jack

Have you read @Bitpipe's posts on this topic? Very useful info.

Gawd dad, you're so embarrassing. I'll be in my room.

You're putting words in my mouth now You said In essence, the concrete burns the foil and renders the board much less effective. I read that as you saying that the loss of the aluminium had a significant impact on the insulation effectiveness of the board. I was simply making the point that the foil contributes nothing to the insulation of the board in an application where there is no air gap (as with Durisol). That's a fact, hence me saying To the extent that my answer addressed that statement, I believe it's correct. If you were saying that damaging the aluminium layer allows subsequent meaningful damage to the underlying board rendering it much less effective, then that isn't something I'm qualified to address. I also don't know exactly what the manufacturers say, nor why they say it. My question was about how much hydrogen is generated and how deeply it potentially penetrates the concrete in a Durisol application. The reactions alone don't provide an answer to that. You also need to look into things like foil thickness (ie, how much hydrogen is generated per unit area) and what the dynamics are of hydrogen gas in this structural arrangement. Again, I'm unqualified to comment, although I have a gut feeling that the damage isn't going to be as bad as you're suggesting. I have pieces of treated softwood left over from the start of our build that have been out in the elements for over two and a half years and they're perfectly fine other than some surface bleaching from the sun. I imagine they'd be in even better condition had they been positioned within an envelope that largely protects them from the vagueries of the British weather. I also have a several hundred year old house just around the corner from that that's still on its original wooden frame. Not softwood, admittedly, but it does illustrate that not all organic material is the same. Durisol says they "mineralise" the wood before they encapsulate it. Anyone know what that means?

Taken to its end point I suppose that means you must object to all forms of wooden construction. I'm not sure it's fair to lump all forms of organic material in with untreated and/or poorly encapsulated sheepswool! You said "In essence, the concrete burns the foil and renders the board much less effective"), To the extent that my answer addressed that statement, I believe it's correct. I'd be interested to know how much hydrogen is generated and how deeply it potentially penetrates the concrete in a Durisol application. I suspect the risk is much higher in a flooring application, where the bubbles are formed underneath a layer of concrete, and could rise into it through buoyancy. In the Durisol application, the hydrogen bubbles would need to move horizontally into the concrete to cause trouble, based on their relative positions in a Durisol wall. Seems less likely than the flooring case. Interesting to hear this though - I'd never really thought about the advice not to allow concrete into contact with foil-faced insulation.

What about putting strips of something over the webs (or maybe every third of fourth web) that will be detectable with a stud-finder? Would aluminium tape work?

Indeed, modern smartphones have several (perhaps 3-5) orders of magnitude more processing power than those probes. From a brief search it looks like they used a 2.3 MHz processor with 18k of memory for the Viking lander.

Just had a thought in the car: When i made the comment above I was thinking about the concrete and cement/wood components and neglecting the rigid insulation in each cavity. So yes, there is cold-bridging. The question is whether it's problematic cold-bridging, and to that I don't know the answer.

We did CAT 6 throughout. Wish I'd done more! Remember that for low-rate applications, you can always add a small switch to multiply out the number of connections you have. Also, as mentioned above, go crazy where there's going to be a TV or the like. Pretty-well everything seems to be internet-connected now. You can have a TV, Sky box, set-top box (eg, Now TV and the like), HD recorder, games console or two, music-streaming device, etc. Longer term, HDMI over CAT 5e/6 for 4k requires more than one CAT cable. Realistically, I'd be putting in at least 4 and ideally 6 runs to your main TV-viewing area now and leaving a duct for future-proofing. I ran the 20-odd cables in our house myself. Piece of the proverbial, as long as you have some help. Termination is pretty easy as long as you're methodical with colours and keeping the wires tightly twisted in pairs all the way to the punch-down points. Take care not to bend the cable too much, especially for CAT 6. I believe this can affect the screening.

Interesting stuff, thanks @najem-icf To be fair, I don't think cement-impregnated wood is anywhere near as attractive to vermin as the sheepswool in that article. What's the U-value of the block material itself? It looks like there's quite a bit of air captured in the shredded wood, which I imagine means it has a U-value that's quite a bit lower than concrete. If that's true, then it's less a case of cold-bridging, and more a case of warm-bridging! Not sure whether that makes any difference to the assessment, but it feels like it'd be less likely to cause a problem than true cold bridging. Thoughts? As you referring to the internal PIR/PUR or a separate later added afterwards? If the former, as I understand it, if there's no gap between the foil and the next surface, the foil contributes nothing to the insulation value anyway, since it can no longer reflect radiated heat. Heat will instead move by conduction due to contact. In that case, it's irrelevant whether the foil is intact.

I had a book about space when I was a kid, bought through one of those school book clubs. There was a large section on the Viking and Voyager probes. I can still remember the pictures, although it must be 30+ years since I last saw them!

Yes, those values were achieved, but not with SIPs. @JSHarris was one of the first in the UK to use MBC Timberframe, an Irish company, which a number of us have since used to build our frames. They do a cellulose-filled twin-stud on insulated raft construction, which achieves the U-values above while avoiding thermal bridging. There's a lot (and I mean a LOT!) of detail about Jeremy's build in his blog.

What a load of cack. Welcome them onto your property, explain the situation, and see what they say. If they talk about enforcement, tell them to have at it but they're wasting their time and money given it's on the way out anyway.

Hi Naj Let me second that. Looking forward to your contributions - always good to have people with knowledge and experience aboard!

And there's the problem. The decision should be the result of the objection, not the other way around. It annoys me that people will take on an important role yet happily remain ignorant of their responsibilities. We know this stuff and we're mostly amateurs!

It really annoys me that planning committees think that their subjective idea of what's attractive in a building is important (incidentally, I believe not liking the "appearance" is not a valid basis for rejecting a planning application - I assume they couched in other terms, like "not in keeping"). Our planning committee is a bunch of elderly, deeply conservative men who want all new houses to look exactly like houses built between 1900 and 1935. It's fine if it's an ugly box as long as it has hung tile and a pitched roof!

While "fora" is the latin plural of "forum", "forums" is more usual in ordinary English.

Welcome Jim. How windy is it in Essex? (Sorry, it'll make more sense when you read some of Ian's posts.) Good luck with the appeal - let us know how you get on.

I'm sure I saw a tyre place near me advertising nitrogen fill as part of their fitting deal. According to this at least, the advantages in that situation aren't necessarily all they're sold to be.

Our experience is different to Jeremy's, partly because of the differences in our microclimate and situation. We get relatively little solar gain due to trees, plus we don't have his nestled-into-a-hill microclimate, so our house is nowhere near as naturally warm as his. On the flipside, we don't have the summer overheating issues he's had in the past - the house has been fine in summer even without using cooling mode on the ASHP.

@Ed_MK, PM me your email address and I'll send you ours. Also agree with looking on the planning portal for your council - the D&A statement is published with all the other documents. @Ferdinand is right that they're no longer compulsory, but it usually makes sense to submit one, especially if there's anything at all unusual or challenging in what you're trying to do.

Because (and I speculate): The fabric of house with the WBS is already not far off the target temp (21 degrees, say), so all the heat goes into overheating not heating up from cold. How many people do you know who have a 3 kW WBS? I've heard of a 4 kW model, but that's at the lowest setting, and I suspect (but don't know) that you'd probably have to get it up higher to start with. You also have residual heat from a WBS. You don't burn it for an hour then have it fall immediately to ambient. Even a small WBS will probably put at least two or three times its kW rating (in kWh) into the house on a minimum length run (ie, a 3 kW stove would likely burn for at least a couple of hours, then take a least another hour to dump its stored heat, amounting to more like 8-10 kWh of energy). The fabric can only absorb heat at a certain rate. The WBS puts out more than that, and the radiant heat it emits quickly makes nearby surfaces very warm (albeit not to much depth). The result is an unpleasant warmth near the WBS. The situation you're describing in your own house is more like running an air heater in a cold room. The air feels warm quite quickly, but if you turn the heater off it quickly gets cold again because all the surfaces in the room are cold. Give it time.

Oooh, nice!

We?

It's stuff I've largely already said. Happy to summarise if and when it comes to that. And I'm not a naughty boy, I'm the messiah!

Yep. We run our unit at the absolute minimum setting when it's just the family in the house. That's about 60% of the mandated rate, and it's perfectly fine.