What's included
- A structural check before any quote: probing joists, beams, posts and the ledger, looking for heave or settlement at footings, and testing every guard and handrail by hand.
- Joist repair by sistering a new treated joist alongside a damaged one, or replacing it outright when rot reaches the hanger or the bearing end.
- Post and footing fixes: re-setting heaved posts, adding standoff bases where posts sit directly on concrete or soil, and new footings below 24 inches where the old ones were shallow.
- Railing and guard repair with posts re-attached using blocking and hardware made for guard loads, not just longer lag screws.
- Stair repair: new stringers, treads and landing support, with uneven risers corrected so every step in the flight matches.
- Ledger leak repair: opening the joint, checking the band joist, installing flashing that sheds water, and adding fasteners or lateral connectors where the original attachment falls short.
- Board replacement with matched or close-match boards, plus an honest note when an older composite color has been discontinued.
Materials we use
| Category | Options |
|---|---|
| Structural repair | Pressure-treated lumber for sister joists and blocking · Galvanized joist hangers, post bases and straps · Structural screws and through-bolts · Metal ledger flashing and self-adhered membrane |
| Footings | New concrete footings below the 24-inch frost line · Standoff post bases that keep end grain off the concrete |
| Surface and guards | Replacement wood boards (pressure-treated or cedar) · Composite boards matched by line and color where still made · Guard-post hardware rated for guard loads · Replacement stair stringers and treads |
| Water management | Sprinkler heads re-aimed or capped near posts, stairs and the ledger · Downspout extensions carried away from deck footings · Rock or gravel under low decks instead of bark mulch against the framing · Joist tape on exposed joist tops whenever boards come up |
How the work goes
Find the cause
Rot has a source: a sprinkler head aimed at a post, a downspout emptying beside a footing, a ledger with no flashing, soil or bark mulch piled against the framing. We trace the water so the repair isn't needed again in two winters.
Check the whole frame
Before pricing a few boards, we look at the structure around them. If rot has spread across several joists, into the ledger or into the beams, we'll say a repair is the wrong place to spend money and show you what we found.
Scope and price in writing
Each repair gets its own line: what failed, what we'll do, and what it fixes. When a repair changes structure — footings, beams, the ledger — we confirm with the building department whether a permit applies before starting.
Make the repair
Damaged members are cut out or sistered, posts are re-set on proper bases, footings are deepened where they heaved, and new connectors go in. Treated cut ends get preservative, and fasteners are rated for the lumber they go into.
Re-check and advise
We push on railings and climb the stairs, re-check the framing around each repair, and list anything worth watching — boards near the end of their life that can wait a season, or a footing to keep an eye on after the next thaw.
Treasure Valley conditions we design for
- Permit needed above
- 12 in
- Frost depth
- 24 in
- Ground snow load
- 20 psf
- Design wind
- 90 mph
- Nights ≤ 32°F / yr
- 108
- Annual precip
- 11.51 in
Sources: City of Boise — Residential Construction brochure; City of Boise — current codes & design criteria; NOAA NCEI U.S. Climate Normals 1991–2020, Boise Air Terminal (USW00024131)
Red flags to watch for in any quote
- New boards screwed over soft joists. If a screwdriver sinks into a joist top, fresh decking only hides the problem until it fails.
- A wobbly railing "fixed" with longer lag screws into a single rim board. Guard posts need blocking or hardware that resists outward force.
- Shims under a heaved post with no work on the footing. If frost lifted it once, it will keep lifting it every winter.
- Caulk over a leaking ledger. Caulk cracks through freeze-thaw cycles; flashing that sheds water is the repair.
- No question about where the water comes from — sprinklers, downspouts, or grade sloping toward the house. A repair that ignores the source is a repair you'll pay for twice.
- A rotted post swapped for a new one buried the same way. Posts rot at the bottom because they sit in soil or in a puddle on a flat footing top; the new post needs a standoff base, not a fresh hole.
Frequently asked questions
- Can a deck be repaired, or does it need replacing?
- Most decks can be repaired when the problem is limited to boards, a stair, a railing or one or two framing members. When probing finds rot across several joists, at the ledger or in the beams, replacement usually costs less over time than chasing repairs. The deck repair-or-replace guide walks through the tests we use.
- Why do deck posts and stairs heave in Boise winters?
- Water in soil expands as it freezes. Boise's frost line is 24 inches, and the airport averages 108 nights at or below 32°F, with 16 days that stay below freezing all day. A footing that stops short of the frost line can lift a little each winter, which shows up as a high post, a tilted landing or a stair pulling away from the deck.
- How much does deck repair cost?
- It depends on what failed and how much of the structure around it needs work. A loose railing or a few boards are small jobs; sistering joists, re-setting footings or opening a leaking ledger take longer. We price each repair as its own line after an inspection. When repairs approach replacement cost, the deck replacement cost guide shows the other side of that decision.
- Is a loose deck railing dangerous?
- It can be. A guard on a deck more than 30 inches above grade is there to stop a fall, so movement at a post is a warning, not a cosmetic issue. The usual cause is a post attached to a single rim board with lag screws that have loosened or rotted out. The fix is re-attaching it with blocking and rated hardware. See our railings and stairs service.
- Do deck repairs need a permit?
- It depends on the scope and the city. Swapping boards is a different matter from changing beams, footings or the ledger, and rebuilding a deck more than 12 inches high in Boise is permit work. Boise's building division takes permit questions at 208-608-7070. We check with the building department before starting any repair that changes the structure, and if a permit is needed, the repair waits for it rather than going in uninspected.
- Can you replace just a few composite boards?
- Usually, if the line and color are still made. Composite weathers slightly and some colors are discontinued, so a new board can look different for a season or longer. When a close match isn't possible, we can move original boards from a less visible spot to the repair and put the new ones where they matter least, such as under a grill or planter. We'll also check the joists under the damaged boards, since a soft spot in the surface often starts below it.
- Can deck repairs be done in winter?
- Many can. Board, railing and stair repairs work on dry days year-round. Footing repairs are harder in frozen ground, and fresh concrete needs protection from freezing, so footing work is easier before Boise's median first freeze on October 21 or after the median last freeze on April 24. A loose guard or a broken stair tread shouldn't wait for spring, though: block it off or brace it until the permanent fix is in.
- What are the warning signs that a deck needs repair?
- Boards that feel soft or spongy, fasteners backing out, a railing that moves when you lean on it, stairs that rock or have pulled away from the deck, posts that look higher or lower than their neighbors, and dark staining or soft wood where the deck meets the house. Rust streaks below hangers and green growth on shaded joists are worth a closer look too. Any one of these is a reason for an inspection before the next season.
Sources
- NOAA NCEI U.S. Climate Normals 1991–2020, Boise Air Terminal (USW00024131) — annual/seasonal
- City of Boise — 301 Current Codes and design criteria (2018 IRC; snow, wind, frost depth)
- City of Boise — Residential construction permit guide (deck, patio cover, pergola rules)
- Idaho Residential Code (2020 Edition, 2018 IRC basis) — Chapter 3: guards R312, stairs R311.7 (UpCodes)
- Idaho Residential Code (2020 Edition, 2018 IRC basis) — Chapter 5: decks R507 (UpCodes)
- American Wood Council — DCA 6 Prescriptive Residential Wood Deck Construction Guide
Last reviewed .