By applying Properla superhydrophobic masonry creme to the exterior walls you will increase thermal resistance, reduce frost damage and prevent the growth of microbial spores.
Tests have shown that a damp content of 5% in a plain brick wall, for example, can lower the insulation performance by up to 50%, especially where cavity wall insulation has been installed. Porous building materials, such as natural stone and brick normally have good insulating properties as they have air filled cavities, which offer low thermal conductivity, but only when they are dry.
By having defected cavity wall insulation removed it will prevent thermal bridging to the interior of your property but will also leave your exterior walls with 0% insulation.