If GemThane™ Siding is so waterproof, how does it breathe?
The coatings used for GemThane™ siding are classed as semi-permeable membranes. Water cannot readily penetrate but water vapour can pass through the film. Thus, the moisture content of your siding changes slowly with the seasons but it will not become saturated in wet weather nor parched during dry spells. The latex paints used on other sidings are quite porous, so dramatic swings in water content occur; this permits bacterial growth, makes the wood susceptible to freeze/thaw damage and encourages cracking and splintering.
