Nickfromwales

Doesn't really seem a suitable product for a floating floor, unless the floor is otherwise supported and the insulation is just there to insulate. Seems PIR is the way to go here? It's also not water proof / resistant, so the DPM would need to be hugely robust. Says it has a 2% shrink ratio too, so tight fitting boards will eventually become loose (if wedged in-between joists for eg) so seems the cons outweigh the pros here.

I think you'll need to reassess after 12 months of 'settlement'. The build was done during the "wet" season I assume, and the fabric of the build heavily soaked and then all of that moisture got locked in by the render. The different rates at which all this would dry out would be significant, so I would fill these cracks with a good quality paint and monitor every 3 months. Staring at this every day will put you in an early grave, so, relax, as the house isn't going to fall over any time soon, and monitor as above. Tapping on the mortar will reveal if it is going 'hollow' (has separated from the structure) which would be more of an issue. Answers for this problem will not be coming any time soon, well not ones worth hearing at this time anyways. Time will tell, I'm afraid. In the meantime, go about your daily business and stop staring at these cracks is my honest advice.

The exact reason that on my current project (a fully certified Passivhaus) I am designing this issue out; manipulation of where flow goes first, selecting which pipes get insulated before reaching their target 'zones' and also by selecting different o/c's in different spaces according to discipline. One thermostat planned per floor but with a very tight hysteresis so the second there is fluctuation (up or down) the systems can respond quickly (as quickly as a PH can) and mitigate against over / under shoot. Solar gain over shoot is the offender that my efforts will be largely focussed on, heating is a doddle to deal with.

Ah, shit. Not another typo!? Have you been out in the sun with no hat on?

I think you meant "loses". Just saying ✌️

Speak to CVC Systems directly and they’ll sort you out with whatever ventilation products you need. I buy all of the systems I install for my self build clients through them. Great guys, and great service / products.

I would expect them to be exaggerated tbh. What are your specific concerns?

I doubt that will be of actual value tbh. No different visiting a showroom / manufacturing base here. They'll all make the same promises, just one will have cost you a few hundred or thousands to hear.

Why, might I ask?

I'm afraid not. The £2m dollar question is HOW?

👆

It's a load of nonsense tbh as the FR rated stuff is bloody flammable! You're not supposed to use it where a gap exceeds 6mm or something daft.

If so, then you defo need to get the builders to correct this!! You should be able to disassemble everything 'user' and have no bloody leaks WHATSOEVER.

Yes, probably selected due to the heat in the flow and return pipework

Knock the concrete blocks out and replace with an EPS based system? I am not sure of the centres of the insulation based B&B systems so would need a survey for feasibility, but getting rid of the blocks would be a huge leap forwards. Have a look at BeamShield. When installing these types of 'floating' floors (like in a garage conversion) I always install 2 layers of 22mm P5 deck, glued and screwed and laid perpendicular to each other. Takes a washing machine on spin without blinking. One layer will be poor tbh.

@nod ?

Hi. Brick and block or ICF / other?

Only required if 2 differing RCD's are employed pre-CU? I've only ever installed an 80a switch-fuse at the meter when conveying tails of 3+m and above, and this is never a problem (no RCD required for the last few) but I'm not over the 18th edition like a rash tbh. If run in SWA there should be no requirement for RCD, but it may be requisite where the tails are sub 50mm from surface. You can screw into a live tail and make the fixing live, but with a SWA you'd have to short live to steel armour, so the tails need to be further away from 'attack' and the SWA less so.

You can get down to much lower speeds overnight. Possibly on a timer which diverts to a second controller. One very good 'box' attenuator may sort this, and I have NEVER installed an MVHR system without either 500mm long ones or 1000mm where I thought the job would benefit / there could be any chance of this type of issue.

It (requirement for defrosting cycle(s)) becomes prevalent when the ASHP is being asked to do things it doesn't like doing, and even more so when it's 'least best' to do so. The ASHP's I've fitted recently should literally almost never freeze. Retro-fit units into 1930's refurbishments will likely be defrosting a LOT, ergo I would never install an ASHP to such a property, (but where others would of course). Low flow temps and strategizing when (and how) to heat DHW will all add to the SCoP and longevity of the equipment.

This is a huge bone of contention. If an ASHP has been spec'd to go into a dwelling that sympathises with such a unit, then freezing should be deleted? If it's Baltic outside and humid, ergo defrosting is prevalent, then the owner should be heating the DHW by the immersion(s) for that period of the year. The maths defo work out, as I've stated recently, just with the huge labouring of the HP being eradicated, plus the extension to the longevity of the HP / ancillary equipment. If you have solar PV then you will be banking electricity tokens all summer to 'spend' on this pursuit, but at the time where this will be most problematic your CoP will be 2:1 if you're lucky, and much much worse if defrosting is repeatedly required and added to the maths. In the arse of winter I recommend that you heat DHW via a cheap rate electricity period via the cylinder immersion and only do the daytime heavy lifting at most eg maintaining the absolute lowest set point of say 50oC. I have been oversizing UVC's for years now, for exactly this reason. Bulk heavy lifting when the CoP has the advantage, and boosting up the temps (heat energy capacity) via the immersion to stay away from having to do this whilst low temp heat is being produced. The oversize also helps massively during summer where extra DHW can be stuffed into the same device (by "overheating" the UVC with 'free' energy).

Nope. The post refers to shoulder months where the heating may not be needed during the day, but instead where solar gain becomes problematic for E > S sunshine in the morning, with the S > W and N rooms then waiting to get the heat and balance out the slab / room temps. If the house calls for heat the HP will be fired by the heating controls, as will the manifold pump(s). With my preferred technique of running the manifold(s) pump(s) during sunlight hours the problem of each far side of the dwelling behaving differently, heat wise, is reduced significantly.

One pasty too many for lunch?

Nope, it was just down to it being a baaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaah'd design.