Piotr Bein wrote:
>
> Would someone know how to insulate 4 ft. walls made of stone and brick? The building is 3 storeys high, approx. 35x35 ft. The insulation has to be on the outside face because there are antique frescoes on the inside. The outside will be receiving a stone cladding.
>
> Piotr Bein

Without knowing the design and environment details of the structure and
site, it is nearly impossible to make recommendations.

However, If rigid insulation is possible, consider the use of Borate
impregnated rigid foam insulation. Borates can be added into the foam to
reduce insect nesting and provide some fire retardancy. This typ of
product is available from a couple of manufacturers.

J. Bryan Blundell