Deck repair cost
Repairing a deck costs $500 to $3,000, typically $1,400. The question is not the boards. It is the ledger where the deck meets the house, which is where nearly every deck failure begins.
National average
$1,400
per project
On this page
Repairing a deck costs $500 to $3,000, typically around $1,400. Replacing individual boards is $8 to $30 each. Replacing the whole structure is $30 to $150 a square foot.
The question that decides which you are doing is not the boards. It is the framing underneath, and specifically the ledger board where the deck meets the house, which is where nearly every deck failure begins.
What it costs
| Job | Typical cost |
|---|---|
| Replacing a decking board | $8 to $30 each |
| Replacing several boards, a section | $300 to $1,200 |
| Replacing all decking, keeping the frame | $15 to $45 per sq ft |
| Replacing a joist | $150 to $500 each |
| Replacing the ledger and flashing it properly | $800 to $3,000 |
| Sistering weakened joists | $100 to $300 each |
| Replacing a post | $200 to $700 each |
| New footing under an existing post | $300 to $900 |
| Railing repair | $30 to $100 per linear foot |
| Full railing replacement | $40 to $150 per linear foot |
| Stair tread replacement | $50 to $200 each |
| Full stair rebuild | $500 to $2,500 |
| Re-fastening loose boards, whole deck | $400 to $1,200 |
| Cleaning and resealing | $1.50 to $4 per sq ft |
| Full deck replacement | $30 to $150 per sq ft |
The ledger is the safety issue
Most deck collapses are ledger failures, and they happen with people on the deck.
The ledger is the board bolted to the house that carries one end of the joists. Three things go wrong with it:
Nails instead of bolts. A ledger fastened with nails or deck screws rather than through-bolts or structural screws is not adequately attached. This was common practice decades ago and is not now.
No flashing. Water runs down the house wall, gets behind the ledger, and rots both the ledger and the rim joist of the house it is bolted to. The rot is invisible from above and from below; the deck looks fine until the day it does not.
Rot in the house's rim joist. The worse version of the same problem, where the structure the ledger is bolted to has failed rather than the ledger itself.
Get under the deck with a screwdriver and push hard into the ledger, the rim joist behind it, and the joist ends. Soft wood is the answer. If you can see the ledger and there is no flashing over its top edge, that is the finding.
A properly flashed and bolted ledger replacement is $800 to $3,000 and it is the best money that can be spent on an old deck.
The annual check, which takes twenty minutes
- Push a screwdriver into the ledger, the joist ends, the posts at ground level, and the stair stringers. Soft is rot.
- Look for flashing over the ledger. Its absence is the single most common defect.
- Grab the railing at the top of the stairs and shake it. It should not move.
- Check the posts where they meet concrete or soil. Ground contact is where posts fail.
- Look at the fasteners. Rusted nails backing out, corroded joist hangers, or hangers fastened with roofing nails rather than structural ones.
- Bounce on it. A deck that moves noticeably underfoot has a framing problem, not a decking problem.
Do this every spring. It is the difference between a $1,400 repair and a collapse.
Repair or replace
Repair when the frame is sound and it is the boards, the railing or the stairs that have gone. New decking on a good frame is $15 to $45 a square foot against $30 to $150 for a full rebuild.
Replace when:
- The ledger or the rim joist behind it is rotten
- More than about a quarter of the joists are soft
- The posts have failed at grade
- The deck was built without a permit and does not meet current code for railing height or stair geometry
- It is over about 20 years old in pressure-treated pine and repairs are becoming annual
- You are changing the size or the shape anyway
Frequently asked questions
How long does a deck last?
Pressure-treated pine 15 to 25 years, cedar 15 to 20, composite decking 25 to 30 with a frame that is usually still pine. The frame is what determines the deck's life, and it is the part nobody looks at.
Can I put composite decking on my old frame?
Only if the frame is sound and the joist spacing suits it. Most composite requires joists at 16 inches on centre, and some at 12 for diagonal patterns. An older deck at 24 inch spacing needs joists added, which is $100 to $300 each.
Is a bouncy deck dangerous?
It is a symptom worth diagnosing. It usually means undersized or overspanned joists, missing blocking, or a beam carrying more than it should. None of those improve on their own.
Do I need a permit for a repair?
Usually not for replacing boards or a railing. Usually yes for structural work: the ledger, joists, beams or footings. The inspection on ledger work is worth having.
Why do my deck screws keep backing out?
Nails back out with seasonal movement; screws rarely do unless the wood beneath has softened. If screws are lifting, check the joist under them with a screwdriver.
Read next
How long does a deck last$30 to $100per sq ftA pressure-treated deck lasts 15 to 25 years and composite decking 25 to 30, on a frame that is usually still pine. What ends a deck is almost never the boards you walk on.
Deck railing cost$30 to $150per linear ftDeck railing costs $30 to $150 a linear foot installed. It is frequently a third of the cost of a small deck, because a small deck has almost as much perimeter as a large one.
Deck staining cost$2 to $5per sq ftStaining a deck costs $1.50 to $4.00 a square foot, putting a 300 square foot deck at $450 to $1,200. The cost is not the stain; it is the preparation, and skipping it is why finishes fail in a year.
Composite deck cost$40 to $100per sq ftA composite deck costs $40 to $100 per square foot installed, typically $60. Re-decking a sound existing frame is $20 to $45, less than half the cost of building new.
Deck cost by state$30 to $65per sq ftA pressure-treated deck costs $38 a square foot in Arkansas and $53 in Illinois. On a 300 square foot deck that is $11,400 against $15,900 for identical work.