Maurizio’s interesting career experiences have convinced him that a strong commitment to operational efficiency at all levels is the greatest factor in maximizing safety and productivity. He has been an EHS administrator, construction safety consultant, college instructor, ergonomics specialist, project manager at environmental remediation sites involving radioactive materials, and has worked for OSHA. He has served on boards of directorship and committees and speaks frequently at conferences and conventions.Full Bio
Using standard guard rails as the means of fall protection on a scaffold is generally recognized as providing superior protection than cross bracing alone. This is because the probability of somehow falling over the top rail (or under the mid rail) is presumed to be lower than falling over (or under) the intersection of the braces or through the braces where they attach to the vertical members. I say presumed because it would be pretty unethical to test this out with unlucky volunteers on an actual job site! But, it sounds reasonable. And, ergonomics experts put a lot of research into recommending where guard rails should be based on anthropometric data. They’ve done their homework, and we should always strive for maximum safety even when a lesser option is available.
In the U.S., OSHA requires that the top rail of a standard scaffold guardrail system be installed between 38 and 45 inches (from the deck) for construction activity and between 36 and 42 inches for general industry activity. Mid rails must be installed at approximately half the height of the top rails. Please note that OSHA has a proposed rule, that when made final, will apply the scaffold safety requirements for construction to general industry, so the requirements will eventually be the same regardless of activity type.
However, for construction activity only, at this time, OSHA allows a scaffold’s cross brace to take the place of one, but not both, of the guard rails. If the bracing is installed above a mid rail, then the X intersection must be between 38 and 48 inches from the deck to be compliant when taking the place of the top rail. When bracing is used below the top rail, the X must be between 20 to 30 inches from the deck. Again, OSHA has plans to apply the construction scaffold specs to scaffolds used in general industry, so using a cross brace as one of the guard rails in general industry activity will be permitted when the proposed rule becomes final.
So, if you have the opportunity to use a cross brace in the place of either the top or mid rail, should you do so? Generally speaking, I suggest not to, and OSHA itself has opined that standard guard rails are the superior option. But, there are situations when doing so may provide the same level of protection as standard guard rails, and this is why OSHA permits this practice. Consider the following example.
A contractor utilizes a scaffold specialist to come in and put the thing together and take it apart at the end of the project. And, the specific scaffold that was deemed as most appropriate for the project and chosen by the scaffold specialist comes with the cross brace option due to dimensional and usage considerations. Depending on the specific configuration, it may not be any less safe than standard guard rails. When such a configuration presents itself, it wouldn’t be fair to the contractor (or its scaffold subcontractor) to have to figure out how to fabricate standard rails into the frame when doing so doesn’t improve safety.Please note that OSHA requires guard rails on scaffolds when more than 10 feet above the ground or deck for both construction and general industry activity, though using them at lesser heights is advised when the scaffold design allows for it. OSHA’s standard requirements are the minimum necessary to be in compliance, there is no penalty for surpassing them.