Symptoms: A deteriorating cap, wavy or sagging panels, cracks / spalling and backfill
settlement.

Cause: This is the result of salt water corrosion and oxidation in the cap reinforcing or
tie-back rods. It could also stem from movement of the structure. The results are upper
rotation, cracking or crumbling of the concrete cap and its ability to keep the slabs
aligned, and/or the slabs moving out of vertical (plumb).

Remedies: If tie-back rods are heavily corroded, excavation may be necessary for their
replacement and integration into a newly poured cap. On many older seawalls, owners
faced with tieback rod failure have installed a new set of tie-back rods and a waler — a
concrete structure that runs the length of the seawall about 2′ below the top on the
water side of the panels. Supplemental helical tiebacks are also a common remedy.