MikeGrahamT21

I would say going through the wall will be fine. Circular holes are the best for structural integrity also.

22mm chipboard everytime for solidness, or if floor height is an issue like it was for me, 18mm OSB3, which will give the same effect.

Firstly, those holes are likely too close, as you've stated. I don't see how it could cause any issues myself, the weight of the chimney will be focussed on where the stack vanishes inside the masonry. Secondly, any chance of removing those air bricks and use those holes instead? Saves drilling If you are concerned, perhaps consider the roof tile vents instead.

Yeah absolutely, what I meant is I won't go out and blow £2000 before I know I definitely need it. Soon as the airtightness works are done, I'll leave a couple of windows on vent, book an air test, and if it shows its low enough, then proceed straight away. System design and spec has already been done from a few different suppliers, so I know what I'm buying, just a case of adding to the basket and hitting order.

Everything came from this place: https://pswtradesuppliers.co.uk/ I used 16mm MLCP as I found that products such as Hep2o, and JG, although having an oxygen barrier (very important in a CH system), they only seemed to be viable up to about 50C, which is no good for CH, hence why I chose to use 16mm pipe and the relevant euro cones, which I found very easy. More importantly, the eurocones actually fit inside the normal TRVs/Lockshields, so instantly become compatible with little outlay. Oxygen barrier is very important as it will protect your radiators from corrosion. I have a few radiators which are about 10m away from the manifold, and haven't noticed any issues without a pump, get a solid 2ltr/min flow on all of the rads when all are fully open.

My wet plaster is straight up on the blockwork, so there are no gaps for the tent effect. Ceilings have coving all round which is free of cracks, though there is always the concern that there could be a route through to the wall/ceiling joint, will have to see what shows up on an air test for this. Ive paid a lot of attention to round the windows and doors, and as I live in a bungalow, there is nothing to cover in between floors, and the loft isn't of concern as its a cold loft, which is currently ventilated, i've made sure any gaps between the living space and the loft are sealed, such as spot lights and wire entry points. Hopefully it works as planned anyway ? time will tell, but I won't be installing MVHR until there is a need for it, ascertained by an air test.

I finished the radiator system over a year ago now, its worked really well, definitely as well as I expected

I personally don’t see why it’s not achievable, a wet plaster finish is no different to an airtight membrane as long as it’s free of cracks, dot and dab would be the thing causing the problems. I may well find out through my retrofit that my assumption is wrong, but my instinct is that once there is a fan strapped to the door I’ll be able to resolve any minor leaks relatively easily. i also read a research paper done by Leeds met (IIRC) and they fitted mvhr to houses which had gaps filled and plywood over floorboards, final airtightness test came in around 12ACH and all of the houses had a reduction in energy usage, so I still think there’s worth even with poor airtightness test results.

Would you drop me the result on a PM at the time, as I will have totally forgotten about this in a few days, let alone a few months lol! My bungalow is a 1968, wet plastered with a couple of modern extensions, one of which is airtight, and the other which is dot and dab (which i'd sprayed copious amounts of airtight expanding foam behind the boards all round the perimeter). Floors are the main problem in this house, which i'm slowly working my way round.

Out of curiosity, to the bungalow owners, and previous bungalow owners, did you ever have an official measured air test performed? And if so, what did you achieve? I plan on having an air test done once all the improvements have been completed, and then take it from there, the dream is to have MVHR installed, and I suspect I will do even if the air test isn't so good, as I believe in the technology and what its going to do in terms of fresh air, and since I probably spend more than 90% of my life in here as I work from home, it may as well be as good as it can be.

As far as I'm aware, all 16mm MLCP pipe is the same, its classed as 16/2, which is a 16mm OD with 2mm wall thickness, so in that case the pipe should be able to be used for any of the fittings. As for the hybrid compression/press fittings which PSW sell, i've not come across these anywhere other than here, thats not to say they don't exist, i just only found them here, which is why i went with them. There is also a UK made 15mm MLCP made by Pegler, Tectite, which had push fittings like JG, but its around 4 times the price of the PSW stuff, I wasn't willing to pay the premium for 1mm less pipe diameter, and push fittings, I knew as soon as I tightened the first eurocone up i'd made the right choice with what i'd bought.

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