choice given the flow rate of a typical extractor.

I'm nodding at all those points, although I've never measured its air resistance and it's not clear what the 'less work to do' is in comparison to (other than ducting with higher resistance of course!). Certainly as far as I'm aware it's working perfectly, and is doing so completely silently so I can't really think of any downsides. I suppose there is the issue that you have to buy it in large rolls and so you are at risk of over/under-buying. I sold what little excess I had though as there's often someone looking for just that little extra having run out themselves! If you've never had a piece in your hands more than happy to pop one in the post so you can get a proper idea what it's like. Of particular note is the internal lining which whilst ridged is what I'd call 'semi smooth', which of course is impossible to interpret accurately.

In what plane(s) is it bowed? It looks from the picture that it is certainly bowed away from the door frame (which you've confirmed is itself straight) but has it also bowed away from the wall too i.e. is your rendered wall bulging out? If it's just the former then perhaps the intended trim is indeed going to cover it. How big is the gap in the middle? If it will be covered, and the trim isn't a monstrosity, then that might be preferable to taking any other action (e.g. raking out the foam, removing the beading and render and redoing) in terms of the aesthetics of the end result. If it is bowed out from the wall then that would make me worry there's a void behind it now and that might cause issues in the future, but then that's the sort of thing I like to worry about and cause myself stress over... P.S. Forgot to add - the render (and the bead in the particularly) might well always have been bent and it is only the addition of the (straight) door that has now highlighted this. It's not something you'd necessarily notice if you're not actively looking for it, which again is something I do just to wind myself up.

Ah okay. The OP is in a house in this instance. Is drainpipe what's used in large installations? (Hope this isn't sounding passive aggressive - I'm genuinely intrigued!)