Nickfromwales

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.

This is mostly for commissioning the correct flow rates to the spaces served by the unit. Not seen one like that before, so the unit must have (I assume) 3 fans or more. Can you post a link to the actual user / installation manual if possible, please? A bit tricky to pin down the exact instructions for the unit, seems to be a few different offerings. FYI, I would expect (hope) that if doing active heating or cooling, the fan speeds would increase to convey additional volume of air (and heat energy) as at trickle rate the usefulness of those functions would be borderline pathetic. Do you have a pic of the display saying which mode it is in? Does it mention heating and cooling specifically, and can you leave it in max cooling for an hour then go to max heating for an hour, to test these functions at the air inlets?

Ah, yes, my apologies. @Adsibob I thought you meant another Ubiquiti WAP, where it gets power from the source that feeds it, so @MrSniff is correct; you can send the data signal to another mains powered POE switch and gain another x number of powered ports for the POE cameras. I’ll start getting some earlier nights in.

Clients who used Velox had a builder and they ended up rendering with a particular cementitious product before installing cement boards and then brick slips. Took at least 2 coats of that product to get anywhere near good enough to put the boards on, and they’d tried and failed at going straight onto the product with the slips, hence the introduction of a 9mm board. IIRC the boards were dabbed on with that product, which was much like a tile adhesive, and it took a LOT of time and a LOT of money to do. Ironically they chose a very distressed brick and it ended up looking hugely non uniform anyways 🤷‍♂️. If you think you’ll brick slip onto woodcrete think again, so probably a very good idea to fit an insulated tile backer board and slip to that. Just remember it’ll need to have been installed in a way that doesn’t allow airflow behind the boards, or that will cause huge issues with airflow and moisture ingress into that void. It’ll also completely negate the benefit of the insulation effect from the boards; the air gaps would actually make the wall far worse overall. Also, you’ll need to work out the fixing schedule and kg/m2 mechanical load capacity, so the boards don’t just break off the wall with the weight of the slips, adhesive, and pointing mortar. Likely you’ll need to dot n dab these to get flat and plumb, and then when the dabs are dry you drill through and fix at those points. The way I do that is to pre-drill the boards with a 4mm drill bit on the face, then apply the dabs on the reverse to line up with each drill hole (manufacturers will give guidelines for the frequency / distance apart for placement of fixings) and then you know when you screw back through you’re on a dab. Yes, it’s a total PITA. “Enjoy!”. Q: How much of the external facades will be boarded and brick slipped? It may be better to move the airtight layer to the external skin at this point, worth exploring as you could maybe kill a few birds with one stone. Anyone here know of a reason this wouldn’t be possible, assuming the woodcrete was left raw / exposed on the interior and moisture (any) could travel inwards? Would require some quality detailing at the head / foot / openings, but doable perhaps, and could save time and money. Just a lot of work vs EPS……not for me, not after being on these types of builds. Does the manufacturer state a max permissible (dimensional) tolerance for the finished / delivered block?

Waste of time and money. Focus all efforts on the interior surface plz!!

Remember to fill it with concrete first, and let it cure, or you'll just smash straight through the woodcrete. .....*Shiver goes down spine..... Depends on the EPS block type / manufacturer. Nudura for eg have thick plastic / nylon(?) bands running vertically every 405mm (imperial, damn Canadians!) set a few mm into the face of the block for fixings.

Impey stuff is awesome kit, and they do that big FO tanking sheet, the self adhesive one, which also gives 10mm (?) decoupling. Was great the first time I used it and royally fecked it up Man that thing is sticky. Pulled it up, binned it, went and got another one, and then burned through £500 worth of Rubi blades cutting the grade 5 porcelain. Was like cutting titanium. 😵‍💫. Also that 610 liquid rubber adhesive in a mastic tube (Impey supplied it), you used that? I’m sure I still have some stuck to me somewhere, and I did the job a decade ago 🤣. Makes expanding foam seem tame. Had to bin my Stanley knife, and also made the mistakes of a proper rookie, wiped my nose, got it stuck to that, then scratched my head and had to cut it out of my hair. The joys of being on the tools, eh? lol.

Ok, so 550w divided by 230v is = ~2.3amp draw, so seems a bit odd. I’d suggest going through the programmer again to confirm what ‘state’ it is in, eg it is cooling or heating or neither, currently. Maybe perform a factory reset. Also, does it have a display of the 4 ports, with the 4 temps (supply > fresh in / extract > exhaust) etc?

If it cools then it has an inbuilt heat pump. In the last bit of cold weather I suspect this has been sporadically heating, maybe overnight. Is the 550w consumption constant? Fan should be sub 200w.

Hi. Does it have an electrical pre heater in it? This would be to uplift the temp of incoming air, and that would likely be the culprit.

@nod You know what I’m going to say fella Its all about the tanking afaic, and whatever is behind that is doomed, so too is the fabric of the wall or floors, if water gets to them routinely. Tanking strips, corner formers, and tank. Then tank again. Leave to dry, and then tank again where constant flowing water will sit at wall / floor junctions. Water is the enemy not the choice of substrate. I’ve done projects up to the ~£4m price tag, (and everything in between over a 30+ year career ‘on the tools’), and have seen other bathroom fitters / plumbers / tilers on site and my blood has just run cold watching JUST how shit their workmanship was. I’ve been doing or have been around countless high end bathroom / wet-room / kitchen / reno’s projects, and everything right up to full build packages, either on the tools or managing and consulting, and even as far as Q3 of 2024 I still cannot get over the lack of giveafeck that is still out there, even at the absolute top end of the charging / pricing spectrum. Some people think spending huge gets you great, it doesn’t guarantee anything. On a ~£4m 6-bed ‘bungalow’ I watched the plumbing contractors charge >£100k for 1st and 2nd fix plumbing (not inc UFH or heat source) and it was garbage. @nod just give them an email to caveat that they haven’t gone with your professional opinion and recommendations, and cover your arse. If they reply to say they’re happy to take the risk over a grand or so materials uplift then fine, but get it in writing. You’ll probably find that they’ll then change their mind when they realise what cocks they’re being

Parge for airtightness needs to be done internally as the porous blocks will allow airflow (infiltration) in at heads / footer / openings / top course etc, so you’ll need to detail this to the nth degree if you want the results. Just masses of extra hard work, plus your vapour permeability needs managing also so I’d stick to the standard methodology and stay away from creating more work for yourselves. Chasing into woodcrete is something that the prison service should make inmates do. I promise you that crime rates would soon start dropping. You’ll need to surface mount cables, semi-recess deep electrical boxes, and dot n dab onto the blocks. Ive done enough on all types of ICF projects to know what’s a good idea, an “OK” idea, and what’s a “feck that, never again” idea. On one project the annex was done first, as a trial run for the builder, and that ended up with north of 30mm of bonding and plaster over the blocks. They tried to avoid dot n dab in there, I told them not too. Took months and months to dry out, and then hairline cracked EVERYWHERE. I chased that (for my pipes and cables) with a 22mm SDS wood chisel, and that I had to re sharpen with a grinder every 20 mins. After one or two walls you’ll be dragging your metal coffee cup along the bars of the cell.

Depends if you exceed the max w rating of the last powered port. POE to the last switch will be fed from a single port, so there’s the possible bottleneck. Plural (camera's) so how many need to run off the last switch?

Fell out of a Kellog's box over breakfast with the shite he's spouting.... Yup. Most shower traps can have the throat of the trap removed for rodding / clearing with a snake. Most decent BCO's only care about the drainage from DPC and downwards, to the groundworks and sewer etc, and that you have vented or have AAV's (air admittance valves) etc. He needs a holiday, or a beer, or both. Or retire!

Your inspector is a jobsworth muppet. 50mm pipe can easily be rodded with a ‘drain snake’ if necessary, and they really need to take a chill pill. Instal a Y branch at the kitchen sink so you can have a cleaning eye (access cap) there, and then the one most likely to cause issue is covered. Is the stack internal? The general rule is not to have more than 3m of small bore water pipe, assuming 32mm for basins etc and 40mm for everything rise, or upsize if >3m which you have done with the 50mm pipe. Go and push back

Nit picking: I’m a busy man so sometimes spout crap. Check out the small print lol.

You will likely end up in a scenario where the boiler will be routinely producing more heat than the house can dissipate. This results in boiler “short cycling” and also the return temp may be behind the modulation sweet spot.

What is your strategy for meeting part O and getting some active cooling? If you don’t or won’t need the heat then you’ll be well insulated and airtight, yes? <£3k for a good Panasonic monoblock, 5/7kW capacity, and capable of cooling straight out of the box. You’ll need hot water year round, so the perceived savings on heating may be skewed by producing DHW via direct electricity. Solar PV will sort DHW out for a lot of the summer, or batch heating it at night with a bigger cylinder on ultra cheap rate electricity. Summer overheating is the biggest enemy, don’t underestimate this.