What deck stair repair costs
| Job | Typical cost |
|---|---|
| Common stair repairs Per stair | $150–$300 |
| Replace a set of deck stairs Deck frame sound | $500–$1,500 |
| Replacement, per step All-in, professionally installed | $150–$600 |
| Pressure-treated materials Per step | $25–$50 |
| Composite materials Per step | $50–$100 |
| Aluminum or steel materials Per step | $75–$200 |
Where deck stairs fail
- Stringers rotting at the bottom. The cut ends sit on or near the ground and soak up water. This is the most common failure.
- The connection to the deck. Stringers that are only nailed to the rim board pull loose over time. They should hang from metal connectors or a solid ledger.
- Split or cupped treads. Treads take the wear and are the easiest part to replace.
- A loose handrail. Usually the post connection, as with any railing.
- No proper landing. Stairs that end on bare soil sink and rot. They need a concrete pad or footing.
Repair or rebuild?
Treads, risers and handrails can be replaced one at a time. Stringers are different: they are the structure, and a stringer that is soft at the bottom or cracked at a notch cannot be patched reliably. If one stringer has rotted, the others cut from the same lumber at the same time are usually close behind, and a rebuild with new stringers on a proper landing is the lasting fix.
Dimensions that have to be right
- Riser height. No more than 7¾ inches under the model residential code.
- Tread depth. At least 10 inches.
- Consistency. The tallest and shortest riser in a flight may differ by no more than ⅜ inch. An odd step is what trips people.
- Handrail. Required on stairs with four or more risers, set 34 to 38 inches above the tread nosings.
Local codes vary. For railings, see deck railing replacement cost.
How deck stairs are rebuilt
- Measure the total rise from the landing to the deck surface and divide it into equal risers.
- Cut new stringers from pressure-treated lumber rated for ground contact, and seal the cut ends.
- Pour or set a level landing pad so the stringers bear on something solid and dry.
- Hang the stringers from the deck frame with metal connectors, not nails alone.
- Fasten the treads with exterior screws, then fit the posts, handrail and balusters.
If the deck itself needs work, do it together: see deck repair cost.
Common questions
Can I replace just the treads on deck stairs?
Yes, if the stringers are solid. Probe the notches and the bottom ends with a screwdriver first. Soft wood there means the stringers need replacing too.
How many stringers do deck stairs need?
It depends on the tread material and the width of the stairs. Composite treads generally need stringers closer together than wood, so follow the decking manufacturer's span.
Do deck stairs need a handrail?
Under the model residential code, yes, when there are four or more risers. Lower stairs are safer with one too, especially for older family members.
Related guides
Compiled from published 2026 national cost data (HomeGuide, Angi and deck contractor price guides). Dimensions from the International Residential Code; local codes vary. We update these figures as we complete jobs.