Summer is the season we all love to enjoy outdoor living, which often includes spending time on your deck. Even decks that appear to be professionally constructed can have defects that might cause their collapse. These defects can be challenging for the average homeowner to recognize.

Every year, more than 2 million decks are built and replaced in North America. However, of the 45 million existing decks, only 40% are considered completely safe. Despite their seemingly simple construction, decks are structures that need to be designed to resist various stresses. Like any other building, a deck must be able to support the weight of people, snow loads, and objects. It should also withstand lateral and uplift loads caused by wind or seismic activity. Ensuring safe deck stairs, graspable handrails, and child-friendly deck rails with proper infill spacing are all essential aspects of deck design.

A deck failure refers to any incident that could lead to injury, including rail failure or total deck collapse. Unfortunately, there is no international system to track deck failures, and each incident is treated as an isolated event rather than a systemic problem. Investigations into the causes of deck failures are rare in most municipalities, and media coverage tends to focus on injuries rather than the underlying causes. Rail failures occur more frequently than total collapses, but they often go unreported due to their less dramatic nature and lower fatality rates.

Some interesting facts about deck failure include:

1. More decks collapse during the summer than in all other seasons combined.

2. Almost every deck collapse occurs while the decks are occupied or under a heavy snow load.

3. There is no correlation between deck failure and whether the deck was built with or without a building permit.

4. There is no correlation between deck failure and whether the deck was constructed by a homeowner or a professional contractor.

5. There is a slight correlation between deck failure and the age of the deck.

Approximately 90% of deck collapses result from the separation of the house and the deck ledger board, causing the deck to swing away from the house. Mid-span breakage of deck floor joists is rare. Rail failure is a more common cause of injuries compared to complete deck collapses. Many DIY homeowners and even contractors often overlook rail infill spacing codes when building decks.

Significant safety hazards are caused by both DIY and commercially built decks that:

1. Lack adequate attachment to the house in terms of the deck’s structure and the use of improper fasteners.

2. Are cantilevered without proper support to prevent weakening and collapse.

3. Are built too high off the ground without adequate supporting members.

4. Are not anchored properly at the base with appropriate footings and piers.

5. Lack proper bracing on their underside.

6. Are built on loose or uneven ground.

7. Have deck planks installed without adequate spacing for rainwater drainage.

8. Have deck planks installed without staggering for adequate load support.

9. Lack proper rail height and width.

10. Have baluster infill spacing that is too wide.

11. Lack graspable handrails on stairs.

12. Lack a GFCI-protected and covered electrical receptacle, especially for outdoor use.

13. Lack adequate exterior lighting on the deck and/or stairs.

14. Have supporting members exposed to excessive moisture, such as from a lawn sprinkler system.

15. Have been constructed with reclaimed wood that is too weathered, dried out, splintered, and/or cracked to safely support the weight of people.

16. Are built over an emergency egress window in the home's basement or lower level.

17. Are built over a septic system or underground storage tank.

Note: Please ensure that all building codes and regulations are followed when constructing or maintaining a deck to ensure safety and compliance with city.