subject: Redwood Painting Guidelines [print this page] Properly specified and applied paint systems perform better on redwood than on practically any other wood substrate. The USDA Forest Products Laboratory ranks redwood in the highest category among softwoods with regard to characteristics for painting and finishing.
For a long-term, low-maintenance service life, high quality paint systems should be applied over the correct grades of kiln dried redwood on structures built with proper construction methods. While the initial cost for painting is higher than for application of natural finishes, the rewards are much longer maintenance cycles and higher levels of protection provided to the substrate. Most natural finishes require reapplication in from one to three years. High quality paint systems typically provide seven to ten years of service.
Paint grades of redwood include Clear All Heart, Clear, Heart Clear, B Grade and Heart B. Sidings, trim and fascia can be solid boards or more economical finger-jointed or end- and edge-glued lumber, and should be specified Certified Kiln Dried. Specify vertical grain for maximum performance. If flat grain lumber is used, install boards with the bark side exposed, as the grain of any species tends to separate or "shell" on the pith side, rupturing the paint film. Specify saw-textured surfaces on flat-grain products to reduce grain raising and improve overall paint performance.
Several keys to a high quality, long-lasting paint job are:
proper siding specification and construction practices,
proper surface preparation and priming,
the selection and proper application of high quality paint products
and, maybe most importantly, not taking any shortcuts.
