Long Term Performance Of Metal Plate Connected Wood Trusses
Question:
How do trussed roofs perform in long-term service? Are there any reports of rusting in the nail plates, rot/insect attack, do-it-yourself modifications, or condensation and ventilation problems in the attic?
Answer:
Metal plate connected wood trusses have been available as a building component in the United States since the early 1950s. The long-term performance for properly designed and installed trusses is outstanding. Today, wood trusses are used in the roof systems of over 60% of all buildings built in the U.S.
Metal plate connected wood trusses are susceptible to any in-service or environmental condition that adversely affects the wood or metal connector plates. Elevated moisture, insects, decay, condensation and ventilation issues must be considered when using trusses, just as these issues must be considered when using other building materials made from wood and steel. Fortunately, these issues can be handled easily and cost effectively during the design stage for both the building and trusses. Trusses are a manufactured component product and should not be field modified without prior approval from the truss manufacturer. SBCA’s Metal Plate Connected Wood Truss Handbook is a comprehensive reference manual that contains considerable information about wood trusses and how to properly use them.