They may use Exclusive weld pins with integral-cupped head washers. Unfaced boards can then be finished with reinforced insulating cement, canvas, or weatherproof mastic. Confronted boards can be put in in precisely the same way, as well as joints in between boards sealed with stress-sensitive tape or glass cloth and https://freeecogrants.co.uk/how-to-apply-for-loft-insulation-in-the-uk/