Ontario's deck building codes are not the same as British Columbia's deck building codes. The same goes for each province and territory in the Great White North.  

The National Building Code of Canada sets basic parameters on decks, but provinces each have their own modifications based on climate. 

For example, in northern areas that experience harsher winters, frost level matters more in terms of depth. You would also need to make sure the bottom of footings is deeper in soil than frost level because if the moisture from the frost gets on the underside of footings, it will expand and cause too much pressure, and eventually movement.

While codes do vary by province and building type, they are comprehensive in nature and typically cover the following elements: ledger connection; posts and footing; post-to-beam connections; joists and joist connections; stairs; deck boards; and handrails. 

The codes can offer insight into what property managers can look for in determining whether a deck needs to be repaired or replaced. For example, NADRA offers the following deck-evaluation checklist: 

• Evaluate the condition of rails, guards, and stairs.
• Review screws and board connections to ensure they're not rusted or broken.
• Look for water stains, corrosion, rotting, and debris in cracks. 
• Is the flashing — the metal barrier material that prevents moisture from entering the building — keeping water out? 
• Does the deck sway? 
• Is the deck sinking or heaving? 
• Do the stairs feel sound and solid?