Nickfromwales

No problem at all. There are benefits to be had with going with our advice here, some which are not immediately obvious but soon become apparent after opening a dialogue here for experts in their industry to bolster each decision you then go on to invest time and money into, safe in the knowledge that…. ……in the winter you can use them to keep your hands warm 🤣.

God dam-nit. Have you been speaking to my wife?

Amen reverend. 🍻

Obvs should have caveated by saying don’t hang an 80” TV off one fixing lol. 200mm concrete screw for anything crazy. Happy days.

You know to approach Trevor @ cylinders2go for any cylinders, ya?

Easily! You can also rebate the insulation to fit plywood across multiples of them if you were looking to affix between or away from the flanges (where the fixing holes simply don't line up for eg). Exp foam behind the plywood and then fix that to the flanges, leave to cure for 24hrs, then crack on with plaster boarding. Much more flexibility if you make the plywood patch a lot bigger, so when the rooms finished and you think the TV's too high / low etc you have room to manoeuvre

It's staggering just how shite some trades' workmanship and standards are... They just think because they've sweated for the day that it's a good days graft. Good on you for sticking to this and getting the simple measures done to make a job well done, would have been so much easier if they had just given a feck..

Yup +1. Defo need to have those de-rated to say 60a per run vs just isolated x4. Can be the same device, just knock a way out for a 63a MCB in each one, and then you have a switch-fuse isolator. Is this a very big property, eg to warrant 4 CU's?

It's down to the manufacturers installation instructions (MI's), recommendations and guidelines, eg is the moisture thing mentioned in respect of their longevity, and therefore may affect the warranty of the product if you 'stray' away from the MI's? What if the water gets in and then freezes etc?

Who has calculated the condensation risk, and do you have panels which have drainage points to collect and manage the condensate? I would be very cautious about putting the same temp cold (defo not cooled) water through the system that heats the ceilings.... Do you have a design or specification that states the product can cool via these panels? Any product link / info you can post?

Hi. Why go for the expense of SIP's when you could just stick build this with a local builder for less money and far more flexibility? That just seems way OTT imho. Very easy to get this to a similar, or better standard, without the bespoke costs and difficulty in joining these things up / together. There's very little point getting this to a much higher standard then the building it is being joined to, so you may want to rethink and save some money and grief here. A local builder would fly this up, even timber frame with a brick façade, and they'd need very little input from a designer. Does the 40cm mean you would have to step up into this extension, or would that still leave you with a level threshold internally? Any new works that close to the tree will anger the rules & regulations gods, to SE will prob say rip out the existing and start afresh, which is absolutely what I would do vs throwing good money after bad. FWIW I would avoid a ventilated wooden suspended floor like the plague, and instead go for a nice, solid, well-insulated slab

The start and finish points are relatively easy to fix and lock in, it's the deflection along the run that needs a bit of thought, especially as you'll be bumping into these, stepping over, and accidentally kicking them and what not. Depending on ground conditions, in the past I have just sharpened a bit of 2x1 (4-500mm long) and then put a 100mm cross piece on top to make a T shaped chair and then simply smacked these into the ground at diminishing heights for the fall, say 8-900mm apart. Use a string line from invert to invert as a guide and then hammer these into the ground to suit. Lay the pipe on top and lash it down to these chairs so they cant move about. Job done. Have the 1st fitting and the last fitting in place, and go point to point with the string and then chairs. BCO will want to see rest bends with concrete wellies, as per bb regs, same with chambers, but also good to concrete pad around any changes in direction. FYI, you should not have any changes in direction underground where there are any form of solids, unless you can rod from both direction to that change point. I'd say to use the long 5-6m lengths to avoid joints, but whatever you find easiest tbh. Don't fear using joints, these things are piss-easy to make off, and are bombproof when underground (that's where they're designed to be forever at the end of the day).

8.1 kw in a decent home with MVHR is BIG..... you may find it gets you a bit too toasty Is that 8.1 kw to the room?

Why are we using arse-tificial non intelligence people? It just surmises general crap on da web and dishes it up for you, utterly random and completely unreliable / non-robust.

It’s the only trap you can use for discharge as water isn’t ever routinely flowing through it; ergo a wet trap would run dry (evaporation) and fill the room with stench. note: This post was not generated by AI, I used WI instead 🏴󠁧󠁢󠁷󠁬󠁳󠁿.

I call it “aye,aye”. None of you lot seen the film iRobot? The end is nigh.

Rebar and concrete pads? Will need something regardless to hold these in place robustly whilst working the insulation into place around these.

Yup. This just stops things moving around, but as @nod says, when the screed hits it that’s the end of your ‘worries’. Membrane needed atop for liquid screed obvs.

Seems odd that the above bulletpoints don’t use standard terminology? Pipework for tundish connection are referred to as D1 and D2, D1 from PRV to tundish, and D2 from tundish to ground outside or internal waterless trap etc. @MikeSharp01 Do you have a 110mm foul drain in the plant? I usually come off this with a reducer to 40 or 32mm waste pipe, (I don’t think any modern waste pipe cannot take high temp water these days, but that’s the only thing to check / catch you out), and then terminate the waste pipe work with a waterless trap (preferably mounted vertically). Into that goes the D2 from the tundish, (T&PRV from the UVC), and for belt & braces I would install a second waterless trap for the other D1 discharge; the 6bar PRV from the UVC control group and PRedV. Most fitters will tee these two 15mm D1’s together into one 15mm D1 and then go into one tundish, but that requires the D1 and D2 installation recommendations to be followed to the letter. For eg, if you don’t have min 300mm of vertical D1 arriving downwards at the inlet of the tundish then the water will still be trying to ‘turn’ and not just fire straight down, ergo some of the water will splash out of the tundish; this is only real-world problematic where the T&PRV or control group PRV have opened fully, vs are just dribbling, but I test for worst case because you can bet your arse that if you don’t it’ll come back and bite you. *If the waterless trap has at least 300mm of vertical pipe dropping out of it, before it turns horizontal, and the exiting waste pipe is low to the ground, AND you have at least 300mm of pipe (more is better) between the sum of the 2x 15mm D1’s teed together before that combined discharge arrives at the inlet of the tundish, then you can go with one waterless trap. Depends on the space / pipework / feasibility etc but usually doable, but this is often decided by the height of the control group (whether these can be teed together as high as possible and still have a min 300mm fall before connecting to the tundish. FWIW, if I am struggling and have to tee the 2x 15mm D1 PRV’s together then I marry them with a 22x15x15 tee and then have a 22mm pipe going as the ‘combined’ D1 into a 22mm(in) x 28mm(out) tundish (instead of of the usual factory-supplied 15mm x 22mm unit (which then gets discarded)). If you get a bit of 28mm copper out of the bottom of the tundish and have a 32mm compression waterless traps, that will tighten down onto 28mm copper. *If not, fit 2x tundish and 2x waterless traps. It’s not much more money or time tbh. These are the kind of things that get lip service only btw, until there’s a problem and then whilst functioning you then realise these aren’t capable of getting the discharging water out without causing a bit of localised splashing / flooding. The above pic is from Hotuns site, but I really doubt the longevity of their waterless tundish offerings which have the non-return arrangement. Note that the above pic shows the tundish as the only air break stopping stench from the stack getting into the house. I’ve used these once and was not overly impressed tbh, as the guts and spring / plunger just seem ‘feeble’, so won’t use again. Tundish and proper waterless trap every time for me!

Yup. Just needs the ‘right amount of attention’ and then go CRAZY on air tightness. You could have 1000mm of insulation in the walls / roof but still have a cold house in winter if the infiltration is high. If someone competent says they can whack the sub base very near to ‘flat and level’, meaning you only need to put just the minimum thickness (<20mm) sand blinding down, then replacing the 25mm deficit with EPS would always be my choice. That’s better than someone importing and laying a full 50mm sand blinding layer down, which is cold, and is only doing only one job. Cheaper and easier to throw some 8x4’s of EPS in there, and then the primary DPM, (you can choose to the do another thinner ‘secondary’ membrane further up in the insulation layer and start your fundamental AT mitigations there).

I’m just not a fan of putting the ‘fragile’ membrane down on terra firma so makes sense to me to split the lower layer of insulation 25/75 and put the membrane ‘out of harms reach’ so to speak. If any sharps etc stab into the underlying EPS then that’s of zero consequence. 25+75/100 EPS then you could even do a second membrane to start reinforcing AT, then PIR on top of that is plenty good enough afaic. Diminishing returns are into rows of zeros after the decimal place then in all reality. At some stage you need to just live and get on, vs micromanage every nth degree. Too many people take too long NOT living in their dream home to save £1000 over 10 years and so on….which is 2 days part time work per annum btw.

Yup. I always recommend a sacrificial layer of EPS before membrane, even if you do just a 25mm layer, then DPM, then carry on with the rest of the EPS / PIR. PIR can be thinner for the equivalent value compared to EPS, so 200mm of EPS can be replaced by prob 175mm of PIR in reality, number can be crunched but you’re not going to be far off ‘great’ with 25mm EPS, then 75mm PIR then 100mm PIR, or 2x 100 of EPS over the 25mm layer. Just work out costs and logistics for the extra excavation and muck away, as 25mm saving over a large area soon adds up.

Yup, I agree it seems a bloody good option, even more so for an EnerPHit level refurb. This stuff goes hunting for the gaps you can't see, you fix the ones you can, B I N G O! If you do go that route I'll head up and join in the foam party lol.

I think it was a huge worry with halogen lamps of old as the surface temp of those could get to >200°C!! LEDs run pretty cool by comparison, so when encapsulated in a FR down light I think being against rock wool (naturally fire retardant anyways) I doubt there’s ever going to be an issue in reality. Not having these pushed tight against combustible materials is obvs just good practice / common sense.

Yup. I spoke about your build in particular, and they said pick up the phone, have a chat, send some plans and they’ll quote for your consideration. For the price and the expected excellent result I think (particularly for my favourite ICF……woodcrete) it is a no brainer. They said the latest you can get them in, but defo before boarding out, the better. Makes perfect sense tbh. I asked about the validity of me wanting to do a pos/neg AT test after they’ve left, and they’re pretty damn insistent that you would be better off pledging the money to Christ to put towards a new bike.