ROOF TREATMENT GUIDELINES

Shingles and shakes produced from Western Red Cedar (Thuja Plicata) have long been the premier wood roofing material of North America. The majority of cedar roofs remain untreated and are known to provide excellent service.

A surface chemical treatment is desirable, however under conditions which may be conclusive to premature deterioration, such as areas whose climate combines heat and humidity for considerable portions of the year, roofs of low pitch or slope, roofs beneath overhanging trees, etc. There are natural resilient oils present in cedar so it is more advantageous to let the roof weather for approximately one year. Allowing the oils to leach out gives the wood a greater porosity to absorb the preservatives.

Fungicidal chemicals will inhibit moss, fungus and mildew, and will contribute to roof life service. Care should be taken in applying some chemicals because of their toxicity. Follow manufacturer's directions!

In areas of low humidity, where moss, fungus and mildew are not a potential problem, commercial oil based preservatives will prevent excessive dryness and therefore prolong the natural resilience of cedar. In such areas, fungicidal chemicals can be used to good effect, but are not vital.

These surface treatments are temporary and should be applied at approximately five year intervals depending upon the products used. The Shake & Shingle Industry recommends CCA pressure-treated cedar shakes and shingles in the southeastern United States with a climate index of 65 or greater as identified by the USDA Forest Service. The pressure-treatment is permanent and will extend the service life of the roof. Most CCA treated shingles and shakes are available with a 30 year warranty.