MikeGrahamT21

I think a dehumidifier is going to be your best option here, dessicant ones from Meaco also give out heat as a waste product, which is useful in winter, and you can leave them on 24/7 as they will come on and off as needed based on the RH setting. Be warned though, they aren't cheap to run, but you will likely draw many litres of water out of the air, and fabric of the building which will help greatly. This will of course only mask the problem, you then need to come to a consensus as to what the problem actually is (poor insulation, rising damp, penetrating damp) and work on a more permanent fix.

I got mine from here: https://pswtradesuppliers.co.uk/ Prices seemed reasonable, and I liked the fact that they manufacturered their own pipe, plus the hybrid of compression and press fit connections really appealed to me, as the press fit tools are very expensive. I think there are quite a few out there like this. Its been in over a year, and no issues so far.

I always use these for insulation https://www.secondsandco.co.uk/ You'll be able to get phenolic boards probably cheaper than the PIR you've got a price for, and they're always in good condition i've found

Plumbers always suggest copper, as its what they are most comfortable with generally. MLCP (and I'm talking the proper Pex-Al-Pex stuff) is a hybrid between copper and plastic, has all the benefits of both, and the aforementioned pipe has an aluminium liner down the middle of it, as an air barrier and pipe stabiliser/strengthener. One of the things about going down the manifold route is the lack of joints in the system, which doesn't only make it much quieter, it also stops any potential leaks from happening. Aside from that MLCP will also be much cheaper if you use the 16mm stuff from europe with the relevant cones everywhere, and far easier to install. I ditched the copper when I re-did all the pipework here and have never looked back since.

Yes VCL on the warm side. You could certainly tape the insulation boards with foil tape, I did the same on my latest vaulted ceiling, however you have to look carefully over the whole surface of the boards and ensure any nicks or imperfections are taped over too, if your boards are a bit beaten up, may be worth just using expanding foam in any gaps and then an AVCL over the top held in place by your battens.

House looks stunning, great job!

I got mine from here: https://www.toolden.co.uk/accessories/adhesives-sealants/expanding-foam/illbruck-fm330-pro-foam-air-seal/ I know when i was looking for foam, I noticed that the FM330 was the only foam I could find which had been tested to both + and - 1000Pa and achieved <0.1m3/(h.m) which i thought had to be a good thing, unless they are the only ones who note it down like this.

I read an article recently about a new module which is coming in, not mandatory yet, but looked really good: As with most things though, they are rediculously expensive, a full CU will set you back over £1000. They are type B RCBO modules, priced on average around £250 per module! But will give you ultimate protection. Sure prices will come down when they become mandatory, as they will, probably in 19th edition

These are the 3G ones i've got, though they're even better now than when I got mine: https://www.sterlingbuild.co.uk/product/eco-white-pvc-triple-glazed-roof-window-bundle-with-insulation-collar-and-underfelt-collar They are actually OKPOL, a polish window manufacturer, and really good. 0.83Uw for that price is brilliant. Mine was 1.0U when I bought, they've made a few improvements since including using Krypton gas now. The Neo Air vents tend to be a bit leaky, but you can buy a Vent Blank plate which seals it off from a company called Sunlux for £50 each, which I did as soon as I realised how leaky they were. Rest of the window seems airtight as far as I can tell. Would recommend them though, a bit fiddlier to fix than Velux, but I guess you are paying for ease of install with those.

Its like a totally different product compared with normal low expansion foam, doesn't set completely hard, and remains very flexible with a high bond strength to the substrates. You discover just how strong when you try and remove it from somewhere you didn't want it to be. Normal expansion foam isn't airtight, and you tend to get a micro crack in the bond at some point.

FM330 is brilliant stuff!

UFH won't get hot enough to kill bacteria, unless its a combined system with your wall hung rads?

Yeah each radiator would have its own dedicated flow and return, otherwise theres not much point in having a manifold. No special components, just your pipe of choice, insulation, lockshield and TRV ? and a lot of patience if you aren't ripping all your floors up.

Plastic will give you the most problems in terms of expansion, PEX-AL-PEX (MLCP) would be the best option for burying

Cook your lunch first, and then make a cuppa afterwards ? Agreed though, going to be a long time before battery tech will be going in my house, if ever, if current electric prices prevail.

Its a 10year warranty, ATAG boiler, well built thing I must admit, its insides look like they are designed to be permanently on show, almost makes me want to get some perspex and cut a whole in the cover! Almost... The last boiler was one of the terrible Ideal Isar HE24's, and that lasted 10 years almost to the day, but only had a 1year warranty, got more from it than we ever thought.

No fun ?

lol, sorry, I thought the same when I wrote it. Maybe heat storage capacity is a better phrase? ?

I find a lot of new tech these days tends to even outperform the calculations which is quite nice, I suspect people have learnt from the years of mis-selling. I plan on my current gas boiler being the last I ever have, but its only just over a year old, so hoping also it lasts a very long time!

If the PIR is on the inside it will lower the temperature of the masonry and make it more likely to suffer from condensation, which could lead to serious structural issues if left unchecked. IWI tends to come with detailing for a vapour control membrane, but even then if it ever gets damaged, you could end up in trouble. Its all about the dew point within the structure, IWI moves the dew point further inside, EWI moves it further out. If you have PIR in the cavity I would imagine IWI is probably not a good idea, and EWI would be pointless since cavity PIR always comes with a cavity gap. Most people opt for EWI as you can also then use the masonry as thermal mass to help balance temperatures across the year. Sand/Cement render is very old school, thin coat render systems are very good at their jobs and if applied correctly they will last a long time, much longer than sand/cement render.

Ducts definitely need insulating, or burying under the insulation in the loft. I think the manifolds have a small amount of insulation in them for acoustic purposes, but not sure how much it provides for heat insulation. I suspect if you can build a box and insulate it around the manifold, this would probably be the best option for minimal heat loss, this is what I plan to do, just becomes a bit of a pain taking it all back out in order to do any cleaning

I dont think it would matter either way, it'll be virtually the same temp. Almost zero heat input from interior of the house, some roof membrane and tiles isn't going to hold the temperature that much higher than external.

Yes you do need a lot of them, but maybe not as many as you think, and it doesn't take long, but its worth it to do a proper job. And the load they suggest is more to do with the ceiling joists than the loft legs themselves, its called covering their backs. I have loft boards up there, which are a quarter the size of full sheets, and there still wasn't that many legs for the area. You talk about the loft as being somewhat warmer than outside...when you've packed all that insulation in, it'll be virtually the same temp as outside, as thats kind of the point in doing it.

I think they can be a weak element, from an airtight perspective, but I think the angle of the glass has something to do with it as well. Maybe a more important thing is that they are well balanced in terms of energy value, as they let potentially more energy in than they let out. In terms of pure glazing value, compared to a normal window, they are a weaker element, hence why we are seeing 4G and even now a 5G from Velux. I have some older 2G (probably around 2.0U) Velux, and newer 3G (1.0U) Okpol windows, and the difference is immense. All south facing, but the frost stays on the 3G for considerably longer than the 2G. Also measured glazing temperature in the summer, the 2G can be 20C higher than the 3G panes. Quick measure on temps now, with outside around 5C, the 2G panes show up at 17.7C internally, 3G panes at 19.4C and the internal room temps are at 19.9C

Kingspan use purlins as its required for structural purposes. Oh and you'll probably find that they use insulated panels which sit on top of the purlins, and screw down onto them, i.e. removing the thermal bridge.