There is no single set of rules for guardrails. The numerical requirements of section 12 of the Regulation respecting occupational health and safety (RSST) apply to temporary guardrails. A guardrail built into a building, such as on a platform, a mezzanine or a fixed walkway, must meet the National Building Code (NBC) as it read at the time of installation. The RSST, on the other hand, says where a guardrail is required. Here is how to find your way.
Key takeaways
- The values in section 12 of the RSST (top rail between 1 m and 1.2 m, loads of 900 N and 450 N, 90 mm toe board) apply to temporary guardrails.
- A guardrail built into a building must meet the NBC as it read at installation: its height and strength depend notably on the type of building and the location.
- The RSST specifies where a guardrail is required: fixed walkways and platforms from a 1.5 m fall, floor openings, service stairs, ramps, fixed ladders.
- If in doubt about which rules apply, have them validated before fabricating or installing.
Temporary or permanent: two sets of rules
The first question is simple: is the guardrail temporary or built into the building? The answer changes the rules that apply.
Temporary guardrails: what section 12 sets
Temporary guardrails must be designed, built and installed to withstand the following minimum loads:
- a horizontal point load of 900 N, applied anywhere on the top rail;
- a vertical load of 450 N, applied to the top rail.
They must also have:
- a top rail between 1 m and 1.2 m above the floor;
- at least one intermediate rail halfway between the top rail and the floor, which may be replaced by balusters or panels;
- a toe board at floor level, at least 90 mm high.
Where workers are concentrated, or where the guardrail may be subjected to unusual pressure, it must be reinforced accordingly.
Permanent guardrails: the National Building Code
Any guardrail built into a building must comply with the NBC as it read at the time of installation. The installation date therefore matters: the version of the code in force at that time is the reference. According to the CNESST, strength, height and opening size are determined notably by the type of building and the location of the guardrail. Construction work of this kind falls to an RBQ-licensed contractor.
That is why this article does not give single figures for a platform, a mezzanine or a fixed walkway. Under the NBC, any floor raised more than 600 mm must have a guardrail, and the cases where the RSST requires one come on top of the NBC's.
Section 12 provides one exception: a guardrail that is part of a piece of equipment. In that case, check with your prevention advisor or the equipment manufacturer.
Where the RSST requires a guardrail
The RSST specifies several situations where a guardrail is required:
| Situation | Requirement | Section |
|---|---|---|
| Fixed walkway or platform | Guardrails on sides exposed to falls of 1.5 m or more. If the floor is open grating and more than 1.8 m high, no opening may let a 30 mm sphere through | 31 |
| Opening in a floor or traffic way | Surrounded by a guardrail or closed with a cover able to support at least 2.4 kN/m² | 14 and 15 |
| Service stairs | Guardrails solidly supported and fastened on open sides, including landings | 22 |
| Ramp | Guardrails on open sides when the fall hazard is 1.5 m or more | 22.1 |
| Fixed ladder | Guardrail around the floor opening, with a removable gate giving access to the ladder | 23 |
| Places where a worker could fall | At the edge of a drop into a liquid or hazardous substance, from 1.5 m into a pit, basin, tub, tank or vat (or when handling a load), and over 3 m in other cases | 33.3 |
Steel, aluminum or stainless?
The choice of material depends on exposure and maintenance, not just appearance.
- Aluminum: light and rust-resistant. Alliance fabricates and installs aluminum guardrails, including floating guardrails: see our aluminum fabrication.
- Stainless: for areas washed often, such as food plants. If the surface is cleaned regularly with chlorinated products, grade 316 is recommended over 304 (see stainless 304 or 316). See also our stainless steel fabrication.
- Painted steel: a common option, but the paint needs upkeep.
Bolted or welded?
Bolted guardrails are easier to dismantle during a repair or a line relocation. Welded sections are generally stiffer.
Either way, the fastening is part of the assembly that must withstand the loads. For a temporary guardrail, section 12 requires it to be designed, built and installed to withstand the minimum loads. For a permanent guardrail, the applicable NBC covers it.
How to validate before fabricating or installing
Ask these six questions, in order:
- Is the guardrail temporary or built into the building?
- If permanent, which version of the NBC applies, given the installation date, the type of building and the location?
- Is it part of a piece of equipment (section 12 exception)?
- What fall height must it cover: 600 mm (NBC), 1.5 m or 3 m (RSST), depending on the case?
- Is the platform open grating? If so, check the 30 mm sphere rule (section 31).
- Who validates and signs: a prevention advisor or an engineer?
FAQ: industrial guardrails in Quebec
How high must an industrial guardrail be?
For a temporary guardrail, the top rail is between 1 m and 1.2 m above the floor (section 12 of the RSST). For a permanent guardrail built into a building, the height depends on the applicable NBC, the type of building and the location.
From what height is a guardrail required?
It depends on the situation. Under the NBC, any floor raised more than 600 mm must have a guardrail. The RSST requires a guardrail on fixed walkways and platforms on sides exposed to falls of 1.5 m or more, and at the edge of a drop in the cases of section 33.3.
Can a cover replace a guardrail around a floor opening?
Yes, in some cases. A floor opening must be surrounded by a guardrail or closed with a cover able to support at least 2.4 kN/m². If a motorized vehicle can drive over it, the cover must withstand at least 3 times the vehicle's maximum load (sections 14 and 15).
Can a guardrail be removed to do a job?
Temporarily, if it prevents a task that could not reasonably be done otherwise. The worker must then wear a harness connected to an anchorage by a fall-arrest connection, and the work area must be marked off to keep out people who are not working there (section 33.3).
Can the intermediate rail be replaced?
For a temporary guardrail, yes: it can be replaced by balusters or panels (section 12).
Does a guardrail around a machine replace a guard?
No, they are two separate means of protection. A guardrail protects against falls. Protection from a machine's hazardous zones falls under the machine safety rules (division XXI of the RSST).
A guardrail project?
Alliance Maintenance Industrielle fabricates and installs aluminum guardrails, including floating guardrails, and fabricates stainless steel handrails, mesh and safety screens. With more than 20 years of experience in the industrial sector, our team can help you clarify your project's requirements. See our projects or call 438-357-8800.
Sources
- Quebec Regulation respecting occupational health and safety (RSST), chapter S-2.1, r. 13
- National Building Code of Canada (NBC), guards
- CNESST — Guardrail requirements (in French)
Photo: Alliance Maintenance Industrielle. This article is for information only: the rules for a specific installation depend on the NBC in force on its installation date, the type of building and the location. Consult a prevention advisor, an engineer or the CNESST.