Deck Repair in Boise, ID

What actually breaks on Boise decks?

Boise's climate wears decks out from two directions. In winter the problem is cycling, not cold: NOAA's 1991–2020 normals show 108 nights a year at or below freezing at Boise Air Terminal but only 16 days that stay below freezing all day. Most winter days thaw and most nights refreeze, so any water in a footing hole, a joist top or a fastener hole expands and contracts again and again. In summer it is sun and dry air, with about 55 days at 90°F or hotter and only 11.51 inches of precipitation a year, which checks and splits wood boards and cooks old stain off in a season or two.

That table is why repair calls in Boise cluster in spring. December and January bring about 25 freezing nights each, and by March the ground has been heaving shallow footings for four months. The usual list we see: a stair stringer that has pulled away from its landing, a post that rose and left the beam bearing on one corner, guard posts that rock, and boards that have cupped or split around fasteners.

One more Boise pattern is irrigation. With so little rain, the water that rots deck framing here often comes from lawn sprinklers hitting the same posts, stairs and ledger every summer evening. Redirecting a sprinkler head is the cheapest repair on this page.

Why do decks on the Bench and in West Boise heave?

Because many were never built on frost-depth footings. Ranch houses on the Bench, in Collister and in Vista sit close to grade, so their decks were often set on precast pier blocks or short footings that stop well above Boise's 24-inch frost depth. The 2018 IRC only allows pier blocks under freestanding decks of 200 square feet or less that stay within 20 inches of grade. Attached to the house, a deck on pier blocks rises and falls each winter while the ledger end stays put, and the frame racks a little more each year.

The repair is new footings, not shims. We support the beam temporarily, pour footings to 24 inches beside or under the old supports, and reset the posts on proper bases. If several footings are bad and the joists are tired too, the honest call may be deck replacement in Boise instead. Our Bench neighborhood guide covers why decks there sit so close to the 12-inch permit line.

Is the ledger the problem?

It is the first thing we check, because it is the most dangerous failure. Decks built before ledger flashing was routine were often lagged straight through the siding with nothing to keep water out, and Boise's daily freeze-thaw drives that water into the rim joist behind. Signs include dark streaks on the siding below the ledger, soft wood when probed, and a gap opening between the ledger and the house. The IRC does not allow a ledger to hang on masonry veneer, which rules out bolting to the brick face on some older Boise houses. Our ledger board repair guide explains what a proper fix involves.

Which deck repairs need a Boise building permit?

Structural ones on decks more than 12 inches above grade should be treated as permit work. Boise's rule covers building any deck over 12 inches, and replacing posts, beams, joists or the ledger changes the structure. Boards and loose fasteners on a sound frame are maintenance, but the city's published rules do not spell that out, so we describe the scope to the permit counter at 208-608-7070 before starting. If a repair grows into a rebuild once boards come up, the work stops until the permit is issued. Where footings are replaced under a permit, Boise inspects with holes dug and forms set before any concrete, and inspection requests close at 7:30 a.m.

How are repairs handled on North End and East End historic homes?

With the existing parts as the pattern. Boise's Design Guidelines for Residential Historic Districts say deteriorated or missing pieces of repeated features such as balustrades, columns or stairs may be replaced using the remaining parts to set material, color and design, and that maintenance should rely on cleaning, paint removal and fresh protective coatings. When a porch is beyond repair, whatever survives should guide the replacement, in identical materials where possible.

For a deck or porch in the North End, that means matching original rail profiles and spacing rather than swapping in stock balusters. Boise's Certificate of Appropriateness list names constructing a deck; whether a specific in-kind repair needs a certificate is a question for the preservation planner, and we ask before work starts.

Can a loose guard post wait until spring?

Not on a deck more than 30 inches above grade. The IRC requires a guard there, at least 36 inches tall with openings small enough to stop a 4-inch sphere, and the guard is only as strong as its posts. The American Wood Council's DCA 6 guide details guard-post connections with hold-down hardware rated at 1,800 pounds, a far cry from a post held by two lag screws into a rim joist. Re-anchoring posts with blocking and hold-downs is dry-weather work that does not depend on the season.

Footing repairs are different. Concrete prefers warm ground, so jobs that need new footings fit best between the April 24 median last freeze and the October 21 median first freeze. A deck that is unsafe in January gets shored and blocked off until then.

How a Boise repair visit works

1. Probe every post base, joist end and the ledger, and check footings at any post that has moved.
2. Look for the water source: sprinkler overspray, a downspout or a missing flashing.
3. Write the scope component by component, so you can see what is structural and what is surface.
4. Confirm with the city whether the scope needs a permit, and wait for it if it does.
5. Make the repair, then re-check guards and stairs, since a fixed post often exposes a loose neighbor.

Repair pricing varies more than new construction because no two failures are the same; the Boise deck repair cost guide shows the common repair categories. For routine care between repairs, see deck maintenance for Boise's climate.