They can also use Particular weld pins with integral-cupped head washers. Unfaced boards can then be concluded with strengthened insulating cement, canvas, or weatherproof mastic. Faced boards could be put in in a similar way, plus the joints in between boards sealed with strain-delicate tape or glass fabric and mastic. https://freeecogrants.co.uk/what-are-the-factors-to-check-before-applying-for-the-free-insulation-grant/