Nickfromwales

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.

I spoke to AB as well. In their quote there is no penalty per-se for the woodcrete, and defo no premium / surcharge for using ‘any extra product’. What you get quoted is the price. Also(!) they do all the prep. So masking doors and windows, sealing ducts, looking for obvious leaks / gaps, and then they ‘do their thing’. Price included time & travel, but they ask that if they’re expected to make a good home great, vs them attempting to seal up a complete bag-o-shite (and not meet expectations), then any majorly obvs stuff gets corrected ahead of their arrival. That doesn’t mean parge the woodcrete btw They’ve asked if penetrations and 1st fix can be done if possible, or at least penetrations in abeyance, insulation and screed down, but for no boarding or finishes to be present (ideally). They will AT an existing residence but the prep is then huge and probably then chargeable (?). Defo looking to use them for a current SIPs client, if I can get the architect / PD to agree that if AT is meticulous and the test results officially certified / verified conclude, that we then DO NOT have to install the interval VCL. If there’s no infiltration from atmosphere and the exterior of the SIPs is covered by a breather membrane, then moisture or vapour debate should be moot? Anyone care to tell me if that’s not a robust solution?

Get in line pal.

Then you’ve come to the right place, lol.

Ewwwww. No. Grubby is the word. I would elaborate but it’s too soon after breakfast. For WC height, almost every client I install the Geberit frames for opts to add 25/30mm height, but not go for the huge lift up to ‘comfort’ height.

Relax, I was once as smart as Forrest Gump. We all gotta start with the smallest of steps. You know to ask, which is HUGE Yup, peripheral and intermediate strips, to take loads down to founds where required. They're called constructional slabs iirc. Yes to the PIR skirt aka upstand, as a thermal break. Also, there was a 10mm thick expansion skirting to accept movement from the heated slab (although I think that was just to tick a box afaic). Same size skirt all round as all rising walls from founds will be as cold as Ice Cube when visiting the Nordics in his budgie smugglers.

@lizzieuk1 a blown cellulose roof structure would be very quiet in comparison to a SIPs sandwich, especially if it's a shallow or monopitch with anything other than concrete tiles or slates. Rubber membranes over SIPs is my idea of hell. Easy for me to say that but I have been on both types of clients builds and can say that without hesitation.

I like the sound of that. I wish Nudura would release a UK / European metric version of their block, as an 8' block is great for straight walls and getting some area done PDQ! I'll try and bribe them with some Maple syrup and see if they bite.......

I worked on an ICF foundation that was strip founds and infill slabs, ~120-130mm concrete with UFH and mesh over 100mm of EPS and 100mm of PIR (200mm total insulation thickness). Worked a charm, and would save you the costs and mechanical handling of the B&B. I just don't get the logic of slab (or screed) after slab tbh.

Yup ! @texas can you drain down and check that Y strainer? It's just s a case of unscrewing the big brass hex nut and then the nut and the stainless gauze sleeve will come out with it or you pull it out with your finger. Check for debris, clean, reinstall, try these test again. It seems that the outside tap is teed of the cold mains before the stopcock(s) inside the house which is normal (not unusual). That would account for how it still has pressure on it when everything's off internally and just dribbling.

Belt & braces wins every damn time afaic.... You'll only get one chance to do this properly, and I cannot possibly see why adding glue to the mix would be of any detriment? When installing Egger (P5) floorboards I always use D4 PU glue and 5 screws per joist run, with screws that don't have thread all the way to the head of the screw so there's no risk of 'jacking'. Oh, and don't forget to NOT let that D4 glue get all over your hands, it's a PITA to get off anything, including tools / tape measure etc.

On marketplace here!! If your existing unit is stainless steel it'll outlive us both. Great to see this resolved, and thanks for posting to wrap it up 18 years is pretty good value for money tbh, but quite annoying to see how thin the footprint of the seal at the flange becomes at the bolt holes!

Simple tbh, you just install the roof, add a membrane internally with counter battens for services, parge the top 200mm or so of woodcrete where it meets the membrane, apply some Passive Purple or primer and then tape the membrane to that. Then AB comes in after you 've done all that, and then Bob's your uncle, Fa..................

Ahhh...English....such a beautiful language 🤣

That ICF goon shouldn't make us paint the rest of them with the same shitty brush. Also not the ICF manufacturer at blame there (afaik?), just that goon of a supplier in the UK. Did I mention the word goon?

If defo get the steels in before. Too many variables to do this ‘the other way around’. If you hit the new brickwork with steel you’ll damage it easily too.

The 550w constant is what gets me, as with heating or cooling you’d think it would be on off thermostatically or at least a curve to the consumption?

Elementary my dear Watson. If what I’ve read makes sense, then the airborne atomised product will work its way into the little nooks and crannies, vs try and form a layer on the surface of the block. I think this would consume a bit more product obvs, but looking at previous projects and time / labour / grief, I think this may be the way forward, just to take the plunge and allow the AB system to do its thing. They demonstrate this system closing a hole the size of an A4 sheet down to the size of a postage stamp. I’ll speak to them and see what they have to say, but I doubt the product is that expensive for them to quibble project to project, material to material, perhaps. I’ll let my fingers do the walking 👍