Is Your Exterior Paint Microporous?

Yes, Finngard Opaque, our exterior masonry paint is microporous. The term 'microporous' is often applied to specialist paints and stains and describes a coating that acts as a barrier to liquid water, but allows water vapour to pass through. The special feature about the coating is that it keeps rainwater out of the substrate, but allows moisture that has found its way into the substrate to escape as a vapour. Although almost all coatings will act as a barrier to liquid water, it is not correct to imply that coatings can be made so that moisture vapour can only travel through them in one direction. Moisture vapour will be able to pass through a coating equally well in either direction: from places where there is more moisture, to places where there is less moisture. The rate at which moisture passes through a coating is controlled by the permeability of the coating, the moisture content gradient, the film thickness, and the temperature.

Ultra Primer (for wood) and Finngard Silicone Protect (for masonry) are also considered to be microporous.