Repair or replace? How to read a failing seawall

How a typical canal seawall works

A seawall is a retaining wall that happens to sit in water. Panels hold back the soil in your yard. Tiebacks run from the wall back into the yard to anchors buried in the ground, so the wall cannot tip toward the canal. A concrete cap ties the top together. Filter fabric behind the joints lets water pass while keeping soil in.

Most failures start when one of those parts stops doing its job.

What the symptoms usually mean

• Hairline cracks in the cap. Often cosmetic. Worth sealing so water and salt do not reach the steel.
• Rust stains or exposed steel. Steel in the cap or tiebacks is corroding. Corroding steel expands and cracks concrete from the inside.
• Holes or sinking behind the wall. Soil is leaving through a joint or under the toe. This is the one not to wait on.
• A panel leaning or a gap opening between panels. The wall is moving. Often a tieback or anchor has failed.
• The whole wall leaning along its length. The structure as a whole is losing the fight with the soil behind it.

Usually a repair

• Cap cracking or spalling without movement
• One or two joints leaking fill
• A localized washout with the wall still plumb
• A small number of failed tiebacks

Usually a replacement

• Rotation along much of the wall
• Several panels cracked through
• Widespread tieback failure
• Repairs that keep coming back

Questions to ask the contractor

1. What exactly failed, and how do you know?
2. If I choose a repair, how long should it last, and what would make it fail again?
3. If I replace it, why is a repair not enough here?
4. What will you need from me for the permit?

A good contractor will answer all four in plain language.