Nickfromwales

Low surface temperature radiator / cover

50mm duct per single insulated pipe? Or a pair of hot and cold per duct?

Or never, eg if the concentrate of Glycol / other system treatment chemical is monitored and maintained ( as it should be regardless )?

Don't ( modern at least ) ASHP's shut down with low pressure warning like a boiler on a sealed system? Treating ( or slightly over-treating ) a system with Glycol seems fit and forget, tbh, and is near zero maintenance. Add the ASHP's own safety mechanisms on top of that and you need a doomsday event before this becomes a serious consideration.

I wouldn't use anything else!! You would just excavate down enough to cut and joint the pipe. UV? That's only e real world concern if the pipes are outside, but then they are already produced to be outside in direct sunlight....al-a every house you drive past which has waste pipes / soil pipes on the external facades. If there is a tray on top, zero damage or degradation can occur at the end of the day. You are, I'm afraid, worrying a little too much here. I still speak to people I have fitted bathrooms for, some over 17-18 years ago and some over 20 years ago ( before I had kids and my oldest is nearly 18 ) and they're still functioning perfectly well.

I only use 50mm on showers, and run 40mm to basins as far ( close to the basin ) as is practicable. I only reduce down to 32mm pretty much at the basin. 40mm works fine if you’ve got a decent fall, but the 50mm ( afaic ) is much better. I like insurance btw because I post here about jobs I do for others ( as I run an M&E company ) so I tend to go belt and 3 pairs of braces, but I’ve always gone the extra mile tbh, the reason I’m always busy I suppose!!

Yup. A 50mm pipe can run almost flat and still work perfectly due to the better air break internally, massively better than with a 40mm pipe. I recommend either swept bends ( vs elbows ) or 2x 45 degree bends to go around corners.

That’s the quickest route to get up and running, even if that goes on to borrowed time again. Then the immediate pressure will be off you, and we can work on a solution / investigation of what is actually causing this contamination. I’ve pulled out 20 year old systems with less crud in them tbh. Was the water that was flowing through that elbow ( in your pic ) potable water or primary heating water?

Looking good. I must get the last of my sh-office wrapped up this summer. The winter has been miserable, so was lacking in inspiration. Solar PV and my battery system going in next hopefully 🤞 as the shed / office roof gets a lot of sunshine on it, that and the attached gazebo roof. Deffo going to add cheap rockwool insulation in though, gets too cold or too warm. Will this be a man-cave or just storage?

I've done this more times I can remember. As long as you seal up with a frame sealant, and do NOT create a damp bridge with cement etc, you'll be fine. Yup. Take a look at a few of the houses around your area when driving about the place. They're commonplace. Horizontal needs a little thought, but vertical is pretty much safe as houses as long as it's not fitted opposite the fall, aka 'splodge' zone, of a discharging 110mm foul branch. Where the 50mm waste pipe ( I never use 40mm on subfloor shower installs ) exits the building and changes direction, fit a 50mm T and put a cleaning eye / rodding access cap so you can clean back to the trap, and downstream to the foul pipe with ease. Deffo 50mm for this instance

A bit like passing your hand quickly or slowly over a lit candle. One you wont feel, the other would burn your hand. I've just installed a similar system for a client, with UFH pipes set out at 120mm c's, and a 7kW ASHP. I fitted a low loss header with a manifold that services the whole ground floor from one central room stat. On the cusp of warranting a buffer, but zero space and the ( potential ) repercussions were not sufficient to warrant the upheaval of integrating one tbh. Current project sees a very different building with a main 2-storey dwelling, but with a few sporadic projecting single-storey 'wings', which will be 3 sides to the elements, so that one will deffo be having a minimum 200L buffer and probably 3 or 4 room stats to properly manage the differing characteristics of each of these spaces eg to maintain one ambient.

ASHP’s have been around for many decades. “Percentages” would tell even the most inept of individuals to remove their rose-tinted goggles and try actually performing the correct maths, eg so they were making a statement with 20/20 vision instead of one that would gain little or no credit. In the absence of that; Sunamps for half of one, the current offering less than 1/10 of one. Decades that is. The thing is still on trial. ASHP’s are not. UVC’s aren’t either. So :- Actual summery; Most grumbles of ASHP’s are from assholes fitting them incorrectly, or in instances that they were doomed to fail once unsuitability installed in. UVC’s, bombproof these days, it’s basically a stainless steel flask. Zero issues such as micro bore based heat exchangers…👎. Percentages? How many ASHP’s and UVC’s are currently in operation in the UK ( or the world for that matter ) ? Eh?🤔😉 How many SA’s by comparison? That equation will give readers of this forum an ACTUAL percentage to go on.

It was reference to using tape instead of traditional ‘scrim’ tape. Plaster goes over both options.

Reduced it by how much, if you don’t mind me asking?

Bonjour, as we say in Wales. Do you have a link to the item? There's a lot of other equipment needed to complete the installation, so buyer beware!!

I always did this, seemed a no brainer.

And if you ever want to change the LVT, with that down first then skirts, you have a real pig of a job on your hands downstream . And a lot of downstream trades / risk to the floor. I should have added that sorry. LVT / other floor covering ( as applicable ) into the voids where appliances go. Still pointless going under all the units and sending good money into the darkness never to be seen again. That money can go towards paying for the paint

If you make a mess of the paint spraying, you'll end up not saving anything as they ( the professional painters ) will have to rub that all back and make good. How confident ( competent ) do you feel you are with that? Painting, mist coat Kitchen goes in, less plinths and cornices LVT goes down, minimum amount only eg waste of time going under the units.

Quite low tbh, plus the cold bridging of all the joists / rafters. You can get through-wall AC units which are 'all-in-one', and may be more sympathetic to look at from the exterior / neighbours PoV etc.

If this is for space heating, forget the electric UFH as it’ll be quite crap under laminate for one, and eye-watering in terms of running costs. You’ll have to switch it on ages before going in to use the room too. Get a cheap A2A heat pump, something like THIS and it’ll give you heating in the winter PLUS cooling ( air con ) in the summer. The CoP should be around 3, so for every £1 of electric you buy, you’ll get £3 of heat energy output. It'll also be nigh-on instantaneous heating of the air, so no need for long warm-up periods before use. Electric UFH 👎. You will regret that choice I promise you. What is the level of insulation for walls, and roof? If not the heat pump, then do yourself a MASSIVE favour and fit electric convection wall heaters. You really need to be heating the air, not the floor. 11 OSB is very thin to go onto insulation btw., even with the laminate atop. . Point compression will be an issue, eg if you install furniture / floor standing racking shelving etc.

Just remember to turn the nut not the fitting, so the washer doesn't twist as you tighten

Yes, very claustrophobic at yours......... Get the correct part, you may just find it was twisted during fitting which would have been the beginning of the end for that flexi.

TBH, because it's not a Geberit, you may be better off using a far more reliable item, perhaps one of THESE. Better be safe than sorry

In your face @PeterW

God, I hate you some times Peter........