saveasteading

To give you more assurance. I've worked with so called asbestos roofs a lot. They are actually 98% cement. The fibres are not visible. The only recognised risk is if drilling or grinding and you weren't doing that. We had HSE inspections and never the slightest telling off. I've just looked online. Horsehair or flax look likeliest. Asbestos fibres would have been invisible. The only worrying info is from businesses trying to worry you. Which it seems they have done. So unless you are allergic to horsehair?

A well known business like that will dread any bad publicity. And many / most businesses are perfectly honourable.

But you saw big fibres. If the fibres are there to hold mortar together then they were still doing that, not flying free. The Internet will exaggerate the risk . The number of cases in construction is very low. It's real, and you could better have wetted it and worn masks, but now relax. A professional risk assessment would advise that the risk is small, now totally closed off, and ig wiuld be best not to expose it again unnecessarily. Not to be confused with someone who fancies the opportunity.

Not at all. As @Conorsays your exposure has been very low or zero. And for an example, I was a professional in the industry for 20 years before I found out that most vinyl tiles had asbestos....and we have all walked over them. 1. I've not heard of this use in mortar. 2. It will have come out in lumps, and dust will be sand or cement. As you have seen the fibres you know they are big fibres, not dust. They are lijely yo be hemp or some such. 3. If there was any exposure it was then, and finished. Exposing it again isn't worthwhile. Relax.

Again, for a new post perhaps. I'd love to know more. You appear to have been involved in lots of these experimental processes. I vaguely recall there was such a trend, perhaps 20 years ago.

Low chance of being pursued for it but high risk, and rules are there for a reason. Plus I think it's wrong to expect the neighbours and bco to turn a blind eye. If something was to go wrong, say technically or injury, your insurers would poss jump at the absence of PP to withdraw cover.

I'd never heard of this term, so thanks. Otherwise known as adobe?

Dead right. The contractor must be expert but the SE does the spec. Each should respect the other. How will you know the contractor is expert in reality rather than confidence and chat?

Thanks @Onoff. As you had surmised, I was about to duck out of this. I was wondering if bots were infiltrating BH with click bait. Hence I asked the simple question of why digging was not an option. No answer suggests something untoward. And Out.

I'm being pedantic here. Often there is a difference between "The Requirement" and the multiple explanatories following it, or summaries by other parties. Not all bcos even realise this or appreciate any question of it. Must or should or may? "Must be reasonably airtight" as opposed to ' here are the standards expected. In reality it is usually easier and as cheap to test than to argue the case another way. I haven't done hours of checking this and am not going to... we will get an air test. But if anyone knows I'm wrong, and it is a requirement in the green bit of the regs, I'd be interested.

If i understand. You have been told it dies not qualify as PD. You do not have planning permission. Therefore it is wrong to start. You are hoping to get away with it because you don't think the neighbours would complain. It's wrong to drag them into this. And they or the postman, or anybody might mention it in chat. It would be plain wrong whether you got away with it or not. The bco is not the planner but, if i remember correctly, they would send a notice to the planners. If you explain this all to the bco I doubt it will help; probably the opposite. And what if planning took weeks still because of some random issue? It's generally a bad idea to dig footings too soon. Come January it will all be legitimate and you won't have to worry.

I can see the attraction of icf and I costed out a couple of buildings this way, at design concept/tender stage. It wasn't right for my business and these were both private houses, but I can see the attraction for a self build dwelling. My biggest concern is buukding end of life*. I have a horrible image of the building being scrunched by a concrete crusher and eps being mixed with the rubble or flying off in the wind. Then the crushed concrete being laid as hardcore full of eps. One could redo any "carbon load" with this shown as waste or contamination, to get a different solution. Or perhaps and I hope, this has been thought through and resolved already. * this can be much sooner than the design life due to land use changes.

No please: more distraction. This has got my attention and your experience is wanted. Self evidently, a PV panel will prevent some ( a lot of) solar energy from reaching the roof. Not only is it shade but also the energy is being taken away as electricity. Can you explain why it would be insufficient, in your circumstances of on principle?

I had missed this, now obvious, option! Sedum is very heavy so out of the question. But PV? It's likely this could work. If you were to ask an SE to look into it they might find a bit of spare capacity. Specifying joists is simply choosing the next size up that takes the load, so there is usually some spare. Then they might consider the gantry spanning between structural walls, not all bearing on the roof. OR joists will have little capacity at midspan but more near to the supports... fix there. If the task is to make this specific thing work, then they can look at several options, review other loadings more critically, and even take an overview if it is not quite there. First find a lightweight PV system.

This is top of my head reaction as I dont know your roof product in detail... and given read back. I'm assuming that absorbed heat from direct sunlight is the issue, rather than outside temperatures. A reflective surface would help hugely, but it gets dirty if flattish and looks poor if raked. Might it be more effective to fit an additional roof covering... a sunshade effectively. If this was raised by 50mm or so then it would radiate some heat, have an air gap and also allow air cooling through draughts. The outer material could be metal cladding (uninsulated), board and any waterproofing, or tiles. If the roof was flat then paving slabs on pads. This would reduce the absorbed heat massively.