Cembrit imports Eastern White Cedar Shingles from Canada where the sawmills have for many years treated this natural roofing and cladding material to improve durability. They have continued to improve the treatment process, increasing its effectiveness and removing toxins and solvents.
The latest version of these treatments is Micronised Pressure treatment, which has been used in North America since 2004 and is by far the commonest wood pressure treated in the US. Micronised copper particles are so small that they can be introduced into the timber via water-based solution without the need for solvents. The copper can more effectively be taken into the timber reducing the risk of leaching out into the environment and consequent bio accumulation.
Cembrits shingles are treated with Osmose MicroPro technology, which has been certified under SCS (Scientific Certification Systems) EPP (environmentally preferable product program) based on life cycle assessment. MicroPro also offers GREENGUARD GOLD for low VOC (volatile organic chemical) emissions. These popularly sought accreditations are used by government agencies and other specifiers designing buildings for sensitive applications in North America.
The pigment incorporated in the water solution gives the wood a reddish/brown hue, close to western red cedar. On weathering, MicroPro treated eastern white cedar will fade to the familiar silver grey. It does NOT blacken like western red cedar, which can make an attractive new build look dirty and mould ridden. This is a long term advantage over commonly used western red cedar. Micoronised copper is less corrosive to metals than previous treatments meaning that the longevity of the finished project is enhanced.