Truss Signs and Fire Safety

Truss and fire safety sign hero image

You may see these signs on buildings when you are out shopping, going to work, or picking up your children from school. In Florida, the signs are in the shape of a Maltese cross, while in other states, they are shaped as a circle or triangle. The question is: What are these signs, and what do they mean?

Truss signs are specific to states (or cities) and serve to identify buildings that have a light-frame, truss-type construction. What that means is repetitive wood or light steel framing comprises the primary elements of the structure.

This article is a reprint from May 8th, 2012 by Catalog Development Manager, Kristen Hogrefe.


Appearances are deceiving

Buildings that use trusses pose a greater hazard for collapse during a fire than traditional roof and floor construction. The Occupational Safety and Health Administration (OSHA) recognizes the potential hazard posed by truss signs, describing it as a “hazard to the fire service” in the publication Fire Service Features of Buildings and Fire Protection Systems. The publication states:

“Trusses are widely used in construction to span wide areas without the need for vertical supports, reducing both material and construction costs. Under ordinary conditions, trusses work well and building codes have permitted this type of construction for many years. However, trusses often fail suddenly and totally during a fire … It is impossible for crews operating at a fire to predict the time or extent of a collapse since they cannot see how many trusses are affected, which components, and to what extent.”

Thus, a building’s exterior offers no indication to firefighters as to whether or not trusses were used in the construction, and that is why truss signs are important. They provide a visual identifier to warn firefighters about the increased potential for collapse and help them determine whether or not they can safely enter the structure.

The National Institute for Occupational Safety and Health (NIOSH) published an alert on Preventing Injuries and Deaths of Fire Fighters Due to Truss System Failures, recommending that building owners “should consider posting building construction information outside a building to advise fire fighters of the conditions they may encounter.”


No national standard

The National Fire Protection Association (NFPA) has developed voluntary standards that address fire fighter safety related to roof and floor trusses, including NFPA 1620, NFPA 1521, NFPA 1001, and NFPA 921. Some states, such as Florida in rule 69A-3.012, have incorporated NFPA standards into their truss sign laws.

However, there is no national standard for truss signs. Some states and cities have adopted truss sign laws, and although the requirements for truss signs often vary in shape and size, the signs generally share some key elements:

• The letters F, R and F/R appear in the center of the truss sign and indicate whether the Floor, Roof, or Floor and Roof use light-frame truss structures.

• The sign is required to be a bright, reflective color and/or made of a reflective material.


AccuformNMC currently offers truss signs for Florida; New Jersey; New York; Vermont; Mississippi; San Francisco, Calif.; and Acushnet, Mass. If your state or city has truss sign regulations and you need a sign made, contact us today to find out how we can help.


The information provided is for general purposes only, and not to be relied upon as legal advice, legal opinion, and absolute and complete for the specific facts or circumstances.