Jeremy Harris

The braces are essential to prevent buckling failure of the yet-to-be-tied inner wall skin, under the compressive load of the first floor, applied to the top of the inner wall skin. Once the two wall skins are tied together they become a great deal more resistant to buckling failure under a compressive load, because the slenderness ratio has decreased. If you want to try and get your head around this you can either read up on buckling, crippling and slenderness ratios under compressive loads (tip: search for work by Euler, the 18th c mathematician), or you can do a simple experiment. Take an ordinary straight drinking straw (not the fancy ones with bends in) and stand it vertically on a hard surface. Push down on the top end with your finger and you'll find that it will buckle and bend in half under a quite modest load. Take another straw, and this time just very, very gently hold the mid-point between the thumb and forefinger of one hand (simulating the bracing) and push down on the top end with the other hand. What you'll find is that the maximum compressive load that the braced straw will take is a lot greater than that of the unbraced straw.

There's been a bit of Siga Sicrall stuck to the side of one of my long levels for around 3 years now. It's been left out in the rain, bright sunshine, covered in concrete and washed off and I've tried to pick it off a few times. It's still there, and short of taking a chisel to it I don't see it coming off in my lifetime...............

For info, we lost around £450 as a consequence of our kitchen supplier not understanding the self-build VAT rules, despite me giving then a written copy that's still in their file. It was, admittedly, partly my fault, for not checking all 48 items on the invoice individually and carefully, but they've admitted it was primarily their error, but aren't going to refund me.................

Not being WRAS approved isn't a biggie, as the thing has to be enclosed in insulation, anyway, so will be well out of sight. Plus, my experience was that the BI didn't check anything for approval on the water side, even the jobsworth interim bloke who went on and on about meeting the water consumption regs. Those PHEs are made in exactly the way the ones in a combi are made - stainless steel plates copper brazed together, so they would get WRAS approval easily, it's just that, being German, they don't need too. Yes, the pressure drop is negligible. Our whole system runs at between 2.5 and 3.5 bar (2.5 bar is the borehole pump cut-in pressure, 3.5 bar is the pump cut-off pressure) and there is masses of flow available on the hot side.

We looked at running across our neighbours garden, as that was an option the water co suggested during the site visit. It shortened the run from 140m to around 90m, and when I spoke to the neighbours concerned they were fine about it, as long as we did the work quickly and made good their garden afterwards. In our case it was no cheaper than going up the lane, though, by the time the legal costs of the necessary way leave was accounted for. I'm just waiting for the water co to replace the 1 1/2" iron pipe in the lane in front of our house, as they didn't know it was there originally (despite them having a fairly new stopcock marked "Wessex Water" at the end of it!). When we asked all the utilities if they had anything under that lane, as a part of getting the highways licence to dig across it for our drainage, the water so wrote back to me saying they had no pipes there. We found the old pipe purely because our ground works bloke said he never, ever trusted the utilities, so he went very carefully and found this badly corroded pipe. He called me to look at it, we followed where it was going and found the stop cock for the house opposite in the verge. I called the water co again (by this time I'd already decided to have a borehole drilled as it was cheaper) and asked if we could connect to this pipe that they didn't know they had. That's when they classified it as a communications pipe, primarily just to stop us connecting to it. Around two weeks later they sent a chap around to look at where that pipe ran, using a detector and marking the lane surface with a spray marker. I went out and asked him about the pipe, and he said that now we'd found it they were going to add it to their plans and schedule it for inspection. When I told him that the pipe had been laid in 1934, as the neighbour had records of the water supply being put in, had lived in the house his whole life (he'd been born in it, as it was his parents house) the water co bloke said that it would go on the list for urgent replacement, as they were replacing all cast iron pipes over 60 years old. So, I went back to the water co and said that if they were going to replace this pipe soon, could they bring forward the replacement date and I would make a reasonable contribution, say around £10k, towards the replacement cost, if we could have a connection to it. They refused, and said that I would have to pay the whole cost of replacing that pipe if I wanted a connection, so I just told them to f'off, in polite terms. They still keep pestering me to have a supply from them, even now. About every six months I get a letter from them offering me a water supply; each time I reply that we now have a private supply and aren't interested. I did run a length of 25mm MDPE down to the edge of the lane, though, blanked off, but connected to the pipe that feeds our front outside tap, that's also connected back via 25mm MDPE to the water treatment shed. I did this because we had a trench going down there anyway, and I thought that it wouldn't hurt to have the option to connect to mains water when the water co eventually get around to replacing that pipe. The mentality of the water co seems odd to me. They know they are going to have to replace that pipe soon, at a cost that's not a lot less that the price that they gave me for a supply, I suspect, as the total run of that pipe is around 190m. If they had half a brain cell they could have seen they were getting a bargain if I offered to pay around half the cost of the pipe replacement in return for a connection to it, as not only were they saving money, but they would be gaining a customer, and hence an additional source of long term income.

The problem has never been not having enough homes, it's always been about not having enough home in the places where people want, or need, to live. There are still streets full of cheap or empty homes in areas where there's no longer any work.

You could also consider fitting one of the cheap, DIN rail meters, perhaps together with an RCD, in a waterproof box at that junction. I fitted one of those small meters to my electric vehicle charge point, just so I can record the energy use, they aren't expensive and are even approved to the right accuracy spec for charge metering, and they are pretty versatile, the one I have reads energy since installed, a resettable energy meter a bit like a car trip odometer, the PF, voltage and current, just by repeatedly pressing a button. Be good to have an RCD as well, having experienced the state of some contractors electrical kit, like the guy we had who's trench pump had a fault that made the case live (albeit through an internal leak of around 600 ohms), and had probably been like that for some time, as he had it on a bit of rope and so had probably never touched the case with it running. The leakage could have been enough to kill him, had he ever touched the thing when it was running from the mains.

One of the most useful things I've ever borrowed. I didn't believe how well they would stick to steel until I used one, years ago, when doing an "evening job" as a sideline, helping my brother out by fitting an engine room alarm system to the Torpoint Ferry (it was in Falmouth Docks being cut and stretched, and my brother had the contract for the engines and hydraulics, but gave me the job of designing and fitting the engine room alarm system). I borrowed his magnetic drill loads of times, to drill holes in steel bulkheads. Brilliant bit of kit, but not something I could ever justify buying.

I'm with Dave on this - it's the building regulations that determine a lot of the spaces in, and around, new homes. Those regulations are designed to ensure that ALL new homes are able to be lived in by anyone, whether able-bodied or disabled. For years we've been making homes more accessible, for people with limited mobility, impaired vision etc, so do we now decide that we are going to have two categories of new houses, those for able bodied people only and those that can be lived in by anyone? Much as I dislike having to have sockets half way up walls and light switches too low, as well as ramps to external doors, low door thresholds etc, I can fully understand why we have those regulations. My father was disabled and a wheelchair user for most of the time I knew him. Our 1930's built house had to be extensively modified to allow him access; all the ground floor doors had to be replaced with wider ones, a shower room had to be added as an extension, a sixth bedroom had to be built as an extension on the ground floor and even then there were areas he struggled to be able to access. I have a good friend who's paraplegic, and usually uses a slim and lightweight wheelchair, but can use leg braces and crutches to get about (slowly) using just his upper body strength. He cannot get into our current house in his wheelchair, just because of the combination of steps at both doors and the sharp angle between the door opening and the hallway. Those here who've visited our new build will have seen that I've fitted wide doorways everywhere, and that we have flat thresholds for all the internal doors, There's also a gentle ramp, with a wheelchair turning area outside the back door and I arranged the size and position of the downstairs WC to accommodate a wheelchair alongside the WC, to make transfers easier. I went a lot further than Part M requires, purely because I know that my friend wants to come and visit. I even had him visit during the build, before I fitted the downstairs WC, to get his opinion on things, and his feedback led to me fitting that WC on a 30mm plinth, just to make it easier for him (or other wheelchair users) to use. As this is to be our last home, I also thought about things like being able to get upstairs when we're older, and put in bracing and mounting points behind the wall alongside the stairs to make fitting a stair lift easier. I also left space at the bottom for it to be "parked", out of the way. Finally I designed my study, on the ground floor, so that it could easily be converted to a bedroom with a shower and access to the downstairs WC if it was ever needed. So, micro homes are a neat idea, but inherently discriminatory against people with limited mobility. Are we OK with that as a concept?

Being a former applied, rather than pure, scientist, I feel a bit of measurement coming on! Next week I'll retrieve the portable data logger from the water treatment plant shed (where it's been checking to see if my frost protection system works OK since a couple of weeks before Christmas) and bond the remote temperature sensor as close to the centre of the slab as I can get, and take a week or twos worth of data and see how it compares. The room air temperature sensor on the main house data logger is pretty close to the centre of the ground floor, and the sample times are more or less the same (give or take 30 seconds) so in a week or two I should have data on slab surface temp, slab internal temp (50mm down from the surface, the slab is 100mm deep), ASHP flow temp (shows when the heating is on), room temperature and outside air temperature. The loggers record every 6 minutes, so there will be a fair bit of data, and it should be a fine enough resolution to be able to see the response curves. Unfortunately I don't have sensors on the UFH flow and return, and right now can't easily add them, as I've run out of DS18B20s, and although I have spare ports on the data acquisition unit downstairs I'd need to add some code to read a couple more sensors and add it to the data file on the SD card. However, it would be a safe assumption to just assume the UFH flow temp is 24 deg C all the time the heating is on, perhaps adding a lag of a single sample period to allow for the opening time of the UFH thermally actuated valve. Would such a data set be of use?

I agree that physical security has to be the better option. I don't think alarms are that effective, as so many people just ignore them, them until they have been sounding long enough to be a nuisance. I wish that external door and window roller shutters were a bit more affordable, as they offer the dual benefit of reducing solar gain and enhancing security.

That's good news, and, I suspect that's unusual, too, to get the car back in one piece. The fact that ripping a box off a wall disables an alarm is amazing. I've heard of the expanding foam trick, where the scrotes get up a ladder and squirt can foam into the housing to silence the alarm, but not just ripping the thing off the wall!

I second the above! I saw a cutaway model of the Biodisk and my immediate thought was "how the heck do you maintain that?". The ideal of having a motor, gearbox and drive belt inside a chamber filled with effluent struck me as a sure-fire recipe for maintenance problems. There are loads of well-made air blower systems that all seem to work well, and the Puraflo system Crofter has mentioned is well-proven, the only slight issue being you need some space for the tertiary treatment part, but that's not often a real problem.

FWIW, I did some rough-and-ready calcs on probable vapour movement for the outer edge of our Larsen truss, where 200mm of it sits on a DPM that's on top of the EPS upstand around the passive slab. The vapour permeability plus the relatively low heat capacity meant that there was an extremely small risk of that area getting near dew point, even with some pretty severe local external temperature and humidity swings, and that was with a higher decrement delay insulation than you're using, so I think your risk is probably even lower.

The problem I have is trying to, very delicately, explain that her work is total crap, and that when she's gone I'll have to undo it, clean it off and do it again. It has led to some sticky moments. The best example was oiling the doors in the new house. There was me thinking that if I rub them down, wipe them over with some white spirit, so they are ready to oil, I can give her a pot of oil and a decent brush, put some newspaper down under the doors and just explain gently that the oil needs to be worked in pretty well, to do a small area at a time, make sure there's an even coat all over the door and to try and brush with the grain. What did we end up with? A dozen doors that I had to clean off with white spirit after she'd gone, around £50 of wasted Osmo oil and a couple of days of my time wasted re-doing them all. Sadly, she noticed. She looked at what she thought was her handiwork a few days later, said she was surprised the doors looked as nice as they did, then asked me outright if I'd re-done them all. I couldn't lie, but I did have a day or two of the "silent treatment" afterwards. The problem is you can't win in a situation like that, unless you're the sort of person that can look at something not properly done for years afterwards and not let it bother you (I can't.............).

OK, I've just checked all the correspondence we had back in 2014 with the appliance suppliers, and found a spreadsheet I made up to compare all the dimensions of different combinations of units, as there seems to be little in the way of standardisation. The oven is 542mm deep, which tallies with what I remember, as the ventilation gap at the rear of the oven housing is around 30mm to 40mm deep and leads to a grill at the rear edge of the top panel and is open to the space under the unit at the bottom. According to my spreadsheet, the maximum depth of oven we could fit was 555mm, from the edge of the front edge of the unit to the rear panel.

Sorry Dave, but the unit we bought wasn't really very open at the back at all. I don't know whether that's unusual or not, I've never fitted a tall double oven unit before. Ours had a solid back, with two slots around 200mm high in the back above each of the two oven compartments. These slots were shown on the 3D sketches of the units in the catalogue, but I couldn't get the dimensions of them from the supplier. The shelves to support the ovens was firmly fixed to the lower edge of the back panel in each section, to add some stiffness I guess. It meant I had to do some faffing around to get the top oven to fit, as it was about 2mm too high, so I ended up cutting four shallow rebates in the shelf where the metal "feet" (really just projecting parts of the bottom panel) were, to get things to line up neatly, with an even gap all around. Originally I wanted to get the whole electrical installation signed off in one go, and didn't want to bother the electrician to come back to wire up the outlets behind the kitchen unit later, so the plan was for all outlets to be fitted by him, tested and signed off, and then it would be fine for me to just fit the ovens and plug them in. Best laid plans and all that..................

There is case law on this, posted in another thread here: Might be worth a read, as the Council Tax still uses the basic rating valuation law that goes back many years as it's underpinning legislation.

That's similar to my experience, although in my case I was using the ASHP to preheat the thermal store and then an immersion run mainly from diverted excess PV generation to boost to 75 deg C, initially. For heat loss, and resultant room overheating problems, I reduced the thermal store down to 65 deg C. Practically, I've found that the 5 kWh Sunamp PV provides the same, perhaps better, performance than the 210 litre thermal store did, in a package a fraction of the size and weight. My gut feeling is that a thermal store probably equates to a UVC of around 2/3rds the capacity, or thereabouts.

Without wishing to cast aspersions on the particular water co, I share your view!

I like the idea of grid units like this. We fitted a combination plate in the living room with a grid sector in one of the four isolated quadrants, and it was really useful to be able to pick and mix speaker connections, ethernet etc in one panel. My only criticism of the MK system would be the price. The combination plate was reasonable, but the four quadrant steel back box was a ludicrous price, something like £40 or more. It was also slightly more awkward to fit, as all our back boxes are fitted to glued and well-sealed ply spacers onto the airtight/vapour tight membrane, with all the securing screws individually sealed to maintain the integrity of the vapour barrier. Not an issue for the smaller boxes, as a squirt of sealant behind followed by prompt placement on to the ply spacer was pretty easy, but the electrician did need an extra pair of hands to fit the big grid back box before the sealant started going off - it was one of those "three hand jobs" (stop sniggering.............).

I agree with all of that, but find the boiling water tap recommendation a bit odd. Ours was supplied with an under-sink filter head and a recommendation that a water softening ion exchange filter cartridge be fitted if the water was hard! I've just fitted a blank cartridge now, and had I known that we were going to end up with a water softener than I'd have left the filter head off and plumbed the thing in directly. I still have the new ion exchange cartridge it came with, and it's just a pre-charged water softener ion exchange medium in it, the same stuff the window cleaning guys use. Although the cartridge is intended to be a one-off use item, I dare say running saline through it would regenerator the ion exchange resin, just as it does in a softener.

I feel for you with this, as I ended up with the view that the water companies try and make things as expensive as possible when it comes to new connections. Part of that may be that they are bound, by law, to offer a supply, so feel they can just be lax when it comes to making sure their future customer gets a good deal. There is also a bit of narrow-minded thinking, that means they tend (in my experience) to want to run pipes up entrances. When the chap came around to look at how best to give us a mains water supply, he found the main and then started measuring the distance down the lane. He went about 10m past the corner of our plot before I asked him why he was measuring down so far, and why we couldn't run the main in at the corner nearest the lane. The chap just hadn't thought about it, or the cost of digging up around 12m more of road, until I suggested it!

They back dated the charge to the date of the application, though, as we found when we had to pay three months back Council Tax, that we didn't know we owed!

If you go back in the mists of time, radials used to feed things like immersion heaters, directly from the fuse box, were very often colloquially referred to as spurs. Officially, there was a tightening of terminology in the regs many years ago, so that a spur now refers specifically to a single cable to an outlet fed from a ring and a radial refers to a single cable, with one or more outlets, fed by one end from a consumer unit termination. I made an error, but frankly it was an age related one. Words and their meaning change with time, and terms that were perfectly well understood 40 years ago may now have a very different meaning, in all aspects of life. Edited to add: Sorry, forgot the answer - age again................ You can hide switches as long as they are readily accessible, and generally the Part M accessibility rules are pretty good guidance. So putting them behind easily accessed panels is OK, but think about wheelchair users and the like. I've been told (by my electrician) of a case where the oven isolating switches were allowed to be fitted at the back of the top cupboard, and were passed by a building inspector, but I took the view that that would be unacceptable, because my dad was a wheelchair user, as is a good friend, and I had a bit of insight into how un-wheelchair-user-friendly things can be.