The Importance of Wall Ties

Quite possibly one of the most important and easily overlooked by an inexperienced scaffolder is the tie. The tie in scaffolding terms should be viewed as a lifeline that ties the scaffold to a rigid body preventing the scaffold from overturning. Ignoring the guidelines OSHA has set in place for tie spacing and procedures can result in structural damage to both the facade and/or the scaffold, but most importantly can cause serious injury or death to anyone working on or near the scaffold.

What exactly constitutes as a tie? When ties act in a system they are to be capable of resisting both tensile and compressive forces while not being susceptible to any bending moment or shearing. Some common examples of ties are:

• Tube & Clamp - A tube fixed at a node by clamp bracing the scaffold from falling inward while #9 bail wire is attached to counteract the tension



• Eye Bolt & Anchor - An eye bolt is fitted to a wall surface and attached to a node on the scaffold



• Guy Wires - Tension cables that extend to the ground at a set distance from the base in a configuration as to offset each other

A tie is always required when the base of the scaffold exceeds a height to width ratio of 4:1 (California and some local regulations require a 3:1 ratio). The spacing of ties above the 4:1 height, as stated in OSHA 1926.451(c)(1), cannot exceed a horizontal spacing of 30ft and 20ft vertically for widths less than 3ft (26ft for widths greater than 3 ft) unless the manufactures specifies differently. The tie always located at a node in such a manner not to cause a tripping hazard on walking surfaces.

Most importantly when tying into a structure it is crucial for the area of the connection to be analyzed by a competent person in determining whether it is suitable in supporting the loads exerted by the scaffold. All together the ties are literally a part of the scaffold and all of the appropriate measures should be taken in maintaining a safe work environment.