What ho one and all,

Went on my annual pilgrimage to FutureBuild yesterday. Seems to me, when I was called EcoBuild, an company with a product that included the 'eco' exhibited. No longer the case as the buzz words have become, smart, sustainable, environmentally friendly or net zero.

One stand had a shower that is both smart and sustainable. What is a sustainable shower? Could not be bothered to hang around for a free expert to inform me as I come from a cynical position and I doubt that he would have converted me.

Rustins had a stand with G-Therm and G-Insulate paint. Perhaps the G-Therm with graphene is good but the G-Insulate claims of a 21% energy saving from a coat of paint seem like snake oil; but what do I know?

https://www.rustins.ltd/rustins/our-products/speciality-paints/g-therm-thermal-heating-paint

How about wooden nails? Buzzwords are "rethought fastening, sustainable technology." Probably a good idea but in conversation with the guy, he was extolling the virtue of reduced cold bridging and better fire resistance as there is no metal to radiate heat. How much of a problem is cold bridging from nails? www.beck-fastening.com

Some of the PV displays were interesting, particularly one from a Welsh based company, that really does look like a slate tile. Did they have one on display? No, because they are concerned about copying of the product; only photos! https://www.gb-sol.co.uk/products/pvslates/default.htm

GSHP. A number of stands but they all suggest that the cost of a bore hole is so high that it is not practical for an individual build. Since I am not building a block of flats, not a lot of use.

One of my 'soap box' topics was extremely thin on the ground. Why do we use potable water for toilet flushing? There should be compulsory rainwater collection for that purpose installed in every new build, but next to no stands that I could see.

But at the end of the day, guess I had an interesting time.

Toodle pip

Agree about the wooden nails being a good idea but given the surface area of whatever is being nailed down, and in your case the EPS insulation, how much cold bridging do the nails give that it is a problem. I would have thought the heat loss from cold bridging would be virtually insignificant. But what do I know?

What I do know is that my f/f is all 22mm OSB, nailed with a nail gun to the joists. what I cannot see inside, I guess is OK, but there is a section of flat roof over the utility room / garage. The OSB was glued and nailed and covered with a single sheet of EDPM rubber as the waterproof layer. 12 years later, it is quite obvious where the OSB joins are no longer attached to the joists as there is some vertical movement when waling on the roof.

I regret not being more diligent and going around with a box of s/s screws, but at the time, and as a new boy on the block, I assumed the t/f erectors knew what they were doing.

Would wooden 'nails' have been better? Who knows but at the time, they did not exist.

Posted By: RexWhat I do know is that my f/f is all 22mm OSB, nailed with a nail gun to the joists. what I cannot see inside, I guess is OK, but there is a section of flat roof over the utility room / garage. The OSB was glued and nailed and covered with a single sheet of EDPM rubber as the waterproof layer. 12 years later, it is quite obvious where the OSB joins are no longer attached to the joists as there is some vertical movement when waling on the roof.

I would be careful walking on the part over the utility room. If the void is not ventilated and no vapour barrier then it is possible that the boards can rot from condensation. This happened to a relative of mine who had a roof over a garage and it extended over a living area. When hubby walked on the roof to do some maintenance he walked over the garage bit ok but foot went through the boards over the living area. The void was not ventilated and no vapour barrier. The garage bit was open rafters so ventilated. Interestingly it was a new house and had the 10 year warranty but because flat roofs are considered cladding it was not covered.

Posted By: WillInAberdeenM4 mild steel screws on a 600x600 pattern through 100mm EPS, will increase the U value by ~5%.

Which is one reason they use plastic 'nails' on EWI

"I would be careful walking on the part over the utility room. If the void is not ventilated and no vapour barrier then it is possible that the boards can rot from condensation. "

All my insulation is Warmcell but for obvious I did not use it in the flat roof areas. I don't recall if I put installation in the garage roof. However, the BCO checked that I had a ventilation gap from the front to back (garage and utility) and the soffits on all three sides have ventilation strips. Don't go onto the roof very often, usually only to check that everything is OK and clean the algae off the gutter.

As an insulation aside, I don't know what competition Warmcell has in England, but there was a European recycled paper insulation exhibit at FutureBuild - https://www.termex-fibre.com/video/

Posted By: RexSome of the PV displays were interesting, particularly one from a Welsh based company, that really does look like a slate tile. Did they have one on display? No, because they are concerned about copying of the product; only photos!https://www.gb-sol.co.uk/products/pvslates/default.htm" rel="nofollow" >https://www.gb-sol.co.uk/products/pvslates/default.htm

Thanks for the summary Rex. I used to go when I was in London but it seems a long way to go now for sales talk.

We have looked at those PV slates recently. From what I recall the yield is now much better than it used to be, but still at 130 Wp is probably about 60 % of what a typical PV panel can produce over the same area (someone can probably correct my maths). So worth doing in a conservation area but less easy to justify on the average developer new-build estate.

Posted By: jms452Has anyone used/seen these- claimed 95% reduction in embodied carbon over standard bricks - the factory to make them in volume is just opening!

Haven't come across them before, thanks for the pointer. I wonder what the 'secret binder' is? Will it be listed on the BBA Cert or any safety assessment? It still needs some kind of mortar presumably, I wonder if they use normal mortars? And I suppose it still needs wet tradespeople and assembly on-site (barring special facilities) so I probably wouldn't use it myself, but a lot of people might. Purple walls anybody? I wonder how they compare with stabilised-earth bricks or unfired clay bricks?

http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16663

Previous discussion about Kenoteq

Posted By: RexI'm sure it is more expensive than regular DPM material, but looks to be a very good idea.

I think we may have discussed them on here before. Their main purpose is not to act as a DPM but they are used in making a thermal break where walls meet floors etc. (as shown in your link) They're an alternative to the likes of Perinsul blocks.

edit: to correct wording