They can also use special weld pins with integral-cupped head washers. Unfaced boards can then be finished with strengthened insulating cement, canvas, or weatherproof mastic. Faced boards could be mounted in exactly the same way, and also the joints among boards sealed with strain-delicate tape or glass cloth and mastic. https://freeecogrants.co.uk/what-are-the-benefits-of-applying-for-external-wall-insulation-grants/