Deck care: inspection, cleaning and when to repair

A deck is exposed to sun, rain, snow and foot traffic, so regular care extends its life and keeps it safe. Structural safety matters most, since a failing deck can cause serious injuries.

The short version: inspect the structure and fasteners every year, clean and seal wood decks as needed, keep drainage clear and repair problems early. If you are unsure about safety, hire a professional.

Annual safety check

• Look at the ledger, the board that attaches the deck to the house, for rot, rust, loose bolts or gaps.
• Check posts, beams and joists for rot, cracks and insects. Probe suspicious wood with a screwdriver.
• Tighten loose bolts and replace corroded hardware.
• Test railings by pushing on them. Wobbly railings are a hazard.
• Check stairs for loose treads and stringers.
• Look underneath for signs of water damage.

Cleaning

Sweep debris out of the gaps between boards, since trapped leaves hold moisture. Wash the surface once or twice a year with a deck cleaner or a mild solution and a soft brush. Use pressure washers carefully, because high pressure can damage wood fibres.

Protecting wood

Wood decks benefit from a stain or sealant that repels water and UV light. Test whether water beads on the surface. If it soaks in, it is time to reseal. Follow the product directions, and apply to a clean, dry surface in suitable weather. Treated lumber still needs care.

Composite and vinyl

These need less upkeep, but they still need cleaning, since mould and mildew can grow. Follow the manufacturer's directions.

Winter care

Use a plastic shovel to remove snow. Avoid metal shovels, which scratch. Be careful with de-icing salts, which can damage some surfaces and hardware. Keep gaps clear so water drains.

Permits and building code

Most decks need a building permit, especially those attached to the house or above a certain height. Repairs may need one too, depending on scope. Check with your municipality, and make sure any new deck meets code for railings, footings and the ledger.

When to replace or rebuild

Widespread rot, a failing ledger or rusted structural connectors are reasons to call a pro. A deck's lifespan depends on the material and care.

Example

A railing that moves when you lean on it is a safety problem. Fix the fasteners or posts before the next gathering.