Deck repair, and telling small from serious

What is deck repair?

Deck repair covers everything from swapping a split board to rebuilding a rotted stair or refastening a guard that has worked loose. The useful division is not by cost but by consequence: cosmetic faults are ugly, structural faults are dangerous. Two symptoms sit firmly in the second group - any movement where the deck meets the house, and a guard rail that flexes when you lean on it.

Signs you need deck repair

• A guard rail that gives when you push it, at any height, on any section
• A visible gap opening between the deck and the wall of the house, or fasteners at that line showing rust streaks
• Bounce in the middle of a span that was firm when you moved in
• A post that a screwdriver sinks into near ground level, or that has visibly darkened and softened at the base
• Stair treads that flex, stringers that have split at the notches, or a stair that has separated from the deck edge
• Individual boards splitting, cupping or lifting fasteners across the surface
• Standing water sitting on the deck long after rain has stopped, or persistent damp dark patches
• Rusting or missing structural connectors visible from underneath

Seeing something not on this list? Browse decks problems by symptom →

How deck repair actually works

1. 1

   Diagnosis from underneath, not from the surface

   A repair pro should get under the deck and look at the ledger connection, the posts at their bases, the beams, the joist hangers and the stair stringers. Most of what makes a deck unsafe is invisible from the top, and most of what is visible from the top is cosmetic.

   Watch forA quote for board replacement written without anyone going under. Replacing boards over a compromised frame produces a deck that looks new and is not safer.

2. 2

   Sorting the list into safety and appearance

   You should be told plainly which items make the deck unsafe to use now, which will make it unsafe within a season or two, and which are simply cosmetic. Those are three different budgets and they do not have to be spent at once.

   Watch forA single undivided quote. It removes your ability to prioritise, and it is how a $600 safety issue turns into a $6,000 refresh you did not need this year.

3. 3

   The repair itself

   Board replacement, sistering or replacing a damaged joist, rebuilding a stair, refastening or rebuilding a guard, replacing corroded connectors, adding or correcting flashing at the ledger. Repairs that touch structure often mean pulling boards to get access, so the surface rarely comes through untouched.

   Watch forRepairs that stop at the symptom. A rotted joist end usually means water has been arriving there for years - if nobody finds and fixes where it comes from, the new timber follows the old one.

4. 4

   Permit, where the repair becomes structural

   Cosmetic replacement generally does not need a permit. Rebuilding a stair, altering a guard, replacing framing members or reworking the ledger frequently does, and the work is then judged against current requirements rather than what was originally there.

   Watch forStructural work carried out as "maintenance" to avoid an inspection. If somebody is rebuilding your stairs or your guard, that is exactly the work an inspection is for.

5. 5

   Handover and the honest verdict

   A repair pro who has been under your deck knows roughly how much life is left in it. Ask for that assessment in plain terms, and ask whether they would spend money on it again next year.

   Watch forSilence on remaining life. If a builder repairs a deck they privately think is finished and does not say so, you will spend the same money twice.

What does deck repair cost?

Small repairs - a few boards, a loose section of guard, one stair tread - are usually a few hundred dollars. Once framing, posts or the ledger are involved it climbs quickly into the low thousands, because getting to them means lifting the surface first.

See the full deck repair cost guide - by material, size and region →

If the number is the problem, here are the ways people pay for it →