Patrick

We build everything from I-Beams in situ - not a problem at all - BUT - we had amazing carpenters- beyond what is your average building crew - so that might be the reason - i got photos in the blog

Airgap ! For your own peace of mind , please put an airgap into your build-up. The more the merrier. LABC is keen on that as well and doesn't allow warm roofs unless warranted by the system provider . All USA instructions are only partially useful as this all depends a lot on climate zone as well .

Just chipping in without being asked... But bathrooms and kitchen was a saving of somewhere in the region of 10£k-15£k .... And I gotten lazy by the time we ordered kitchen ...could have saved another 3-4£k if I did my kitchen research earlier and had spend more time on it .

That's exactly the way to do it. Saved me at least 800-900£/sqm

Half and half . Board is cut to a shape that fits but is inserted into the opening by 10-15mm

50mm oak planks . Sanded smooth and oiled. Would do that again over anything else . I love the chunkyness of it.

Aludex it's called

Catnic is really worst of both worlds. It s like buying a Ferrari with a vauxhall engine - but still paying Ferrari price. Vmzinc - no faults to pick there . Can't really say anything good about the French - apart from that they have vmzinc , acelor and jouanel.

Officially : everything that @SimonDa Said. Unofficially: Sarking boards all day every day and if you rather use something else- use another roofing system .

Difference between the 2 apart from everything that you read before: 1. Zinc needs qualified zinc installers. Ideally these are very skilled craftsmen. That comes at a price. It s most of the time a great result and a "care free package" as they take care of everything 2 . Metal standing seam can be in most cases installed by advances DIY or general builders. This is most of the times more hands on (between a little and a lot) which brings down the price but also varies the quality of the finish (I ve see outstanding results and borderline criminal bodged )

As others mentioned... U value has nothing to do with the coverage . Whether you put tiles, slate, zinc or metal will make virtually no difference in the u value. In terms of zinc - most refer to zinc and really mean standing seam. Zinc is the material. Standing seam is the shape of the roof panels. You can have zinc roofs in other shapes (tiles...) And you can have standing seam in other materials Some previous posted a few alternatives. They are mostly coated metal . Other option would me aluminium. Then comes the question about installation method... Traditional standing seam(zinc) is rolled/formed on site from coils. Needs a specialist installer since not everyone owns the forming machine and knows how to work with the material. Most of the coated steel and aluminium comes in form of pre formed panels . Then there is only the seam to be closed on site with a seaming machine . And last not least there are click systems , where you can install without the need of machines/seamers . Panels come preformed . So it's really 1. Which shape you want (standing seam I presume from your text) 2. Which material do you want ( zinc=most expensive ; Alu= mid price; steel =cheapest) 3.which installation method you prefer (fully trained specialist = most expensive, general builder/roofer= mid price , self install DIY =cheapest) in point 3 : makes not that much sense to buy a DIY system and then hire a trained expert to install it. You might as well go with zinc in that Scenario

What's a retro PCC ?

Clenergy is the second option for clamps if needed but I am tending to agree with @nod

Thanks. Always appreciated to hear this.

Insulation is cellulose blown into the ceilings. Filters are original ones from ubbink Fresh air drawn from outside -close to the gutter... Not specifically dusty or dirty there.