Why Use Polyurethane for Seawall Repair?

There is a lot more to learn than meets the eye regarding seawalls. A sea- wall is like a living, breathing thing: especially in how 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 move instead of rebuilding their seawalls. Today, however, signs of seawall distress can be solved before they get too bad by applying polyurethane grouts to seal leaks, fill voids, and stabilize the surrounding soils. 

As tidal flows rise and fall, water pushes through cracks, joints, and defects in seawalls. The water moves in on incoming tides and flows out on outgoing tides. As the water flows out, it carries sand and soil with it, which causes undermining of the structure, causes voids to form, and deteriorates the structural integrity of the seawall. This cycle is exacerbated during periods of heavy rain, which continue the outflow of soil. Polyurethane foams react with moisture in the soil and expand to fill voids while they permeate sandy soil to form a solid, robust, and watertight mass. They have been used extensively in seawall applications to seal cracks, voids, and defects (as well as for filling voids and stabilizing soil).

Why Do Seawalls Deteriorate?

The Elements

Salt corrosion, tidal action, currents, boat wakes, storm surges, and heavy rain events all deliver a constant beating on the seawall. Every time it rains, or the irrigation system runs, all of the groundwater above the waterline has to vent or equalize every time the tide goes out. Tremendous pressures can build up if that water is trapped and cannot get into the sea or the stormwater system.

Structural Aging

Correct construction of a seawall includes a drainage system to handle the bulk of the water from the rain and checking valves, weep holes, or seams to handle the daily influx and outflow from tide and wave action. Over time the materials degrade or can be disturbed by settling. The result is soil loss and the inevitable sinkholes and low spots along the wall. Other times, the weep holes and vents become clogged, and the water has no way to escape except to force its way down and out from underneath the base of the wall. When this occurs, there will again be sinkholes and sometimes wall failure.

Why Use Polyurethane for Seawall Repair?

Non-Intrusive Application

Using small portable equipment, polyurethane can be injected through pipes directly into voids and loose sandy soil.

Proven Solution

Seawall repair resins are used extensively to seal cracks, voids, and defects, fill voids, and stabilize the soil.

Creates an Impermeable Mass

Polyurethane seals leak along the wall, fill the voids, and mix with the soil to form a solid, impenetrable mass.

What Are the Results of Polyurethane Seawall Repair?

Long-Lasting Solution

Carolina Foundation Solutions seawall repair resins cure to a strength greater than crystalline bedrock. Combined with proper drainage, this method can significantly extend the life of your seawall.

Water Tight Seawall

The resin reacts with water or moisture in the soil and expands to fill voids while permeating sandy soil to form a solid, robust, and watertight mass.

For more information on how we can help repair your seawall, call (877) 770-7050 for a free onsite inspection.

This article was initially published on alchemy-spetec.com by Michael Binyaminov on Feb 18, 2020.