As I said previously in my blog post Stop Erosion Through Your Seawall with Polyurethane:
When it comes to seawalls, there is a lot more to learn than meets the eye. Seawalls are like living, breathing things: especially in the way that they are designed to function. But like all living breathing things, they have a finite lifespan. For many of them, it's a mere 20 – 30 years. Depending on where you live, replacing a seawall can cost anywhere from $150 to $500 per foot. That's enough for some homeowners to choose to move instead of rebuilding their seawalls. Today however, signs of seawall distress can be solved before they get too bad through the application of polyurethane grouts to seal leaks, fill voids, and stabilize the surrounding soils.
Here's a glimpse of polyurethane seawall repair in action. Hang 'Em High Charters in Key Colony Beach, Florida discovered massive voids inside their seawall. Watch closely as they are repaired with AP Lift 475 foam...