Many States and municipalities have implemented legislation that requires all new commercial and industrial structures that utilize “truss-type construction” to have a sign warning emergency personnel that the building was built with trusses.
The code defines trusses to include all fabricated components (constructed with diagonal members) made of wood and steel, requires the Signs, Placards or Emblems affixed to the building exterior.
The truss graphics are used for quick assessment of the structure for potential Collapse Dangers associated with truss constructed buildings. The Signs, Placards, Emblems or Stickers are placed on the exterior of buildings with Truss construction.
The use of truss-type construction (a very common, affordable and safe structural system) is a reliable means of spanning large distances and creating open floor space. Trusses are pre-engineered wood or steel, fabricated with diagonal members and used to construct roofs and floors.
However, when exposed to fire, truss construction presents a great danger to firefighting personnel when those structures are involved in fire conditions. Under these fire and heat conditions the truss systems can weaken and fail, leading to roof or floor collapse. Truss systems in a building are covered by roof and floor decking and in many cases not in view. Fires can go undiscovered long enough to weaken the diagonal member connections in as little as 10 minutes. Failure of one truss jeopardizes the entire floor and/or roof system.
By design, the truss members in floor and roof assemblies will collapse, without warning, after being exposed to heat or flame contact for a very short period of time. Because of the inherent danger firefighters must face while operating within these buildings, the Truss Identification Sign Compliance has been instituted to alert personnel of the danger prior to beginning fire suppression operations.
Please review the individual State Municipality codes for exact requirement and placement of the Truss Identification Signs.