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Is this the winner for "Understatement Of The Year 2019"? ?

@JSHarris @Sensus I'm not an architect, and my physics could charitably be described as "hazy". But reading this it sounds like it might be one of those where you're both right, but @JSHarris is more right in practical terms? In my head an analogy might be if you wanted to stabilise the pressure in a pipe. You could connect a sealed air-filled expansion vessel. Or you could attach a water-filled reservoir. There are clearly measurable differences in the mass, density and compressibility of the air and the water (and, therefore, the amount of potential energy each vessel stores). But in practical terms, the size of the pipes to/from the vessels would also have a significant effect on the pressure-stabilisation characteristics of the system. A huge head of water up a narrow pipe would work less well than a small volume of air on a big pipe. I think? So it seems to me like the concept of "thermal mass" may be similar. Concrete may well be able to store a larger quantity of energy than timber. But (as I think @JSHarris is saying), the way the materials work to stabilise temperature gain and loss in a building is much more to do with how, and how fast, the materials absorb and release that energy than about their storage potential. And therefore the difference between timber frame and masonry may not be as significant as you'd imagine if you only consider their storage characteristics. If my cod physics has opened an unrelated can of worms feel free to ignore it ?

If someone supplies AND fits materials to a new build, they have to be charged to you zero rated.

& 100g of Whole Nut

Interesting responses @Russell griffiths and @PeterW, I thought there would be a bespoke item for such a situation so figured I'd ask rather than trawl looking for the unknown! It appears that I need to McGyver the s**t out of it. Not an issue, both suggestions are good and give me something to ponder. Thanks

Not sure I'd ever voluntarily connect anything to the Evil Empire, either. It's becoming increasingly clear that Google is at least as evil as Facebook, Microsoft et al, in terms of abuse of personal data.

@TerryE, you'd be the first to tell me to KISS

I recall the 15% rates. Over HALF my take home pay went on the mortgage, leaving me less than £500 per month to survive on. There were no luxuries, no going out. People today say how well we had it buying our first houses for so little, but I can't see many putting up with all the "going without" we had to do to survive those first few years. About all that saved it, was high inflation, and a salary that kept up with that high inflation, which had the effect of fairly rapidly deflating the debt in real terms, but it was still a few years before you could start to relax a bit.

Excellent point. (Didn't want to burn my ar5e though! ?)

Need to shut the lid or sit on it to reduce the ability for air to go everywhere ...

All in, glued and ready to test: As last night's beef shatkora etc "went through the system" earlier I needed a source of "odour" and got to thinking of smoke pellets my old man used to get at BG. In the absence of any I had to get inventive. Thus a foil tray from a mini quiche was pressed into service (with added foil when I realised it had holes in). A garden test confirmed a rubber glove as a good source of some nice, acrid and more importantly thick black smoke. With one kid on camera and a second ready to switch on the fan I set fire to the glove. As the video shows, I'm not confident Is this in the fail (phall ) / shouldn't have bothered category? Or is it that the smells it's meant to extract will act differently to smoke?

I used to worry about PIR lights triggering falsely in the days of a 500W halogen tube. Now with a 5W LED I don't mind if the cat sets it off. I tend to buy a light fitting with the sensor built in. That gets you a light that looks right and gives the required light but usually you don't get the choice of what type of sensor it has.

Looks good though, be interesting to see how well it works. Probably needs a good dietary challenge...

It may well be that the tractor lights are higher up than a car, and as they are a source of moving heat the PIR senses them and switches on. One fix might be to try and turn the sensitivity down on the PIR, so it only responds to the movement of nearby heat sources. Unfortunately a microwave Doppler sensor won't get around this problem, as I have one set up part way down our drive as a trigger to start the CCTV recording, and whilst that's generally a great deal more reliable than the built-in motion detection in the cameras, it will get triggered by a large truck driving along the adjacent lane (not something that happens very often, though)

We have lots around the house, for much the reasons you've outline, @AnonymousBosch. The one in the utility room above the back door is brilliant, as the lights come on when you walk in with arms loaded with shopping, washing etc. There are two types, passive infra red (PIR) and microwave Doppler (sometimes called radar). Initially I had a PIR one by the back door (one of these: https://www.tlc-direct.co.uk/Products/TLPIRFL.html but we had problems with it false triggering from shadows through the window in the back door, so I replaced it with one of these Doppler ones: https://www.danlers.co.uk/microwave-presence-detection-switches/mwcefl-ceiling-flush-mounted Elsewhere we have the PIR switches and they mainly work OK, with just a very occasional false trigger. I fitted them in the WC, various cupboards, our under eaves loft space, the services room and our walk-in wardrobe. The advantages of PIR are that it mainly responds to changes in warmth, so reliably detects people and animals. The disadvantage is that they also detect warm air movement, so, for example, our walk-in wardrobe light will often come on when the bathroom door is opened, as the rush of warmer air coming in under the door to the wardrobe is detected. The advantages of the microwave Doppler switches is that they only sense movement of solid objects, so they aren't triggered by warm air movement or shadows. The snag is that they can sense through walls and doors, so movement outside a room, close to a wall or door, may be detected and turn the light on

I deal with this by an outside PIR triggered light that comes on as you approach the front door. That illuminated the keyhole (you WILL have to put something down if carrying, to unlock the door) Once unlocked you open the door, turn an inside light on and pick up your stuff. Why make it more complicated? Our unload shopping routine is usually carry it all to the front door and place it just inside the door. Then when all there, go inside, wipe feet, change to indoor footwear and carry shopping to kitchen. This avoids keep walking in with wet feet etc.

You can buy a standard 10” filter that does that already. https://www.wiltec.de/nw-790-g-siliphos-cartridge-silicate-phosphate-binder.html

Pretty much, yes. Our boiling water tap came with a phosphate dosing unit, that was just a replaceable cartridge filter that contained phosphate balls. Probably worth an experiment to see if just sticking some of these balls inside a clear water filter housing would work. Might be an idea to plumb a ball valve bypass around it, so that the flow rate over the balls could be adjusted, as it might work better, or use less phosphate, if the flow over the balls is adjusted to be just enough to stop limescale sticking to stuff.

Now the wife and I both have degrees in electronic engineering, both physics and maths fans and, sadly, none of this has rubbed off on our children who are as addicted to snapchat as the rest of them. However if I were to suggest a similar empirical experiment to settle an argument such as the one above, very quickly we would be moving to a separate investigation on how long it takes for a cup of tea to evaporate from a human sized form:) BTW, I'm with you on units - when I did A Level physics many moons ago, the first thing we learned were SI units, and manipulation of unit nomenclature. Our physics teacher rightly pointed out that if you got stuck in a test and couldn't remember the exact formula, quite often you could figure out the bones of it by looking at the units provided and the units required for the answer. Also, I noted this from helping the kids with their homework this week - Without units, science wouldn’t make sense. Units allow us to use numbers to describe the world. That’s why maths is called the language of science. Understanding units and using them correctly can make all the difference in the exams. You want to nail those maths-heavy questions in your GCSE Physics papers? Then you need to be at one with your units.

All Hoovered up so I can stay in the loft now! Black, vertical 32mm, coming up through the ceiling will go to the right, under the grey soil. Means lifting the soil a tad and remaking my carefully crafted wooden cradles that support the soil at the mo! Not much room between top of ceiling joists and u/s of the grey soil: 32mm soil will then continue parallel with grey soil into the white, 100mm extension at the end. I'm not going use saddles so as to keep the height down going under the soil: @JSHarris, the elbow inside the duct, how much should I project by with a short bit of pipe? Cheers

I remember my first mortgage. The bank said you can borrow 50k but in 25 years you will have repaid 150k. Holy S*+t I thought. Every penny went into paying it off early..

There is a saying that the milk should never, ever, touch the tea before the water. Not sure how that is going to help decide between construction methods, but I find that tea helps the thought process no end.

Pretty much a spot on assessment, in everyday terms, IMHO. Adding material that has lots of heat capacity, be it specific heat capacity or volumetric heat capacity that's used to define it, may or may not have an impact on the thermal inertia of the building. As an example, lets roughly compare two types of floor construction, a beam and block floor, with insulation above the concrete, and a passive concrete slab floor, with insulation beneath the concrete. The concrete in the beams and blocks will have a significant heat capacity, so will be able to store a fair amount of heat for a given absolute temperature. However, because the insulation layer will be above this concrete, the rate at which heat can flow into, or out of this concrete to the inside of the house, so changing the amount of heat stored in the underlying concrete, will be small, so that heat capacity will have very little effect on stabilising the temperature of the house. On the other hand, a passive concrete slab, which may well have a very similar amount of concrete as a beam and block floor, and so much the same heat capacity, will behave very differently. The concrete has a reasonably high thermal conductivity, so will be able to absorb heat from the house, and emit heat back into the house, as the house temperature varies. The rate of heat transfer will be fairly rapid, so such a concrete floor will be a useful aid to helping to stabilise the temperature in the house, and increase its thermal inertia. Both these houses will have roughly the same mass of concrete in the floor, so both will have roughly the same floor heat capacity, but in one that heat capacity will be useful in helping to increase thermal inertia inside the house, in the other it will have little effect.

There are loads of examples, one that narked me the other day was Caroline Lucas MP talking about "wellbeing", if she wants to be taken seriously by the world, stop using wooly, meaningless and unmeasurable terms. She said another word that had no meaning, but I can only remember my dispair and anger.

That was my strategy too. It’s amazing how quickly a mortgage repays if you start overpaying. I was mortgage free in my early 40s and then saved enough to do the self build from equity and savings so still mortgage free.

I doubt it will make much difference, TBH. If you want it to work a little better, and have slightly lower flow resistance, add a short length of pipe to the elbow, projecting up the duct a bit. If you look at the flow resistance caused by a typical extract grille it's probably a lot higher than this thing.

I have fitted Combimates in new builds. Quick to install and they don't take up much room. The only issue is if you leave them with the phosphate balls and don't use any water the stuff breaks down and you risk clogging the system. You can take them out if you plan to be away for over a month.

Harveys make the TwinTec as well as the MiniMax and Crown.

No, in our case we have 250mm (2x100mm = 1x50mm) this was because the slab designer was worried about some of loads in the middle of the slab and after they did the sums they chose 250 rather than pockets down to 100 in all places where the loads were.

Too large to maintain temperature stability. Good question, look forward to the answers

Out of interest, what units do you use to measure "thermal mass", to enable one form of construction to be assessed against another as having more, or less, of it?

I'm at stage where I've had just one drawndown, but it felt like part of my soul was going away. Hope to overpay as much as possible and be mortgage free by the time I'm in my late forties.

HS2....

What will be completed first - Brexit or the bathroom?

Interesting question, looking forward to hearing about it......... being a serial foam abuser !

is the bathroom actually totally finished?

I just have to add this ?

No problems with creaks or groans from a timber frame or the plumbing. UFH works best at a low temperature for a long time, rather than a high temperature for a short time.

With close coupled check the seat will stay up.

nice and flat.

I just got 4 new tyres from Costco. £80 off a set of 4 or £40 off 2, and the price was decent for CrossClimates (£464 including fitting).

Guttering complete, scaffolding away, MVHR complete. photos!

Timber frame being as it is (a bit more 'moveable') our Architect noted it's typically problematic to have first+ floor underfloor heating since movement can break pipes etc. Has anyone tried UFH on timberframe? Bad idea? Can be done?