Timber dome structures are usually used to protect and store sand and salt for road maintenance.

Timber dome structures are often used by:

  • transportation and road maintenance teams
  • municipalities
  • snow removal contractors

When timber dome structures collapse, it is usually because of an unbalanced snow load on the structure – usually at the lower panels of the domes.

Ways to prevent injuries

If you are maintaining this structure, we recommend that you:

  • ensure the panel glued joints were constructed correctly
  • regularly remove the snow at the base of the domes
  • put in place a maintenance program
  • conduct regular structural inspections

Employers and owners of timber dome structures should have the structural integrity of the domes they build or acquire inspected by a professional engineer familiar with timber dome construction. Any design flaws or other deficiencies affecting structural integrity found by the professional engineer must be repaired and corrected according to their recommendations.

Legal requirements

The following outlines the legal requirements under the Occupational Health and Safety Act (OHSA) to prevent timber dome structure collapse. Additional requirements may also apply.

An employer shall ensure a building, structure, or any part thereof, or any other part of a workplace, whether temporary or permanent, is capable of supporting any loads applied to it:

  • as determined by the applicable design requirements established under the version of the Building Code that was in force at the time of its construction
  • following such other requirements as may be prescribed
  • following good engineering practice, if subclauses (i) and (ii) do not apply. (OHSA clause 25 (1)(e)(i), (ii), and (iii))

An employer shall acquaint a worker or a person in authority over a worker with any hazard in the work, and in the handling, storage, use, disposal and transport of any article, device, equipment, or a biological, chemical or physical agent (OHSA clause 25(2)(d)). For example, workers should be aware of any hazards involved in operating heavy equipment in or around timber domes.

An employer shall supply information, instruction and supervision to a worker to protect the health or safety of the worker (OHSA clause 25(2)(a)). This information and instruction may include the importance of removing snow around the base of the domes.

An employer shall take every precaution reasonable in the circumstances for the protection of a worker (OHSA clause 25(2)(h)), including those working in or around timber domes.

This resource does not replace the Occupational Health and Safety Act (OHSA) and its regulations and should not be used as or considered legal advice. Health and safety inspectors apply and enforce these laws based on the facts they find in the workplace.