January 9, 2024
If you’ve pondered whether it’s time to check your deck, now’s the moment. A well-constructed deck can endure for decades, but one showing signs of rot, missing fasteners, or instability when walked upon might pose a safety risk. Decks built by inexperienced DIYers, uninspected during construction, or over 15 years old (considering older building codes) are prone to serious issues. Unfortunately, every year, accidents occur — some resulting in severe injuries or worse — when such decks collapse, often during gatherings or parties. The good news is most problems are easily fixable, inexpensive, and swift to address. Your local home centers, lumberyards, or even online sources like strongtie.com offer tools and materials required for the fixes. This article will highlight warning signs of a hazardous deck and provide solutions. If uncertain about your deck’s safety, consider having it inspected by a local building professional.
Issue 1: Inadequate Lag Screws in the Ledger Board
The ledger board, supporting the end of the deck against the house, demands secure fastening to prevent the deck from dislodging. A common issue with DIY decks, as per building inspectors, is insufficiently fastened ledger boards. For a robust connection, a ledger requires 1/2-inch x 3-inch lag screws (or lag bolts if access from inside is available for washers and nuts), ideally spaced every 16 inches. Some ledgers are improperly fastened with nails instead of lag screws and lack washers. To rectify this, start by drilling two 1/4-inch pilot holes at one end of the ledger board, ensuring the holes are offset vertically. Subsequently, drive lag screws (with washers) using a drill and an impact socket, avoiding countersinking as it weakens the ledger board.
Issue 2: Missing or Incorrect Nails in Joist Hangers
Joist hangers, despite having numerous nail holes, require all holes to be filled for stability. Insufficiently nailed hangers risk detachment from the ledger board or rim joist. Sometimes builders initially use a couple of nails to secure the hangers but forget to complete the job later. Correct nails for joist hangers are essential—these are shorter, thicker, galvanized nails designed to withstand heavy loads and treated lumber corrosion. They possess thicker heads and durable galvanized coatings for longevity.
Issue 3: Decay in Deck Support Posts
Deck posts resting directly on footings tend to absorb water and consequently rot, especially if not pressure treated. As they decay, they lose strength, compromising their ability to support the deck’s weight. Modern decks elevate concrete footings above ground level, utilizing special base brackets to keep support posts dry. Ideally, replacing a rotted post is the most effective solution.
Before removing the post, ensure you have all necessary replacement materials, including a wedge anchor. Begin by clearing grass or debris around the base of the post and test its integrity by probing with a screwdriver or awl. If the wood feels soft, spongy, or easily peels away, it’s time for a replacement. To remove the post, brace the deck using nailed-together 2x4s or 2x6s as temporary supports, placing a hydraulic jack underneath. Carefully jack up the brace until snug against the deck without raising it excessively. Add a second brace on the opposite side of the post for stability. Mark the post’s location on the footing, remove the old post, and install a new post base or a wedge anchor if required.
Cut a treated post to fit between the post base and the rim joist. Position the deck support post and secure it to the post base using galvanized nails. Verify the post’s alignment using a level before finalizing its attachment to the rim joist.