Jeremy Harris

Conventional ion exchange softeners don't change the pH, nor do they alter the mineral content, they just swap calcium and magnesium ions for somewhat less sodium ions. I think that Qooker (and Itho, as ours came with a similar warning about pH) are concerned that the water in some areas can have a pH below 7. Our non-softened water pH is about 7.2 to 7.3 and the softened water is identical. Same with dissolved solids, the meter readings are identical for water either side of the softener. There are places where the water can be slightly acidic, so have a pH slightly under 7, but I think these areas are relatively rare in the UK, as the water companies artificially "harden" acidic water with lime, or limestone filters.

Looking at that pressure loss curve I don't think I'm going to fret over it, TBH. With our shower running the pressure drop through the softener is only around 0.2 bar, and I can say from experience that we can't notice a 1 bar difference at any of the outlets, as that's the normal variation we get between the borehole pump turning on and off (it turns off at 3.5 bar and on at 2.5 bar). Given that a 1 bar variation seems to have no noticeable impact, and as we'd need to draw off at three times the shower flow rate to get a 1 bar drop, I'm not sure that it's something really worth worrying about, unless you have a low mains supply pressure. Our accumulators are on the hard water side, too, as they have to be in order to not put a reverse flow through the softener if one of the garden taps was used. As I mentioned elsewhere, if the pressure at the softener outlet is slightly higher than that at the inlet then it can overflow the brine chamber. Even with an NRV in line I think I'd be wary about fitting an accumulator on the outlet side, as NRVs aren't perfect one-way valves, they will momentarily allow a small reverse flow as they shut. I found this out with the ones I fitted to the water treatment system, at the ozone injection point, and having discovered this the regs that say you must have a double NRV on the incoming supply makes perfect sense; it's to prevent that tiny, momentary, bit of reverse flow, I think. If you have a high enough incoming mains pressure then the option of fitting a PRedV after the softener, to regulate the pressure to a usable figure, say 2.5 to 3 bar, might be an option. That way the pressure drop through the softener might well have no effect at all.

Whether you need to bypass the softened water is debatable, as our Itho Dolce 3 way boiling water tap specifically says in the manual that it should be fed from softened water, and was supplied with a water softener cartridge filter in the kit. We discussed this recently in another thread, a couple of posts starting with this post here, that might be worth a read about the health issues: Our borehole water is moderately hard, but high in iron, so we have some pretty comprehensive water treatment and filtering ahead of the softener. I have to say that the softened water makes a lovely cup of tea with the boiling water tap, and in our case the sodium level is so small as to not be anything worth worrying about. If you live if a very hard water area then it may well be that you end up with an unacceptable level of sodium in the water, but there are ways around that, by using a non-sodium ion exchange softener for the drinking water supply.

Our toilets are all floor-mounted, but a friend of mine is a wheelchair user, and struggles when he visits our old house, so I was keen to try and make things a bit easier in the new build. He came around before I'd fixed the downstairs WC, both to have a look at how I was getting on and so I could get the benefit of his knowledge. One consequence of that was that I raised the downstairs toilet up by 30mm, on an oak plinth, because with it at the standard height it was a bit too low for an easy transfer from a wheelchair alongside. I'm not sure how high the seat is now, but I can measure it and report back on Monday.

Not only do I agree, but I also think there are some things in a self-build that are worth doing just because of the pride you'll feel looking at them in years to come and remembering all you had to learn in order to make it. This brick is more than just a brick, isn't it? I had a go at making a hand-made brick during a visit to the museum at Ironbridge, years ago (it was supposed to be an activity for kids, but they didn't mind an old bloke joining in). The mould was a timber box and the clay was thrown into it really hard to get it to fill the box completely. The only release agent was a dusting of very, very fine sand and I think the chap showing us how to make them mentioned there was some sand mixed in with the clay, too. This makes sense, as a lot of bricks seem to have a sandy texture. The excess clay was cut off the mould with a cheese cutter wire and then the bricks stacked to dry. I remember being told that they would leave the bricks to air dry for a long time before firing them, up to several weeks, depending on the weather. The kids making bricks were given stamps to make their own decorations, initials or whatever and the fired bricks could be posted on a month or so later, IIRC. If you watch the TV programme "The Great Pottery Throwdown" there is a fair bit to be learned from there about how clay behaves, the sort of drying times and firing regimes used for different thicknesses and shapes of clay.

My own view is that our MVHR is changing all the air in the house at least every 2.3 hours, 24/7, at trickle ventilation rate, that increases to all the air in the house being changed in less than an hour at boost rate. Most of the extract air is from the kitchen, as that's the highest flowing extract duct, even at the trickle ventilation rate, and as our kitchen, utility and downstairs WC all draw fresh air in through the kitchen door, from fresh air feeds in other rooms, the chance of cooking smells escaping is pretty small. The MVHR really is very effective at removing smells. When we were painting and oiling the woodwork, there would be no trace of any "fresh paint smell" the next morning. I'm pretty sure this is just down the MVHR being many more times as effective at properly ventilating the house than trickle vents, leaving a window open, or whatever, probably because it's not really affected much by outside conditions and is running all the time.

My advice, in the OPs exposed location would be to forget about DIY tunnels made from plastic pipe, or even the domestic ones made from small diameter, thin gauge tube. You need a frame that will last and cope with being re-covered a few times, as even the best plastic degrades after a few years and has to be replaced. My mother's polytunnels, in an exposed moorland location, have tubes around 40 to 50mm diameter, with solid cross-bracing and anti-chafe tape on the outer edges, to reduce premature cover failure. The covers are heavy gauge agricultural polythene. The frames ends are concreted in the ground to reduce the chance of the wind blowing the things away. I'm pretty sure mothers polytunnels were second hand, frames bought at a farm sale around 30 or so years ago. They may well be 40 or 50 years old now, yet are still OK. Covers seem to last no more than about 10 years, though.

The major problem with an outside extractor in a house with MVHR is that when it's on you will get cold air draughts coming in through every fresh air feed. What happens is that you're sucking air out of the kitchen and fresh air has to come in somewhere, and the easy route in is via the MVHR fresh air inlets. The MVHR will go massively out of balance and so the heat exchanger performance will degrade a great deal. The result is that the incoming fresh air won't be heated to any significant degree and the incoming fresh air flow rate will increase to match the extractor flow rate. The result, in cold weather, will be cool air coming out of the fresh air inlet terminals at a higher flow rate, just to compensate for the kitchen extract rate. I posted somewhere else about how easy it can be to clean and refurbish the grease and activated carbon filters in a recirculating hood. I do ours about every six months or so, depending on whether or not it looks like it needs a clean. It's just a matter of sticking the stainless grease filter mesh in the dishwasher and refilling the carbon filter unit with fresh carbon granules (which can be bought in bulk pretty cheaply from fish pond equipment suppliers). This works well, and keeps the everything clean around the hob in our current house.

A fair few of our "receipts" weren't marked as receipts, but did have confirmation of payment info and the VAT number. One or two didn't have the VAT number and I went to the company website and printed off their terms and conditions which always had it on, and just stapled the Ts & Cs to the receipt. When I did this I pencilled a note on the receipt giving the VAT number and highlighting that it was on the Ts & Cs attached, rather than on the receipt itself. This didn't seem to cause a problem with HMRC. I even had to provide a Danish to English translation sheet with one receipt, as you couldn't make out what was the VAT on it. I had the same problem with a fair few companies not sending proper VAT receipts, almost all were online suppliers. I gave up asking after a while, as I got the same response as you've had, and HMRC seemed to accept it OK.

60 l/s is an massive flow rate for an MVHR terminal, and it would probably mean over-sizing the MVHR just to achieve that rate in the kitchen on boost. I'm not familiar with the Scottish Building Regs, but if that's what they say then they are a bit odd, as it means that the MVHR total efficiency will be poor 99% of the time, because the thing will have to be sized to meet a kitchen extract rate that's more 4 times that needed for full boost under the UK regs.

Not sure that's right, is it? The regs are different for whole house ventilation, I believe, as the very last thing you want with MVHR is an extractor that will massively unbalance the system and cause cold air to flow into all the fresh air fed rooms every time it's running. Column one in Table 5.1a in Part F does not apply to continuous ventilation, for that you use the figures in column 2, so there is no part F requirement for the 30/l/s / 60l/s hob extract if you have MVHR.

We had lots of till receipts that didn't have any name on, one or two that had both our names on and the rest all had my name on. None of them were rejected, and I am pretty sure they went through them thoroughly, as they came back with detailed queries, withheld a big chunk over an error on a single receipt and all told it was over three months between submitting the claim and getting all the VAT back. I suggest you try and put the claim in both names, that way if a receipt has either name on then you should be OK.

I think the SWA nut and collet are tight on the armour, or seem as if they could be, looking at a close up of the full image. TBH, the whole installation is pretty grim, especially as it looks like the CU is a lot newer than the rest, so one has to ask why someone would fork out for what was probably a consumer-side rewire and not get the incoming side properly sorted, especially on a place that's a holiday let. As someone with a bit of a farming background, I'd say it looks a bit like the sort of stuff often found on farms..................

The spreadsheet I knocked up to emulate the parts of the claim form where you have to fill in every receipt, add up the VAT etc, is here, if you want to copy it: http://www.mayfly.eu/wp-content/uploads/2017/01/VAT Claim Form 431 - Blank.xls It comes without any warranty, etc, but I used it and HMRC accepted it. There's an extra column added at the left to use a serial number - I found it easier to find receipts in the stack and organise them if I pencilled a number at the top right of each one. HMRC don't mind this at all.

I buy the odd bit of engineering plastic and Tufnol from these people: https://www.directplastics.co.uk/ I've never bought sheet from them, only bar for machining (nasty stuff to machine, TBH) but their service is pretty good.

This is the sort of thing that bothers me a bit about fitting a lightning protection scheme that can't cope with the very high peak discharge current - would it actually increase the risk when compared to having no big conductors up in the air?

As Nick says, but I'd add this, based largely on our experience. BT Openreach (not BT, per se) have changed the rules (and seem to do so regularly!) so one is never sure what applies at any time. We were told to fit an external BT66 box so that Openreach could terminate their underground cable to it. I did this, and fitted the BT66 box to the thick fence that houses our electricity meter box, and even ran the cable they supplied, through the ducting they supplied, to that box, leaving it coiled up at the base of the pole, ready for their connection team. I also ran a length of BT Duct 56 under our slab and up through it, and laid a length of gel cable in that for our in-house connection to the master socket. When they arrived to fit the master socket and make the connection, they questioned why I'd fitted the BT66 outside. I told them that was a ruling from them when we started and the bloke then said " we don't do that any more"................... In your case, I think I'd buy a BT66 box, some gel cable and gel crimps and fit a waterproof housing that will take a master socket and your router, with a means of safely getting power to it, then ask whoever you choose as your supplier to connect you up (they will contract with Openreach for this, you can't get Openreach to do an install without going through a supplier, even if that supplier is the other bit of BT). With luck, the Openreach guys who turn up will be OK about connecting to an externally mounted master via a BT66, but there's no way to be sure, as you are guaranteed not to get a reliable answer from Openreach themselves. You can buy the correct type of cable (gel for underground, or plain outdoor cable) and the BT66 box from a few places, including ebay.

As above, chat to the officer. Our house dimensions changed slightly, because of the 400mm centres system the build company worked to, and I just emailed the planning officer for advice. He emailed back pretty quickly saying it was only a minor issue and that he'd put a note in the file that he'd agreed the variation. He also said that generally small dimensional changes, as long as they didn't create a material problem (like having the building closer to a boundary than 1 metre) were usually just accepted as being within the reasonable bounds for error.

The internet connectivity problem isn't one you can fix for long, if you live somewhere where there is no generator back up to the cabinets. I know that Virgin Media deploy vans with generators to keep their cabinets going for more than the couple of hours or so that the backup batteries last (because we're unfortunate to have one of these cabinets just down the road from us and have to endure the noise from their bloody generator every time we get a prolonged power cut), but it seems BT Openreach don't do the same with rural broadband cabinets, so once the cabinet backup battery goes down, the connection goes down with it. Certainly the FTTC cabinet we're supplied from is like this; we have two or three hours of internet connectivity in a power cut, after which the cabinet shuts down until mains power is restored. This annoyed me when I found out about it, as I'd already installed a battery backup system that would keep the house network going for a couple of days or more.

Could make things worse, as it seems a fair bit of lightning-related damage is from induced current effects rather than a direct strike. Indirect effects of lightning are one reason cows die when a tree in a field gets struck - the lightning current flows down the tree and out along the ground (as the ground is far from being a perfect conductor). Cows may well be better conductors than the ground they are standing on, so the current runs up one set of legs, down the other, stopping their heart in the process (doesn't take much, 0.1 to 0.2 A will kill a human, not sure about cows, and a lightning discharge is typically around 30,000 A)

I think the problem is, how far do you go? When we lived in Scotland a big, Victorian, Gothic revival, three storey house got hit on one of the two front turrets. That had what looked like decent lightning conductors, with big copper straps running down the walls either side. The side that was hit still had a gash down the wall, where the stone had literally exploded, right behind where the copper strap had been (that got vaporised) . Admittedly that house was fairly high up, and someone must have realised there was a risk of getting a strike to have fitted the lightning conductors, but the structural damage was still so bad that they had to demolish around a quarter of the house and rebuild it. I wondered at the time if they'd have been better off not having the lightning conductors at all. As our new house is right at the bottom of a steep valley, it's not something I'm going to worry about, but I think that if your house is at risk then you either need to get fully onboard with a protection system that will work without causing extensive damage, or just not bother. A half-way house scheme might well increase, rather than decrease, the overall risk, I think.

It must vary from region to region, as here we have the system Dave describes, a kit in the post that you use to take three samples over three days and then post back. I've been getting one of these every two years for a time now, and haven't had to endure the more intrusive investigation (although have had that done once, years ago, and can still remember the effects..............)

Good point, should have used max Ze for TN-S rather than max for TN-C-S. With the same assumption, that the strike was mid-way along the cable, so Ze at the strike point was 0.4 ohms shoves the peak V on the earth in the house up to around 12 kV. TBH, I'm just a bit surprised at how high these voltages could be. Maybe explains why you saw big sparks coming out of disconnected cables, though.

I've already done this, and it was pretty easy to put together. I have a second hand industrial UPS battery, a 100 Ah sealed lead acid one, connected to a current limited switched mode power supply that is set to 13.4 V. The battery supplies some small switched mode DC-DC converters that supply power to the modem, router and switch, so our home network can run for a few days with no mains power. Overall, it's usually slight more energy efficient than running three wall wart power supplies, as the single supply charging the battery is more efficient and doesn't really supply any significant current to the battery once it's charged. Efficiency drops a lot if the mains goes off and the battery needs recharging afterwards, but I like having the ability to keep the internet connection going for a while. There is a limit, in that the battery back up in the local cabinet only lasts a few hours, so the internet connection does still go down during a prolonged power cut.

Lets have fun with some numbers and see what might come in on the earth: Assume: - Ze at the house was 0.35 ohms - The incoming cables were overhead for some of the route between the house and the nearest earth point - The lightning strike was midway along the run between the nearest earth and the house - The effective impedance to earth at the lightning strike point was half Ze, so 0.175 ohms - The lightning instantaneous discharge current peak was around 30 kA (seems to be the average figure used) - There are no surge arrestors on the cable Ignoring local induction effects (which may well be pretty significant) and ignoring reactive effects too, the peak voltage on the incoming earth to the house could be over 5 kV. The above is very simplistic, and I strongly suspect that the chances are that induction from a nearby strike is more probable, but if there were a few thousand amps being conducted through the ground, or another conductor, close to an incoming cable then I reckon you could still get pretty big induced spikes on the imported earth. Not something I've ever looked at, or thought about, before, so all the usual health warnings that I could be completely wrong apply.