Deck collapses are, unfortunately, not an uncommon occurrence in the United States. According to the International Association of Certified Homeowners, only 40 percent of the 45 million existing decks are estimated to be completely safe.
Most deck collapses occur during summer. So, now is the time to check that structures are compliant with today’s building codes.
To encourage compliant deck design, the American Wood Council (AWC) provides a free Design for Code Acceptance 6 – Prescriptive Residential Wood Deck Construction Guide (DCA 6). The guide, available in both English and Spanish, offers guidance on what is required under the International Residential Code for safe deck construction as well as some additional recommendations. Several minimum requirements and limitations for wood deck construction include:
- Minimum post size is 6×6
- All lumber must be preservative treated and identified with a grade mark or certificate of
inspection by an approved bureau or agency
- Nails should be threaded to prevent them from backing out due to moisture cycling
- Appropriate measures must be taken to resist corrosion in all hardware including screws, bolts,
washers, nuts, nails, fasteners and connectors
- Deck ledgers must be adequately attached to the house
- Guard rail posts must not be notched where they attach to the deck
Aside from these minimum requirements, the International Code Council and North American Deck and Railing Association suggest inspecting existing decks for signs that a deck needs to be repaired. These include split or deteriorating wood, loose or missing anchors where the deck is attached to the building, and wobbly handrails or guardrails.
Think Wood and AWC want everyone to enjoy their outdoor spaces and take full advantage of the summer season. Deck safety is a vital place to start.