sgt_woulds

I think the point is that this was measured over months and with higher sustained internal moiture levels. But it is pointless discussing technical points without the reports to hand. My old grey cells aren't good enough to remember the details! I'll ask one of our technical guys if he has a copy of the report - I haven't found the same one with an interweb search yet. The one I'm looking for is specific to natural (hygroscopic) insulations which work differently to oil and mineral based systems. It will have to wait until after the Easter break. Like you I have directly rendered woodfibre (mine is over a shitty SIPs build), but I live in a very exposed location on top of a hill in one of the windiest parts of the country, so I'm happy to practice what I preach...

Yes, but it was the freeze thaw that was the specific issue and the fact that there was no other route for the moisture to escape - the high internal humidity restricted flow that way too. While we may have high saturation rates along the UK coast, similar sustained freeze thaw cycles at the same are unlikely. Tested systems e.g. Baumit will take these extremes into account. As ever, informed specification is key. Seek the advice of the woodfibre and render manufacturers and build specific to the local microclimate. This is different to saying:

True enough, and I should have made it clear that I was talking UK generally. The Norway / Finland issues a combination of extreme differences between internal/external conditions for prolonged periods which added internal moisture to external external wet conditions with the added fun of sustained periods below freezing. I'll see if I can find the report but I think they also blamed higher average internal moisture due to saunas and gas cooking, but I might be getting it confused with a similar case on some islands off the coast of Germany. Surprisingly, the reports I've read include poor instalation which I had thought was a UK specific issue. In the UK, except on the coast at the far North of Scotland these specific issues are unlikely to occur. It should be noted that, (unless it is open slatted) where an external ventilated rainscreen is used, an external membrane is still not required for hydrophobic coated woodfibre external insulation. Although membranes are normally specified anyway as BCO 'expect' to see membranes...

Do you have the other half of the Moose report?

You Moosen't feel too bad about it... 🤪

Sorry, that is outdated thinking based on old building standards. It is perfectly acceptable to directly render onto a breathable insulation for a vapour open structure both here and in the whole of Europe. Building inspectors may expect to see a ventilated cavity based on previous experience, but point them to the manufacturers of such systems and they will be placated. Without knowing the construction details, your rotting sole plates indicates a host of other issues, (cold bridging, incorrect insulation type, poor internal VCL detailing). STEICO (and other) woodfibre insulations use a hydrophobic coating on external sheathing boards. In addition to the render it is more than adequate to keep external driven rain away from the structure. Unlike unatural insulations, the woodfibre actively wickes moisture away when conditions allow. Most EWI systems use direct render onto the insulation. Why should this be different for timber frame? Any vapour open structure needs to be properly designed. In Europe, TF houses are built inside out compared to UK; the OSB racking board is fitted inside the frame, not externaly. In this location (with taped joints), the OSB acts as a moisture vapour variable control layer. If fitted externaly, OSB acts as a vapour check and requires an additional internal VCL, the correct sealing of which is vital to prevent issues. The European TF vapour open building method removes any requirements for vapour control membranes, speeding the build and making it far less susceptable to issues caused by innatentive builders. No, it needs taping and sealing as stated previously. Untaped and in a poorly designed wall it is the worst option, since moisture can easily get behind it, but not so easily get out again once it has condesed against the cooler structure. Worst example of this is internal insulation using pre-insulated plaster boards where there is no way to properly seal the joints. Control layers of any kind are rarely done well by the Lesser Spotted Great British Builder. I don't think we have had a breeding pair of Great Builders in the UK for a long time.... This is why a fully breathable structure using natural insulations that doesn't require perfectly sealed membranes just makes more sense. I agree, decrement delay is far more important, espescially if it has a flat roof.

If you used PIR, that is already acting as a VCL. If you are careful with taping then an additional internal VCL would not be needed. I have a combination of PIR and Woodfibre in part of my own roof (due to structural loading, woodfbre alone was too heavy) with the PIR Internal and taped as the VCL.

Using woodfibre & I-Joists with a direct rendered external sheathing board will give you a quick build, that will give you more decrement delay (probably more important than ultimate u-vale in our ever heating world. You can also do away with membranes entirely and have no worries about moisture. The example build up uses (taped and sealed), 15mm OSB3 as a combined racking and V-VCL layer internally. External, directly rendered woodfibre sheathing board. I've shown 240mm I-joists as these are more common, but 220mm are available I've also shown a service void behind the plasterboard as this makes wiring easier.

I assume this is a newish house built in the last couple of years. Do you know who the house builders are? Should be available from your local planning office. Find their contact details and tell them that this is a non-compliant installation and demand that they provide electrician details for reporting to NICEIC / NAPIT. Get as many neighbours invoilved as possible so they sit up and they might take notice. See what reaction you get. The only way that we'll stop all this cowboy bulldust is to hold them to account.

The EU is starting make changes to online selling. We can only hope that our leaders can take note: EU to impose fines on online platforms importing unsafe products

The power outage was not caused by renewables. It was caused by a lack of preparedness in the rest of the system that allowed a cascade of isolated failures to multiply. This is it a great advert for more distributed generation and power storage on the system. With battery storage and grid forming inverters, the drop in frequency that caused the Spanish outage simply would not have happened. Batteries can respond far quicker to frequency failures than conventional rotational generators.

For some reason I cannot zoom into the photo. Also, it would be good to have a shot from further back showing the whole installation.

@alwayslearning22 is this the finished install or did you take the photo when the Sparky was till working on it? Has it been left with the cover missing on the box above? If this is the case, then as well as the single insulated tails it has left live terminals exposed and the cables connected to the unit above are dangling from the terminals rather than being mechanically supported by a gland. This is all kind of wrong!

Ha! I had thought of the gun argument, but didn't go there...

The potential harm from someone 'doing something stupid' is not limited to that person. A house fire wcould also involve family members, visitors, neighbours, and members of the emergency services. We already have a way of ameliorating the potential dangers of PV installations. It is by having a dedicated circuit installed by a qualified electrician.