They may also use Specific weld pins with integral-cupped head washers. Unfaced boards can then be concluded with strengthened insulating cement, canvas, or weatherproof mastic. Confronted boards is often mounted in precisely the same way, along with the joints among boards sealed with tension-sensitive tape or glass cloth and mastic. https://freeecogrants.co.uk/what-you-should-know-about-solar-energy-grants-uk/