Nick Laslett

I find these websites are quite good for colour matching. https://www.colorxs.com/color/bs-18-b-29-blue https://www.e-paint.co.uk/colour-alternatives.asp?cRange=BS+4800/5252&cRef=18+B+29&cDescription=Raven

@Alan Ambrose, it is a very long time since I looked at this (2021), but I believe if you are on an STP, then all the house vent stacks can be on AAV. The STP has a vent to the outside. Mains drainage may have different requirement. I had my drainage design drawn up by Ingent Drainage. All the documents submitted to my BCO by my Architect show only AAVs, and when I had the first fix inspection, that is what he saw installed. Unlike a lot of my build, this is one area where my Architect handled the process, liaised with Ingent Drainage and presented me with a finished design. I had no input. I’m sure there is a much earlier discussion here about AAVs that corroborates the design I was given. https://www.bpfpipesgroup.com/media/73916/Air-admittance-valves-for-domestic-properties-v2-Jan-2024.pdf Some other links:

My windows are all sitting on the EPS cavity closer in the middle of the ICF block. The largest window is 2730mm x 1750mm. They are aluminium frames, with 190mm cills. 27mm thick double glazed units, weighing approx 25kg / m2. Thermohouse EPS is slightly denser than Nudura at 24 kg/m³ vs 21 kg/m³. For reference Marmox XPS shower formers have a density of 36 kg/m³. They have been in over 3 years and seem to be alright.

I’ve mentioned this before, but my ground floor UFH was installed with every pipe run being about 10m shorter than the loopCAD design, essentially missing at least one loop in each room. Unfortunately, even though I diligently took many photos of the install, I didn’t actually notice the shorter runs until many years after the foundation had been poured. One room is particularly bad. Don’t know what the installer was thinking. If you compare the picture to the design it makes no sense. Wrong loop pattern too. I was still very green at this stage of the build.

You have an STP, just use AAV for SVP stack.

I’m sure you are already on top of this, but my understanding is there are specific fire regs that dictate how you finish an attached garage. But I could be mistaken. So PB with 30 min fire rating is possibly required.

This is my best guess, but remember I’m just an amateur like you. What did the Structural engineer’s drawings specify? Their raft foundation design will be based on the structure that is being built and the ground conditions. They would have to incorporate the extra weight of the block and beam floor in the raft design, if that is what is specified. You can discuss this with your Structural Engineer, or talk directly with BCO. You are allowed to challenge your architect. Based on my very limited knowledge, I would be very surprised if you need a raft and block and beam, but I could be wrong. Others with more experience are sure to come along and comment. But not every post gets attention. Sounds like crossed wires, or lost in translation, or missing info. These two gentlemen @Gus Potter, @saveasteading are very knowledgeable, and much better qualified than me, and might happen on your post. Good luck.

Maybe I’m wrong, but isn’t water vapour lighter than air? ChatGPT, Gemini, and Grok all seem to think so? Science is not my strong point, so easily confused by these topics. I appreciate our A.I. Overlords can’t be trusted, but I do live in hope.

Here is some more material for anyone that is interested. A short paper by Zehnder comparing an ERV & HRV in the same house in Rotterdam over two consecutive 8 day periods during winter. Doesn’t seem particularly rigorous or compelling, but does confirm the humidity is 10% higher with ERV with colder weather. https://www.zehnder-systems.ch/fileadmin/user_upload/CH/HUB/Mythen_und_Legenden/the_effect_of_enthalpy_recovery_ventilation_on_the_residential_indoor_climate_-_aivc2014.pdf.pdf

Another useful source for why you might want to specify an Enthalpy exchange core. https://www.heatspaceandlight.com/whats-difference-between-mvhr-heat-exchanger-enthalpy-moisture/

I have the Zehnder enthalpy exchanger in my Q600 unit. This decision was based on my understanding that in a large volume house with low occupancy, there was potential for the air to get too dry. See thread linked below with post from @Dan F @lizzie changed her MVHR to an Enthalpy core, due to excessive dry air. Zehnder webinar, with is quite interesting, has Q&A at the end.

When I enquired with Paul Heat Recovery about the Zehnder ComfoClime, they actually recommended the ComfoPost as a better solution. They are both quite pricey, but the ComfoPost is a bit simpler and cheaper than the ComfoClime. General consensus here is that these solutions are not that effective at providing any real cooling. We have the ComfoPost, but it is not commissioned yet. I’m happy if it only takes 2°C off the room temps in summer. The ASHP is doing the heavy lifting in my cooling approach.

I wonder what wild life a steady supply of cooking grease would create in a warmish, sheltered vented space like this? You could develop quite an ecosystem after a few years. Makes me think of the warm water outflows at a Nuclear power station, and how it attracts massive amounts of marine life. Perhaps it is a situation to try and avoid.

I ordered my Newel Posts from Pears. Happy with the service and the quality of the product.

Here are the bookmarked threads I have on this topic. We have Suncool SN70/35 coated glass, which still lets in some heat. Visually on the inside it has no impact.

@Mattg4321, I did link to the iPad/iphone spectrum analysis tool I use earlier in this thread.

I’m sorry, I’m just an amateur. You’ve probably already seen this, but this is what Google Gemini says: For me, thinner paint and getting the pressure right had the biggest effect. Distance from surface and movement speed came next. I’d also heard about the “warming the paint technique”. Buy a different brand of paint, see if it is still a problem. I’ve only sprayed Benjamin Moore ceiling paint, Benjamin Moore Scuff-X Matt, and Valspar Premium Walls & Ceilings Matt. They all sprayed differently. I have a Graco sprayer, so I don’t know anything about Wagner sprayers. For ceilings I used FFLP514 spray tip. Google Gemini says this about tips:

Usually 70/30, but I tend to do a test batch.

@kentar, a lot of variables in airless spraying. I find this YouTube channel is a great source of information. https://www.youtube.com/@PaintHQ In my experience you need to thin the paint a lot more than you’d expect. Keep the spray gun, perpendicular to the surface. The spray nozzle sets particle size and fan angle, this has a big impact on the finish and distance needed from surface to prevent running and orange peel effect.

@Mr Blobby, talked about it in this thread. A couple of us used this product. This link is in the thread above, to a blog with video discussing the render reveal bead. https://www.beconstructiveltd.com/why-use-external-wall-insulation-reveal-bead/

Just a note for anyone looking at the BES flexible hoses for ASHP. Part Number: 25287, Manufacturer's Part Number: FH-500-28F https://www.bes.co.uk/flexible-hose-1-bsp-f-swivel-x-28mm-x-500mm-pair-25287/ For some reason they list them as having a 28mm bore, not sure why? This is just the outer bore, so how useful is that? On the manufacture’s spec sheet they are DN25, e.g. 25mm inner diameter. https://diversitech.global/storage/app/media/DataSheets/Technical Data Sheets/HOSES/H-FLEXIBLE HOSE-TDS.pdf They also have a DN32 flexible hose, this seems harder to find. Not really that important, but when I was getting the flexible hoses for my ASHP install, it was frustrating that the inner diameter information wasn’t easier to find.

Too much glycol?

The main issue my ground workers had, was very high water table, and sandy/gravely soil. The site is a former gravel pit. We have the same STP as @ProDave. They were worried about the unit popping out of the ground. They took the concrete from the back of the mixer into the digger bucket.

What kind of soil do you have? My ground workers first install attempt failed, when the hole collapsed. They abandoned that hole and started in another location. We needed expensive shuttering and bracing to support the install. Special attachment on the digger, rams the shutters into the ground.

I don’t believe you need the dual temperatures. Supply water just above the dew point and I expect you will get the house cool enough with UFH and Fancoils running at those temps. Plenty of anecdotal comments here about Fancoils delivering at temps above dew point. The trick is to never let the house overheat in the first place. The ASHP weather compensation will supply the cooling before the house ever gets really hot. You can use Home Assistant connected to a dew point sensor to control the Panasonic ASHP flow temp. @Dave Jones