Deck maintenance schedule

Every spring

1. Clear the gaps. Run a putty knife or a gap tool along every board joint. Packed debris holds water against the board edges and the joist tops beneath — the exact place rot starts and the exact place nobody looks.
2. Wash. A deck cleaner and a stiff brush, or low-pressure soft washing. If you use a pressure washer, stay under about 1,500 psi on softwood with a wide fan tip kept moving, or you will furr the surface permanently.
3. Brighten, if the wood is grey. An oxalic acid brightener neutralises an alkaline cleaner and restores the pH so stain penetrates evenly. Skipping it is a common reason a fresh finish goes blotchy.
4. Look underneath with a torch. Dark staining along joist tops, rust streaks below hangers, and anything soft at the ledger or post bases.
5. Check the railing. Push hard on the top rail at every post. Any movement means a connection needs attention now rather than at the end of the season.

Refinishing, by product

Pigment is what blocks UV, so the more opaque the product the longer it lasts — but the more opaque it is, the more it behaves like a film that can peel rather than a finish that wears. The sealing cost calculator works out gallons and shows the true cost per year for each option, which is the comparison that matters.

Horizontal surfaces in full sun always fail first. Expect to refinish the deck floor at least one cycle ahead of the railings.

Every two to three years

• Probe the posts at ground level with a screwdriver. Sound wood resists; softness there is the beginning of a structural problem.
• Check the ledger and the siding just above it the same way, and confirm flashing is visible.
• Tighten anything that has loosened — railing post bolts, stair connections, beam-to-post hardware.
• Replace corroded fasteners rather than adding more beside them. Plain zinc-plated screws in treated lumber will keep corroding.
• Reset any board that has cupped badly enough to hold water. Cupped boards shed water into the gap rather than off the deck.

The small habits that matter most

Keep planters on feet rather than flat on the boards. Anything holding moisture against the surface leaves a dark ring and a soft spot within a season or two.

Move the furniture occasionally, so the finish wears and fades evenly rather than leaving outlines when you eventually rearrange.

Sweep leaves out from under the deck as well as off it. A skirted deck with leaves packed underneath dries far more slowly than an open one, and that slow drying is what rots a frame.

Deal with a soft board immediately. One soft board is a repair; a soft board left for two more winters is usually a soft joist as well.

What composite still needs

Composite removes the staining, not the maintenance. It grows the same surface mould and algae as wood in shaded or damp positions, and the gaps still pack with debris that holds water against the frame below.

So the spring routine is the same minus the finish: clear the gaps, wash with a cleaner suited to composite, and inspect underneath. Avoid pressure washing above the manufacturer's stated limit, because forcing water into the board surface can raise the grain of the wood flour in the composite and leave a permanently rough patch that the warranty will not cover.