Most waterfront owners realize that their seawall is a valuable investment that protects their home and property from the waters eroding effects. The costs of building a new seawall varies, and depends on several factors including the quantity of materials needed, the type and strength of materials required, soil conditions, accessibility, environment, project difficulty, and timeline. Properly designed, well-constructed seawalls have a life expectancy of 30 – 50 years, if properly maintained. For effective, well-built seawalls, in almost cases, it is more cost effective to repair a current seawall, rather than replace it. Periodic inspections of the seawall, especially after a heavy rainstorm, or major storm, can help owners circumvent serious problems with their seawall, or even “sudden failure.”
Related Blog: How to Know if it’s Time to Replace Your Steel Seawall
Seawalls can be constructed of concrete, steel, PVC, or composite panels that are vertically placed to separate water from adjacent land, reducing erosion of waterfront land. The three distinct parts of a seawall include interlocking panels, a seawall cap which ties the panels together, and tie rods that anchor the seawall, ensuring that it remains erect, and does not fall into the water. There are four types of seawall failure:
1. Waterline Failure
Horizontal cracks may develop in the panels along the waterline, due to aging concrete, rod corrosion, or hydrostatic pressure. Eventually, these cracks lead to the panels breaking along the lines created.
2. Toe and Berm Failure
Fast currents, and wave movements may cause a loss of berm at the bottom of the panels in the water. This deficiency results in:
- Cracked or tilted panels
- Rotated or broken caps
- Gaps between seawall and support pilings
3. Joint Separation
Joint separation results in panels moving vertically apart, allowing soil to pass through the openings. The causes of joint separation include structural faults, age, settling, and inadequate anchoring.
4. Cap Breakdown
Cracking or breaking away of the cap can be caused by corrosion, or panel movement. The breakdown impacts the cap’s ability to keep the panels aligned, and generally results in panels that sag, or are crooked.
Many times, seawall failings can be repaired before they become major issues. Waterfront property owners should be vigilant in checking for cracks, and any voids, or sinkholes that should be filled. If seawalls have severe waterline cracks, the panels should be replaced before they completely break. Caps can often be repaired by patching, which is performed during routine seawall maintenance checks.