Deck repair and restoration.

Boards, railings and stairs are replaceable all day while the structure underneath is sound, and that is a repair worth doing. Once joists have gone soft, posts have moved, or footings have shifted, the arithmetic turns over — fixing those means dismantling the deck anyway, and new boards on a failing frame is money spent on something with a short future. The other honest signal is how many times it has already been patched. A deck repaired three times is telling you something.

Walk the middle of each span and feel for give. Push hard on the railing — it is a guard, and it should not move. Look at the ledger where the deck meets the house, because that connection is the single most common failure point and the most dangerous one. Push a screwdriver into the base of a few posts; if it goes in easily the post is done. Anything soft, springy or moving is a structural question rather than a cosmetic one, and worth getting looked at before the season it gets used.

Deck collapses are almost always a ledger pulling away from the house or a railing giving way, and both tend to happen when the deck is loaded with people. That is worth saying plainly rather than softly. If your deck moves when you lean on the rail, or there is any separation where it meets the house, keep people off it until somebody has looked at it. Nothing about that is alarmist — it is the specific way these structures fail.

A deck that is structurally fine but grey, rough or growing something is usually a cleaning and re-sealing job rather than a rebuild. Doing that on a cycle is far cheaper than replacing boards that were allowed to go too far, and it is the single most effective thing an owner can do to extend a wood deck here. The right time is before it looks like it needs it.