Nickfromwales

@TerryE You reminded me above you have HA. So will be simple for you to dial in some extra on / off prompts? You can dial in remotely from Greece lol. 😜

The primary issue @TerryE is the short duty of the pump as running for only a couple/few months max means these stagnate and ‘stick’ quite annoyingly. I had 3x UPM3’s do exactly this on a very high spec (£3.8m) PH+ project and I couldn’t work it out. Had to drive to West Sussex 3 times to get them all spinning again (manual strip down and spin with a pliers). Major unwanted cost to me, and a big piss me off!! Eventually I realised these pumps do NOT like sitting still. Solution there was a Shelley which was set to spin the pump for 60 seconds at 03:00 on the first day of each month. Had to use one per, to keep the switch lives apart. No issues since. Just so bloody much to think about with PH; pros / cons / caveats / gotcha’s etc. #livingandlearning

Conversely, I think this is where it shines!! You have hands and fingers, and a molecule of air will get through gaps you can't even think there is a gap, ergo you can't get everywhere so I would reconsider. You'll notice this a bit lol. Just give it time, and I'll wear you down .

https://www.dortechdirect.co.uk/catalog/product/view/id/3337.html?gad_source=1&gad_campaignid=17178602520&gbraid=0AAAAADt-Kn3UBXyOZR0vEG_JM_vZTmbQs&gclid=CjwKCAjw_-3GBhAYEiwAjh9fUK0DFMamvrz5o04Rdcyabesg7HS5_9qpOjUeEjy5SmbMj_yq1AzzWRoCY1wQAvD_BwE

I did as you ask in a house in Oxford, way back when first dabbling in the new works of building “not shit” houses; this was my first sample of an MBC PH dwelling. Client remit was to be able to have 4 reasonable showers at the same time, without notable dips in performance. Did it, and client was happy. Left is a 300L cold mains accumulator, and right is a 500L thermal store with a 28mm cold in / hot out instantaneous DHW coil (high flow / efficiency by design, courtesy of Telford bespoke offerings). Behind there is the utility room when I hid a 37kw Vaillant 637 system boiler, so when the TS called for heat it got it. This system literally can provide continuous DHW, but the caveat is that the accumulator will eventually deplete. I suggested a 500L acc’r but client said they’d see how the 300L one performed; no issues afaik.

Would still struggle methinks. It may ‘work’ but it won’t do as the op asks.

But you’ve failed to comment on how good it smells?

I like a challenge, but not one that requires 100% of my available life force. I wish you well on your renovation, and please keep us updated as you progress in accordance with your architects guidance. Are you aware of the retrofit / new build airtightness system from AeroBarrier? May be a good fit for you, to get into any missed nooks & crannies; that’s dependant on what stage you’re at.

I'm saying that the block can go, and the step can be reduced. Is there insulation under that small section of what appears to be a flat roof? Lots of info helps get better replies, so sorry if I'm assuming it does. Hard to tell from the pic what's actually in front of the 'step'.

Our pleasure, lol.

So in effect, a continually 'sucking' chimney that pulls freezing cold air through at a much higher rate of knots, by convection, all winter. I'd have thought that would be the opposite of energy efficient? All I do on a day-to-day basis is >95% PassivHaus standards and above. Current project is borderline EnerPHit refurb, so you've no fear of me 'not getting it' . BCO standards will be severely lower than EnerPHit standards, so I doubt you have anything resembling a hurdle to leap over in that respect; most BCO's simply gawp and quiz when they are on site, typically seeing the types of projects I do for a living for the very first time!! Great that they're inquisitive, terrifying that they do not know much at all about true energy efficient build methodology. My point being, you can invest this time and money on air tightness and reap much bigger rewards, vs microscopic boost on something which takes a huge amount of time / effort for very little measurable gain. Investing smartly in the correct way, for the maximum sensible reward, is actually the fundamental 'job description' . 6mm marmox boards over the tops of the joists, below the floorboards, would be easier and give far better uplift in the floor spec. The joints can be taped and the periphery foam sealed to the masonry with FM330 foam to significantly add to the airtightness of the floor, plus the XPS will be plenty good enough for killing off the repeat cold bridging. Your architects ideas are seemingly innovative, but in practicality are pretty dire. A permanently chilled chimney breast, over two stories, fed from a perpetual influx of damp cold air from outdoors to the under-floor void would be the opposite of my advice. The architect should be advising you to close these chimneys off 100%?!

None whatsoever. Done so many core holes through masonry I simply cannot remember the number!! Whether you choose to open the can of worms by asking the neighbours permission is up to you.... IIRC a 127mm diamond core drill leaves you a hole which allows the knuckle of the pipe fittings to set into the wall, so look to hire / buy at that size. Measure the fittings as some manufacturers have smaller knuckles, and some are much 'fatter', requiring bigger holes. Be sure to seal the external hole with sand/cement mortar, and the internal one with foam; if a cheap BM foam then do not let it ooze out into the cavity (less is more!!) and just seal a few inches in. You will need a 105mm hole high up too, as the space for the new loo will need extraction for B regs compliance.

I've installed loads of mirrors with it, with zero issue. Can't see why not, and it's less aggressive so doesn't react with things the way silicone seems to. Plus, CT1 can be painted whereas silicone cannot.

Get rid of that block kicker wall and replace in Marmox? That will give you height and insulation in one product, vs trying to insulate over a cold block. https://www.tilefixdirect.com/marmox-thermoblock-load-bearing-thermal-insulation-block-100mm-140mm-sizes/?sku=MXTHERM100&gad_source=1&gad_campaignid=20339692481&gbraid=0AAAAAD4kYe83bkF1nlWN7wup5I8-8mnFJ&gclid=CjwKCAjwuePGBhBZEiwAIGCVS1_y7lij0zE5CX-P_-XA50nzCox6eHe0feq1-MVu5MwkQvw0s9k_8xoCJxkQAvD_BwE

Is the floor heated?

A big subject, so I’ve started a unique thread for it.

Popular products for myself, are: Illbruck FM330 expanding foam. Airtight, closed cell, and goes off very hard compared to off the shelf foams from the BM’s etc. CT1 vs silicone, from a robot in cyberspace: The key difference is that CT1 is not a silicone; it's a proprietary TRIBRID® sealant and adhesive with a unique polymer formula, while silicone is a class of materials known for their flexibility, water resistance, and sealing properties. CT1 offers advantages over traditional silicones, such as superior strength and color retention, and the unique ability to be applied in wet conditions without shrinking or cracking, unlike many silicones. CT1 functions as an all-in-one product for sealing, bonding, and caulking, whereas silicone is primarily a sealant, with its strength and properties varying significantly depending on the specific formulation. CT1 Technology: Uses TRIBRID® Technology, a unique polymer that makes it stronger and more durable than traditional hybrid products. Application: Can be applied in wet conditions, even underwater. Features: No shrinkage or cracking. Excellent color retention (white stays white, clear stays clear). Solvent-free and food-safe. Bonds to many materials, including metals, glass, wood, and concrete. Can be painted after curing with water-based paints. Function: Functions as an all-in-one sealant, adhesive, and caulk. Silicone Composition: A material (polymer) known for its elasticity and water resistance. Application: Some silicones are not suitable for use in wet conditions or on wet surfaces during application. Features: Can have a long shelf life. Good for creating waterproof seals. Prone to shrinking, cracking, or degrading in certain environments, depending on the type. Can lose its color over time. Function: Primarily used as a sealant in applications like bathroom and shower enclosures.

Let’s discuss the different products and their correct placement / applications. Following on from this post:

They’re simply stating a knee jerk, uninformed, uneducated “builders” response. Stick to your guns and when built you can invite them around long after they’ve put their CH on, and you’ve not yet had to . Then they’ll soon revert to praising your methodology and saying “it’s the future” lol. 😜

It’s down to the finish of the reveal. You don’t really want CB on display, and some will use a fat bead of mastic to cover it. Theres fitters and then there’s fitters, but Norrsken tend to attract / employ the best from what I’ve seen to date.

I’d say do the cosmetic silicone via other after the external rain screens are 100% complete. A few folk employ a “mastic man” at that stage to do all the external mastic / frame sealant etc, and these folk eat / sleep / breath sealant and mastic so do a good job; essential this isn’t fecked up as it can’t be easily removed and reapplied. Like REALLY can’t.

If draining down, can you use a spanner? https://www.screwfix.com/p/tesla-expansion-vessel-service-valve-3-4-x-3-4-/442fj?ref=SFAppShare Fit one of these and then you’ll never have to drain down, for fault finding, and for routine annual inspections and checks. These are great gadgets, and should be commonplace imho.

On a current project, Norrsken fenestration, installed by Elite, the “silicone” I challenged. The fitters then pulled out tubes of high quality Sika mastic, and I pointed out that wasn’t silicone, but a brother of CT1. Very good stuff and this was used to create a fundamental weather seal around the outside of the frames, but which would live out of eyesight behind the external render system. @Selfbuildsarah, if you are hands off, then consider the merits of a completed installation, but first let us know what the cost is for “silicone”.

Irrespective, the in-built controller decides at what point the thermostatic control will say that it can or cannot accept further input. You don’t get to choose to ‘put energy in’, you just do so until it is satisfied. To ‘fill’ your thermino to 80° you just need to connect power to it and walk away. It’ll shut off when the thermister string feeds info back to the PCB to say it’s PCM (58) is heat saturated. The heat (input energy) is either by external source (which you have to govern its max temp) or by its own in built direct electric immersion element. It is this that decides the recovery time, the amount of heat input, and not any person. There isn’t any ability to be its boss, and decide what to ‘give it’, there’s just an inbuilt control which is satisfied or not. If not, it’ll ask for more heat energy, and you supply it or you don’t. If you don’t, it’ll simply go to bed hungry. One of the worst things ever, to try and give to a simple member of the public and try to explain the behaviour of a PCM based device. Ask me how I know.

Do you have posi joists? If so you can redirect the intake and exhaust, or just the intake, to be further away.