Nickfromwales

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 👍

I’d say get a quote first, then compare. May just turn out to be quicker, cheaper and better overall.

For a medium sized 3 bed SIPs build they’ve said (ballpark) ~£1500, possibly less, and done in a day! They said they’d deal with sealing up the pre-installed ducts in the slab / foul and waste pipe work etc in that price, but I forgot to ask if they masked up the doors and windows. Worst case there is that you’d have to do that ahead of their attendance, but I’d probably opt to do that myself anyways for peace of mind, say with 4mm hardboard or Antinox (same / other) sheeting, (Link here to random grab) , however, they also said that foam around doors and windows, dressed in properly, would suffice! If so, that would negate all the taping around openings and associated costs, making their price seem unbelievably good value for money. That said, (as I am employed by clients and have to mitigate against failures for 6+ years), I asked if it was better for longevity if the windows and doors etc were AT taped (belt & braces) and the obvs answer was “yes”, but again that’s DIY’able with relative ease. Openable doors and windows are dynamic so there’s going to be movement when slammed shut etc, so my 2 cents is to foam and tape, but the chap says AB is fine to use with just the foam in situ. I think it would be a good day out for me to go see a live install. God I’m boring, I used to be cool. 🥲. AB only do positive pressure testing on the day, not positive > negative x10, but if the air can’t get out then one can only surmise that it cannot get in either? Not sure if that test satisfies BCO, but as you’ll need to do an as-built AT test at the end of the build anyways I guess the matter is moot. I’d wager there are plenty of OCD freaks out there who would do an independent push / pull AT test after AB have left, to check / validate, but I have to admit I’d probably be one of those freaks. I can’t recall if BCOs ask for anything prior to the as-built test as we’ve always done both. Anyone? From what I gathered on the phone to a very helpful chap at AB yesterday, they quote provisionally on a m2 basis, so easy enough for you to get a ballpark number off them for the cost of a phone call / email. @lizzieuk1, the price I had was for SIPs so may be a bit higher for you with woodcrete as I assume it would consume a lot more product? I honestly don’t know, but I will be finding out when I speak to their technical team again for my current and other upcoming build projects. 👌. I had seen the Isotex project get obliterated internally with Passive Purple, and not great results over the woodcrete tbh, not a fault of the product btw just a lot of ‘pores’ to the surface of woodcrete. I also think the installers (marched on by said Neanderthal) could have been more sympathetic, but I think he was limited by IQ. Final result was north of 3ach……😳. I can’t help wondering if the AB system would have been quicker & better there, I very much expect so, but I can tell you hands down it would have been massively, like HUGELY cheaper. The total spend on the woodcrete to get to the point where it was 50% parged (over 100% of the reachable interior surface area) and 100% purple’d was well into 5 figures. They even sprayed the inside of the SIPs roof! For completeness, this was around Covid, and I don’t think there was much noise about AB at that time. It was mentioned here a good while back, but it’s Saturday and I can’t be arsed to look for it. First member to find it wins a prize*. (Please nobody who’s DIY’d respond to those numbers, this was a commercial project where people were charging a premium to operate their companies at the request of the clients who were almost entirely ‘hands off’). Also with noting that Adam White at Intelligent Membranes is a super helpful chap, and he was happy to come to site and meet up with me to discuss the best possible solution (for the Velox project) and between his input, the strategic use of Passive Purple and my OCD / methodology we got that in at 0.88 provisionally and then to 0.66 with some trouble shooting. I think it could (would) have been easy enough to get it much better, sub 0.6, but that’s as close to PH as they needed to be as they didn’t (iirc) go for the arse-ache of full certification. @lizzieuk1 I would recommend you explore this with AB, but either way I would also recommend that you do install other airtight measures at sole plate level > openings > wall plates > roof junctions accordingly, eg the bits / areas people forget about until it’s too late to do anything about it. We can tell you where / how / with what as you progress. You’ll also need to parge the window and door reveals with woodcrete, so the AT tape has something uniform to stick to, also, as AT tape onto a porous / perforated surface will do nothing. On the Velox one where I was instructing the builder on the clients behalf, we put the paint on version of Passive Purple where the tapes landed, which gave excellent adhesion, and that was still getting applied over the parge coat. (The PP can be sprayed or applied by brush / roller, there are 2 different viscosity versions of that product available, to allow either method of application). Maybe the AB route would be quickest and simplest way forward for anyone considering woodcrete, but also (to be fair) this may be better vs tape and membrane regardless. Only place it’s not going to be an option is for cellulose blown frames where the membranes required to hold in the insulation. Last point, I promise, is about timing of when you want to get AB done. I’ve spent a bit of time this week looking into this. It’s less than ideal (but not impossible) to have AB come into an existing residence and make it airtight retrospectively. But just think about the scene from Mr Bean when he masks off everything to paint his house (including each individual grape 🤣 and that’s how far you’d have to go to not have this product nicely layered over everything you own. So get AB in at the point of becoming weathertight, doors and windows in, roof on, no internal finishes on floors or walks etc, and that’s about the sweet spot methinks. * I lied about the prize.

Yes, I do like the logic, it’s just trying to get stubborn architects and designers to lift the needle off their heavily scratched records will be the hard part, as if they don’t agree then you’re back to doing it “the good old way”. I’m currently specifying M&E / renewables / airtightness options etc for a SIPs build client(s) and wish to use the Aero Barrier system for airtightness; the timing is fortuitous to do so right at this moment in the construction phase and would save a lot of labour / membranes / tapes and some possible minimal deconstruction of already installed stud work > external walls & roof if we can. The more I look at the Aero Barrier system, the more I’m liking it tbh. https://www.aerobarrieruk.co.uk For anyone curious. Some good vids on YouTube too. 👍 My difficulty (job for Monday) is to approach the ‘higher powers’ and beg for their almighty permissions, via argumentative logic, for us to do away with the VCL that they’ve specified to be installed on the interior face of the SIPs panels (wall to roof continuous) in light of (near) zero interstitial air or moisture flow in the fabric of the structure; demonstrable by the AT result from Aero Barrier test certification. Anything wrong with that idea folks?

Good to hear yours was that level to just ‘tile’ straight to it with the slips. The Isotex and Velox builds defo didn’t allow for this, nowhere near. I guess this is a warning to remain vigilant at the time it matters most, as some may just steam through the construction and not realise how impactful even a 10mm undulation will be downstream.

Ah……”no”. Those is what the aforementioned builders attempted to do, and they were very good guys; methodical and meticulous in their workmanship but also good at solving issues pragmatically (albeit issues unidentified by the pathetic architect and then left to the builder to resolve, and the client to then have to pay huge amounts to overcome, and repeat) and they gave up and switched to ‘dubbing’ the walls and levelling with 8’ 10 and 12’ straight edges, prior to then installing the backer boards. I’d not seen the slip boards before, but I assume they need a constant and regular structure to fix against do the brick slips don’t all ‘kick’; eg I doubt you can dab / level these “as we go”. The beauty of coming on Buildhub at this stage is to get yourself in check, so happy days. Forewarned is forearmed, and so on

You’d need to extend the entire foundation?! Brick slips attach to the structure. It would be a lot more money to increase the footprint of the foundation for that option and the walls would be enormously thick (380mm block + cavity + bricks)? Your window sills would be resting on next doors dining table.

If these are not wet rooms, and the shower trays are modular (vs wet-room formers under tiles) then just use MR plasterboard and tank the bejesus out of it. Tanking kits are cheap as chips and offer outright resilience to any water ingress beyond the tiles / grout / seals. @BotusBuild Have a scoot through a few of these, saves me getting a sore thumb and there's a load of gold in them there hills for ya :

Ok, then maybe time to ask the collective here if it’s possible to migrate the airtight layer to the exterior and save some time & dosh. ”People, Activate!”. There. I have awoken the gods, now we just sit back and watch the magic happen. Or I get another stupid idea shot to shit.