At heights, much like guardrails, warning lines are mandatory in certain situations to prevent falls and accidents within the context of the execution of a project. In which cases should they be used, though, and for which types of work? Here are the standards to be respected under the Safety Code for the Construction Industry.
Warning lines can be used:
- On surfaces less than or equal to 15°: In case of specific work on a roof or bridging on surfaces with a slope equal to or less than 15°, a warning line can be used instead of a guardrail.
- At the top of a trench, hole, or escarpment with a depth greater than 3 metres and which may therefore be a source of danger for workers on a construction site or for the public.
- At the edge of a steep cliff, if a guardrail would impede the execution of the work: In certain exceptional situations, when a guardrail would strongly impair the execution of the work or when materials are being delivered, it may exceptionally be replaced by a warning line right at the area in question, and only for the duration of this work.
The characteristics to respect when installing a warning line
Since July 17, 2014, and with Decree 606-2014, the Government of Québec has modified the Safety Code for the Construction Industry by adding warning lines as a new means of legal prevention against falls. These are therefore used to delineate a work perimeter that’s located 2 or more metres from the place where the worker is at risk of falling. According to Section 184.108.40.206 of the SCCI, which defines the characteristics of the correct installation of a warning line, this must be:
- continuous and installed on all sides of the work area that it delimits;
- placed at a distance of 2 m or more from any place where a worker may fall from a height;
- made of a rigid strip, a cable or a chain equipped with flags made of high-visibility materials and placed at intervals of not more than 2 m;
- made of a rigid strip, a cable or a chain able to withstand a tractive force of at least 2.22 kN;
- supported by stanchions placed at intervals of not more than 2.5 m;
- attached to each stanchion so that pushing on the line between 2 stanchions does not reduce the height of the line between adjacent stanchions by an equivalent amount;
- located between 0.7 m above the work surface at the line’s lowest point and 1.2 m above that surface at its highest point;
- capable of withstanding a load of 100 N applied horizontally at the line’s highest point or vertically at its midpoint between 2 stanchions;
- completed at each access point, storage area or hoisting area by a path formed by 2 parallel lines. However, when the path to a point of access to a work area is located at a distance of more than 5 m from it, the warning line does not have to be continued beyond that distance. In places where the access path starts at a roof edge, a guardrail must be installed on the side of the roof, in compliance with section 2.9.2 of the SCCI, so as to cover the first 3 metres on either side of the access path’s starting point.
However, it must always be taken into account that, according to the regulations in effect, the guardrail is the collective protection method to be privileged throughout the duration of the work to combat accidental falls as efficiently as possible.