Deck Safety, Porch Collapse, Wooden Decks
Highly rated home inspectors tell Angie's List that about one-third of the decks they check are unsafe, and deck building experts attribute at least 30 deaths to deck collapses in the past several years.
Most of those tragedies occurred when upper floor decks were crowded with friends, families or revelers whose collective weight overloaded the support system, or the supports had structural issues. If yours sags or bounces, it needs some attention from a professional.
Deck safety tips:
- Test railings and banisters: Properly secure any that might be loose. Railings should be at least 36 inches high. Rails should be no more than 4 inches apart.
- Stability: Ledger boards are used to attach decks to houses. Support posts and joist hangers anchor supporting beams under the deck. Support posts should have bracing to prevent lateral movement.
- Wood rot: Wood that is soft and spongy is an indication of decay, which could lead to trouble. Small holes in the wood could be a sign that insects, like carpenter bees, are causing structural problems.
- Fasteners: Replace any nails, screws and anchors that are loose, rusty or corroded. Use bolts instead of nails to fasten wood to wood. Ledger boards should be secured with appropriately-sized lag bolts.
- Inspection: Ask your home inspector for a thorough inspection of the deck, if you’re buying a home that already has one. If you have an existing deck, annual inspections are your best bet to ensure it’s structurally sound.
- Permits: If you’re buying a home with an existing deck, ask for proof that a building permit was issued for the construction and that a certificate of occupancy was issued upon completion. Those documents help ensure the deck was built to the applicable municipality codes and regulations.
- Hire a qualified professional: A well-regarded professional is the best route to go in building or inspecting a deck. If you want to build your own deck, do yourself a favor and get it inspected before you host your first deck party.
- Seal it up: If your deck coating has worn away, clean and waterproof it again. That will help prevent decay in the wood.
- Use pressure treated lumber: That is the most durable when it comes to framing. Untreated lumber will decay faster.
- Make it “Joist” so: Special hangers connect the joists, or support beams, to strengthen load-bearing connections. They are essential to proper deck support.
- Dam it: Don’t forget the flashing, a metal or plastic barrier between the house and ledger board, which keeps water from entering the house.
- Avoid overload: Don’t put a 3,000-pound hot tub on a deck built to withstand 1,400 pounds. Check with a local builder or architect to determine how much weight your deck can support. Most residential decks are built to withstand a minimum of 40 pounds per square foot.