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OBC DIVISION B · PART 3 · SECTION 3.15 — SIGNS

What are the requirements for roof signs on buildings in Ontario?

Roof signs need a building permit, engineered design of the sign and its supporting frame for wind and other loads, verification that the roof structure can carry the added loads, noncombustible or fire-safe construction where required, and detailing that protects the roof membrane and drainage.

Code reference
Signs erected on or above roofs are regulated signs whose supporting structures must be designed under the structural provisions of the Code for wind, snow and other loads, with the loads transferred to building elements verified as adequate to carry them, and with construction and materials appropriate to their exposure and to fire safety on the roof.
OBC Division B, Section 3.15 (Signs)

Paraphrased for clarity — open this provision in the BUILDAiD Library for the exact wording.

What this means in practice

Roof signs are the most structurally demanding sign type: they sit in the highest wind exposure on the building, and their reactions land on a roof structure that was rarely designed for them. Expect the permit to require an engineer's assessment of the existing roof framing, engineered sign framing, and details showing how supports penetrate or ballast on the membrane without wrecking waterproofing or blocking drainage. Access for maintenance, guarding of walkways, and electrical service routing all need coordination. Older billboard-style roof signs often need condition assessments when tenants change.

Plain language

Putting a sign on a roof is a structural project: engineers must confirm the roof can carry it and that wind will not tear it off, and the installation cannot punch leaks in the roof or block drains. A permit is required.

Related questions

When does a sign need a building permit under the Ontario Building Code?What are the structural requirements for signs under the Ontario Building Code?What rules apply to projecting signs over sidewalks in Ontario?

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This page is provided for general information. Building code requirements depend on your specific project, occupancy and municipality, and code editions change. Always verify requirements against the current Ontario Building Code and confirm with your local building department.