Deck & Railing Safety Checks
A deck is a platform lifted above the ground, and when one fails the fall can be several feet with people and furniture on top. Most failures come from a weak connection to the house, rot or rusted fasteners, and loose railings. A yearly inspection finds these problems early.
- Homeowners
- Renters
- Landlords
Why decks fail
- The ledger board is the board that fastens the deck to the house. Many collapses happen when the ledger pulls away, often because it was attached with nails, or without proper flashing, so water rotted the connection.
- Rot and insect damage in joists, posts and stair stringers, especially where wood stays wet or touches the ground.
- Corroded or loose fasteners and hangers, especially in wet or coastal areas or when the wrong fasteners were used with treated lumber.
- Overloading by crowds, hot tubs, heavy planters or furniture the deck wasn’t built to hold.
- Weak railings that give way when someone leans on them.
- Age. Many decks are not built to last more than 10 to 20 years without repairs.
Inspect the structure
- Ledger: look where the deck meets the house. It should be attached with bolts or structural screws (not just nails), with metal flashing above it that keeps water out. Look for gaps, rust stains, rot, cracked siding or water damage. If you see any, keep people off and call a professional.
- Posts and footings: posts should sit on concrete footings, not directly in soil. Check that they are straight, with no rot or cracks. Push on them to see if they move.
- Joists and beams: look underneath for rot, splits, sagging, or fasteners that have pulled loose. Check where joists connect to the beam and ledger.
- Hangers, brackets and fasteners: look for rust, loose or missing nails and screws, and bent metal. Replace corroded hardware with the right type.
- Boards: check for cracks, warping, soft spots and loose or raised nails and screws that can trip people.
- The screwdriver test: press a screwdriver into suspect wood. If it sinks in easily, the wood is rotten.
- Look under the deck for pests and standing water, and keep plants and debris away from the wood.
Check the railings and guards
- Height: most residential codes require a guard at least 36 inches high on decks that are more than 30 inches above the ground. Commercial and multifamily decks often need 42 inches. Check your local code.
- Spacing: openings should be small enough that a 4-inch sphere can’t pass through, so children can’t slip through.
- Strength: a guard must resist a strong push. Shake the railing and posts. They shouldn’t wobble. Posts should be bolted to the deck framing, not just screwed to the decking.
- Ladder effect: avoid horizontal rails that children can climb.
- Make sure gates latch, and that the railing is continuous along open sides.
Stairs
- Treads should be even, solid and not slippery. Risers (step heights) should be equal.
- Handrails are usually required on stairs with several steps. They should be graspable and secure.
- Check stringers for rot, especially where they touch the ground, and make sure the bottom rests on a solid base.
- Light the steps at night. See Fall Prevention at Home.
Load and use
- Don’t overcrowd the deck. Limit the number of guests, especially for parties.
- Don’t put a hot tub, planters or a large grill on a deck that wasn’t built for it. A hot tub may need an engineer’s check. See Hot Tubs & Spas.
- Don’t use a fire pit or grill on or too close to the deck or house. See Grilling.
- Don’t let snow pile up, which adds weight and rots wood.
Maintenance and repairs
- Inspect your deck at least once a year, and after storms, heavy snow or an impact.
- Clean and seal or stain wood as the maker recommends. Keep gaps between boards clear so water can drain.
- Replace rotten boards and hardware before they get worse.
- Hire a qualified contractor for structural repairs, and get a permit where needed. See Hiring Contractors and Building Permits & Inspections.
- If you rent or own a building with a deck, report problems in writing. See Tenant Safety Rights and Landlord Safety Duties.
When to stay off
Don’t use a deck that is visibly sagging, tilting, pulling away from the house, or has rotten posts or a wobbly railing. Cordon it off and call a professional. If you are buying a home, have a qualified inspector look at the deck.
Yearly deck check
- Ledger is bolted, flashed and dry, with no gaps or rot
- Posts are solid on footings; joists and beams are free of rot
- Hangers and fasteners are not rusted or loose
- Boards have no soft spots or raised nails
- Guards are the right height and sturdy, with openings under 4 inches
- Stairs and handrails are solid; steps are lit
- Load is within limits; fire pit and grill are kept clear
Standards & references
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