CNESST on working at height: the clearance


When working at height with a ladder, the CNESST recommends leaving a clearance zone all around it (at the bottom) and between it and the wall. Whether in the construction industry or for home projects, clearance is an important safety factor when using a ladder. Here are the CNESST safety rules regarding clearance during ladder use. 

Prevention of Falls from Height

Whether it’s for roof repair, shingle installation, adding a ventilation device, installing flashing, gutter maintenance, or even hanging Christmas lights, the CNESST safety rules for work at height should automatically be applied. The same applies for plumbing or electrical work on the roof. Among these rules is the clearance. There are three types of clearance to respect during work at height:

Clearance Around the Ladder

On construction sites, when workers climb onto a roof using a ladder, the base must be surrounded by a safety barrier all around, or another worker must monitor the ladder so that a clearance space is respected around it. This colleague can also hold the base of the ladder and monitor the clearance zone around it.

Clearance Between the Wall and the Ladder

When a ladder is leaned against a wall, there must be a clearance between the wall and the ladder. According to CNESST safety rules for  work at a height of more that 3 meters, the ladder must be held in place by a ladder stabilizer designed for this purpose. The ladder stabilizer is installed on the back of the ladder (at the top) to firmly immobilize it.

Using an aluminum ladder stabilizer (like the PROTECMI ladder stabilizer) allows the ladder to be secured to the wall, while leaving a space of 12 inches [db1] between it and the wall (or roof edge). This protects the gutters and roof edge, while offering freedom of movement during work. Note that the ladder must extend at least 35 inches beyond the roof edge.

Clearance on the Roof

When work is performed on the roof in a workplace (construction sites), the employer must install guardrails to create sufficient clearance space, eliminating any risk of falling from height (safety perimeter). If this is not possible, workers must use a harness that is itself attached to an anchorage point.

In addition to the CNESST rules on work at height regarding clearance around ladders and between the wall and the ladder, you can also refer to the Safety Code for the Construction Industry (RLRQ, chapter S-2.1, r. 4) and the Regulation respecting occupational health and safety (RLRQ, chapter S-2.1, r. 13).

PROTECMI Ladder Stabilizer

Having won the CNESST Grand Innovation Prize in 2020, the PROTECMI aluminum ladder stabilizer allows compliance with CNESST safety rules regarding clearance. It was specifically designed to keep ladders stationary and safe, leaving a clearance of 12 inches between the wall and the ladder.

Additionally, this safety equipment is adjustable depending on the type of roofs or according to the wall on which the ladder is leaned. You will find numbers inscribed on the stabilizer (angle adjuster), for easy installation whether on a sloped roof, a flat roof with parapet, or a flat roof without parapet. 

The angle adjuster lets you place the base of the ladder at an angle of 1/3 or 1/4 relative to the support surface.

Order Your Ladder Stabilizer!

To order your aluminum ladder stabilizer to increase safety on your site or for work at height on your house, visit the Buy section of the PROTECMI Website.

Your residential or professional ladder stabilizer will be delivered within a maximum of 72 hours (to your home or business, throughout Québec).

For delivery elsewhere in Canada, please contact us at 450-753-1010 to proceed with the purchase.