Concrete retaining-wall cracks and spalling in Seattle

Record the symptom without naming the cause

Photograph the whole wall and each distress area with a scale and repeatable viewpoint. Mark the date, weather, crack location and direction, approximate width, spall dimensions, exposed steel, rust-colored staining, white deposits, wet areas, clogged outlets, bulging, rotation, settlement above or below, and displaced joints. Do not remove loose concrete from an area where falling material or wall movement creates a hazard.

FHWA retaining-wall inspection material treats cracks or spalls, rust evidence, wall deformation, settlement, drainage performance, ponding, vegetation, and added upslope material as separate condition attributes. That is useful discipline for a private wall: inspect the system rather than zooming in on one crack. FHWA’s concrete reference also lists multiple possible crack mechanisms, which is why a photograph cannot provide a reliable diagnosis by itself.

Sources: [5], [6]

Separate surface repair from stabilization and replacement

A surface repair addresses defined unsound concrete and restores a specified section or protection system. Stabilization changes how a wall resists load or movement. Replacement creates a new wall system and requires a demolition, temporary-support, drainage, and restoration sequence. These scopes should not be presented as interchangeable price options unless the evaluation establishes that each meets the same performance objective.

Seattle permit records illustrate that distinction without prescribing a method. Completed permit 7062673-CN describes concrete buttresses supporting an existing wall. Completed permit 6866583-CN describes soil anchors stabilizing an existing concrete wall. Completed permit 6883907-CN describes replacing a portion of a failed concrete-rubble wall. None states that cracking or spalling alone led to the selected work, and none supplies a standard detail for another property.

Sources: [7], [8], [9], [2]

Require a repair specification, not the word ‘patch’

A useful repair document identifies the assessed cause and limits; demolition boundaries; protection and temporary support; treatment or replacement of reinforcement; substrate preparation; repair material and compatibility; anchors or dowels; placement, consolidation, finish, curing, and weather limits; drainage changes; testing and inspection; and acceptance criteria. The responsible designer should state what requires field verification and who can approve expanded repair limits.

Seattle Building Code Chapter 19 governs structural-concrete materials, quality control, design, and construction and requires construction documents to state key material, reinforcement, anchor, and joint information. The exact code path depends on the structure and project. Do not turn a general code chapter into a homeowner mix design or assume a proprietary coating resolves movement, water pressure, inadequate reinforcement, or unstable soil.

If demolition exposes more deterioration than shown, stop and document it before covering the area. A change process should identify who assesses the new condition, revises the design, updates the permit if required, prices the change, and authorizes work. Concealed reinforcement and substrate conditions are difficult to reconstruct later from a paid invoice alone.

Sources: [4], [3], [2]

Resolve drainage and movement before cosmetic finish

Crack filler, mortar, coating, or a new finish can conceal a monitoring point without correcting the condition that produced it. Map wall and ground movement first, inspect drainage and surface grading, and determine whether the evaluation needs survey measurements, subsurface information, reinforcement locating, sounding, material testing, or another method. The qualified professional should select the investigation and interpret its limits.

Drainage work must identify collection, filtration, maintenance access, and an approved outlet. SDCI notes that a side-sewer permit is needed when wall drainage connects to a side sewer. Do not assume that opening a weep hole, discharging onto a slope or neighbor, or connecting to an unknown pipe is an acceptable cure. Use the drainage-outlet guide to define this branch.

Sources: [1], [2], [5]

Compare bids against the same evaluated limits

Give every bidder the same condition map, reports, drawings, permit status, repair boundaries, access plan, drainage scope, finish standard, inspections, testing, alternates, and change protocol. Compare quantities and unit prices for uncertain deterioration separately from fixed work. One lump sum may assume shallow patching while another includes structural anchorage, temporary support, or replacement; those are not competing prices for the same result.

Ask who performs the structural repair, who supplies any engineered product design, who observes exposed conditions, and what records are delivered. Verify the exact Washington contractor registration, bond, and insurance immediately before signing. Permit history is useful evidence of a named scope but does not establish current status, workmanship, or responsibility for every trade.

Sources: [10], [3], [4]