Stevensville Bulkhead Leak Sealing

Customer called reporting multiple sinkholes developing behind the bulkhead of a home directly on the Chesapeake Bay. A site investigation determined the customer's bulkhead was suffering damage caused by marine boring worms, leading to erosion as the substrate was pulled out from behind the bulkhead and dispersed into the bay. To address the issue, we first used a process known as curtain wall grouting in which a hydrophobic dual-component polyurethane system is injected using deep injection techniques in a coordinated, predetermined pattern designed to ensure complete coverage of the back wall of the bulkhead. The curtain wall serves several purposes: First and foremost, it seals off any existing leaks in the wall where erosion is actively occurring. Next, the foam deeply penetrates any available gaps and openings along the wall, with high pressure injection and expansion pushing it deep into any available voids, including many of the existing boring sites that are accessible from the back side of the bulkhead. This helps to slow down the active damage being caused by the boring worms in the short term. In addition, as these leaks develop, they begin slowly advancing only with the activity of the worms. As water and sediment begin to move back and forth through the bulkhead wall, this force is heavily destructive and rapidly increases the rate of deterioration. The polyurethane grouting not only helps to seal off any existing sites of deterioration that have not yet had time to fully develop into erosion sites, it also helps to provide an extra layer of support, meaning that as the worm activity continues in the future, the tiny holes opened up by the worms that previously would be exacerbated by the effects of powerful erosion forces are still sealed from behind by the polyurethane thus slowing the rate of deterioration by preventing the abrasive water and sediment slurry from rapidly expanding the newly formed leak. After grouting the bulkhead wall to seal off existing leaks, additional polyurethane material is injected below the surface to fill the voids that had developed as a result of the erosion. This not only helps to fill back in the sinkholes that had formed, it also binds the substrate together in a tightly-bound dense plume. This fortified substrate behind the bulkhead wall is much stronger and more resilient, making it much less capable of easily slipping through any minor points of leaking that may form as a result of additional boring worm damage. Following the polyurethane application and at the customer's request, we also sealed off the front facing wall of the bulkhead with CCA-treated marine lumber to restore the appearance of the bulkhead, covering up the visibly damaged areas. In addition to the aesthetics, this fortification will feasibly provide some additional layer of protective benefit to this section of the bulkhead.