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I have a thermostatic mixer shower running on hot and cold gravity feed (boosted by a pump) It's plumbed the wrong way round "Hot goes to cold" and "cold goes to hot" the result is to get a cooler shower you turn the temp knob clockwise and to get a hotter shower anti-clockwise - I will one day re-plumb it but meantime it's just me and Mrs Alien that use it and we rarely adjust the temp anyway - it works fine (It annoys me that I got it wrong a lot mind)

It may well do that - it may also decrease the pump speed if the gate valve is fully open It's why a little experimentation is useful Last year our average summer daily HW needs required 1 x 4.5 kWh per day - we didn't run out of HW between reheats every 24 hrs This year is 1 x 3.25 kWh per day - we don't run out of HW this year either Parameters I've adjusted are pump speed, gate valve restriction and HW tankstat temp setpoint I need a better hobby

To get your head around this we need to understand what we are trying to do. Objectives are in general terms: 1/ We want to prevent the spread of smoke and flames for long enough that folk can get out the house, or if disabled that the fire service can rescue them. Normally this is 30 minutes for a house like this. In no particular order. The onus is on the home owner to not set light to neighbouring properties, based on fire of London act 1667. The onus is also on the home owner to ensure that the structure of the house does not fall on the fire service and risk their lives. One great example here is below https://www.firescotland.gov.uk/news/remembering-the-cheapside-street-fire-65-years-on/ But roughly here is what happened The building's 60-foot-tall walls collapsed due to an explosion caused by the blaze that tore through the warehouse. @Great_scot_selfbuild until you get a grasp of these basics you ain't going to make progress. What this means in your case is that you not just need to protect the occupants but also the structure. Now until you understand how the structure works, what bits can go on fire, what bits you need to protect and what are sacrificial then any advice BC or other wise give you could be a complete pile of mince, you need to ask where does the buck stop! It usually rests with someone like myself, not BC! At the end of the day the law is likely to make you (me) responsible if you have an input into this design. Now I can see why you think, but the cladding could burn away, but if that is the case then you often need to detail the fire proofing for that case. Basically you need to stop fire and sparks getting up into the roof space or into window openings. You need to sit down and think this through. It's down to the detailing! Your builder is asking good thoughtful questions!

I've come across this statement: “Hep2O should not be installed in Continuously operated re-circulating systems (Secondary Hot Water Circulation / Ring main installations).” I was planning on using Hep2O pipework from the plant room to the end points, with the long hot water runs (20-30m) having a 10mm return line to enable circulation to avoid running taps, wasting water and waiting for the water to heat up. I was sure I'd come across this approach by others - is this something I should be worried about? if not, why not?

Hi Roundtuit, thanks for reply. Yup absolutely- but.. when I took out replacement fridge today, I looked underneath & saw the dishwasher & sink waste pipes dissapear way off twds RHS twds corner of other worktop cupboards. Simply no way (without all worktops & cabinets removed that is) I could get to the wall corner, to sure up around pipes with steel mesh. Anyway, my method of chopping all but 6" of Mum's fridge cable off, & adding a plug on, seems to have paid off. This meant I could separate the white extension cable from it, pass the female end of this thru sink cabinet back hole, then with a coathanger stretched out & a hook on the end.. looked underneath, & really rather brilliantly, fished/ hooked the socket out twds me, & mated it to fridge plug. Doddle then to put fridge back. Also then a doddle to undo out again, & add some flexi ribbed 20mm black conduit to sheath the white extension cable, which even I thought looked appetising to gnaw on. When I can stumble on such pipey numnums that is. Mum pleased. I thank you. Zoot.

Having thought I'd closed this topic off for our build, I find myself revisiting it as my builder (new to the project for this phase) who is looking at the timber cladding installation (diamond shingles) has raised a concern / query about the 9mm shingles and whether they are safe/compliant for our build. His background is large commercial / flats and so obviously this topic has consumed a lot of time and attention for him but from a very different perspective. Our build is a timber frame, Larsen truss walls with full-fill blown cellulose fill (continuous, no gaps/voids). The question which I'll be discussing with my PD when they're back is two fold: 1. Verify that this cladding (which I've seen used on other builds) meets BR and safety standards. 2. If our build is clad in a non-fireproof cladding, what is the point in fitting intumescent strips (where we still need airflow in normal use), if the cladding itself is likely to have burned away? (I haven't researched how quickly the strips expand vs. singles are likely to burn). For further background, our BC has reviewed the drawings and seen the cladding, we are well over 1m from boundary and he raised no concerns. Has anyone else found themselves having to 'show working' to prove compliance or assure others? For clarity: Single 2-storey, 4-bed private dwelling (well) over 1m from boundary, in England.

How about telling the timber industry Eg the TDA. Timber Development Association? If it is feasible then they could issue standard designs foc.

Dunno but the amount the cost of slate was reduced by was equivalent to quite a happy proportion of the cost of the solar system.

Thanks Gus. The main thoughts on the Staddle Stone thread are along the lines of assuming the top of the post is constrained by a connection that leave it free to rotate, would the Staddle Stone be a point of failure. So only really considering if the Staddle Stone could constrain the post vertically and horizontally, but not rotationally. I then assume that if you have a rigid body translationally constrained in two separate locations, it is then also rotationally constrained. Interesting, I was so focused on whether the posts were sufficiently supported in terms of tipping away or towards the house walls that I forgot to consider them tipping parallel to the walls. I can see that OSB/plywood on top or sandwiching the rafters would prevent that. I was hoping to have V-groove on top of the rafters so this could work as plywood. This has been my main quandary. Really I want the loggia to only place a vertical load on the outer leaf of the house. The weight of the tiles onto the top ledger should be about ((1.375m / 2) / COS(46)) * 77kg/m2 = 76.8kg/m -> 0.8kN/m. If I crudely double that for snow etc, I'm looking at 1.6kN/m order of magnitude which is the weight of 1m height of brickwork [ (1m*0.1m*1600kg/m3) = 160kg -> 1.6kN ], so easily within scope. Lateral forces on the brickwork are much more of a concern as they rely on the wall ties and or weight of brickwork above as I understand it. The weight of brickwork above isn't much for most of it at the possible height of any ceiling ties and is tiny at the height of the top ledger due to a large group of windows. I should have shared that image earlier I suppose, sorry. The knee braces could work aesthetically if they are needed structurally. The foundation pads are around 600x600x600 poured on top of larger concrete pads of around 1m x 1m x 1.25m. I agree that the vaulting with no ceiling ties is a much more attractive look.

One advantage for the DNOs if inverters are regulated by power rather than current is that if they wind the voltage up everyone's inverters throttle the current so easier on the grid. Our original solaredge SE4000-16, limited the current rather than power and with our base voltage being 25x vac I've seen up to 4.2kw going to export. When that died the warranty replacement was a newer HD Wave version that limits by power so sadly always capped at 3.68kw

You won't find a variable resistor anywhere near modern power electronics. The electronics switch the power on and off very fast (kHz, not Hz) and the amount of output power can be controlled by varying how long the power is switched on each cycle. Any feasible circuit will monitor both the voltage and current and both are used for feedback. You can go down a big rabbit hole if you want to know how it works. A quick google gave me this, not saying it's the best place to start but this will take you as deep as you like. It's a reference design for a 99% efficient hybrid inverter. https://www.ti.com/lit/ug/tiduf64c/tiduf64c.pdf?ts=1786346438488

I was thinking more at the electronic/component level. Just putting a huge, variable resistor in parallel to the load would limit the current available for export, or you could quickly switch the inverter output, or even the DC input at varying rates. I am just not sure which is the most effective.

Yeah, i'd have thought so too.

By controlling the inverter. To export more current the inverter has to boost the voltage target voltage higher and vice versa.

Having removed thousands of metres of ivy from all sorts of structures over the years I wouldn’t say this is the worst idea I’ve heard of. You will need a robust frame work as it can become very heavy. I have only seen building damage occur if the building was in a poor state to start or the ivy was left unchecked. for example poor pointing on brickwork, or the ivy getting under the gutter and behind the facia, I’ve seen thousands of pounds worth of damage in these instances. you would need to build into your life a yearly trim, this would need to be the entire face and would involve getting onto the flat roof and cutting back from the copings. i would want it cut with a 200-300 mm clear strip of blockwork showing below the parapet coping, allowing it to get under the coping could be disastrous. you could build in a metal flashing at this level as a boundary.

Weird I would have thought limiting by current would be easier to implement.

For these to work, there is a bit more to the equation. I can see how you are thinking about shear load transfer between the bottom of the post and the straddle stone, but what you show still acts as a pinned joint in terms of rotation between the bottom of the column and the top of the stone. . Unless the bending force is fully transferred by the dowel it's going to cause an over turning effect in the stone. A pin like this does not work. Also to resist this you need adequate soil lateral passive resistance, which I think you will struggle to achieve. And then we need to look at frost resistance ( the ground freezing and heaving) for example. It's up to you, if it heaves or moves then the risk is yours. Main thing is if it starts to fail that no one gets hurt and you don't damage the house. Technically you don't need ceiling ties if the roof is made stiff, like a big deep beam. This can be achieved by using say OSB / Ply / traditional timber sarking to the tops of the rafters. Lining the underside with ply makes it even stiffer. In the round we want to: 1/ Stop the front of the logia moving sideways parallel to the main house wall. We can do this by making the roof stiff and connecting it back to the main house wall so the main house wall resists the basic sideways shear, but also what we call complimentary shear. Here is quick diagram I copied from the internet. You can test this at home using a cardboard box with one side cut away. If you want to understand what's going on try it yourself for a bit of fun. Tape the box down to a table in different places and experiment, you can learn a huge amount about structural behaviour by just having a glass of wine and mucking about. 2/ The front of the logia moving away from the main house wall, perpendicular movement. The main thing here is to check the house can take these extra loads. Often you'll find that the external leaf, particularly masonry protests a lot if it is pulled outwards between the floor levels. I think the best thing, and most probably less hassle is to allow the house to carry half the vertical loads roof, they will be small as any snow, snow drift or snow falling off the main house roof will just slide of as the roof is steep. Normally we design for a roof access load, this get reduced when the roof is steep. Then look to see if it works along the front / sides Architecturally with a knee braces shown in red. The base of the columns would have some beefy 6.0mm thick or so fabricated brackets. The corner columns well attached to say 600 x 600 x 600 deep concrete pad foundations. I'll not explain here how / where the forces go in detail. But if you are thinking about laminating timbers up yourself it could be great fun to do and cost effective. The vaulting with no ceiling ties is attractive Architecturally to me. Try the cardboard box thing! if you can live with knee braces then it's a very efficient way of doing it. Let us know your thought on the braces. To add a bit. I like to design stuff using glue, but am always cautions that a builder may not follow my instructions. The previous drawing I posted is reasonably idiot proof as there are the nails as well. But I have some Client's, some are self builders who are really diligent. One in particular has built small boats so is experienced in gluing bits of timber together, they know to keep things clean and take care. If you're careful then you'll find that laminating up your own stuff, making joints is very satisfying. Glue works particularly well when in shear, we all know a good glued joint is often stronger than the wood itself.

If you were persuaded by Steve Koonin's views on climate change, but are open to the possibility there might be another side to the argument, you should watch Dave Bourlace's analysis of Koonin's points in his Just Have a Think podcast.

You really need to mouse-proof the house, not the cable, for all sorts of safety and health reasons, and sort out the current infestation ASAP if you've had mouse damage to new stuff within two days.

I am not sure how current gets limited.

What is slightly annoying is my inverter limits by power - which varies the amps as the voltage goes up and down. My voltage is regularly high 240's so i could export about 4kw but occasionally it dips to 230 or so which is only 3.6kw It would be nice if the inverter had a current limit export

I should have said export power - 16A export limit.

Yes. 8kw inverter 3.6kw export

What do I use when it's a cost thing? Aluplast Ideal 4000 (Double) Aluplast Idea 8000 (Triple) Alternatively I would look at Rehau, Gealan or Salamander.

Very easy to replace, obviously not as easy as glass into the frame without glue but it's a security thing as well. Doesn't take much longer to remove the glue, clean and put new unit in with the glue. It's also an extra, not standard.