Seawalls Are Everywhere
Wednesday, November 07
Seawalls are everywhere. There are endless miles and miles of them. If you live in a condominium, HOA, townhouse community, or home along the beach, bay, inter-coastal waterway, or lake, you most likely have one. Most condominiums and community associations do not reserve for seawall major repair and/or replacements. Other than the actual building structure, much of what they protect is not a covered loss under your association's insurance policy, including your swimming pool and other ground-floor elements and facilities. So much of what seawalls protect, if damaged or destroyed, will be an out-of-pocket expense to repair or replace. Most seawalls are not inspected annually and have no maintenance performed on them. If you think a roof is out of sight, out of mind, try seawalls. No one wants to think about increasing the monthly maintenance fees to cover those costs. What shape is your seawall in? As federal and state funding for beach re-nourishment dries up, you’d better have a look at your seawall. Seawall contractors know this, and are gearing up for a bull market in seawall repairs coming soon to a shoreline near you.
Most communities are lulled into a false sense of security when it comes to seawalls, especially along the beach. Federal and state tax dollars have paid to rebuild beaches many times over the past 20 years so they are protected from hurricanes. However, as is and will be the case for the foreseeable future, that funding has ended. As of this writing. for example, Florida's Pinellas County beaches are being restored, adding 300 feet of beach sand along 10 miles of beaches. However, all it will take is a couple of no-name storms or one big storm to erode most if not all of that beautiful new beach sand back into the sea. Then, the only thing standing between the destruction of your buildings is your seawall. Have I painted with an accurate brush a picture you have hidden in your management closet for a couple of decades?
Without a beach, the seawall is the only thing keeping the land under the buildings in place. When the seawall fails, the ground is washed out to sea, causing at least the ground and first floor of the structure to collapse. Other candidates for destruction include your swimming pool, railings, fences, light poles, landscaping, driveways, parking lots, security houses, maintenance rooms, irrigation systems, domestic and reclaimed water pipes, utilities, storm water pipes and drains, and many other community-specific surface and ground floor elements. Suffice it to say, seawalls protect way more than you may have considered. Those seawalls have had a great life the past 20 years or so, because the beach has been maintained during that time. But, just because the waves and water have not been crashing against it, doesn't mean they haven't been aging just as quickly.
Let me also paint picture with regard to coastal structures protecting property and life. Hurricane Katrina caused severe damage to property and life, but it wasn't an epic catastrophe until the levees broke. Your seawall very quietly has been protecting your property and life for a long time. What can you do? Let’s have a look at that.
First you have to understand what causes the problems, so you can do something about it. Salt is the nemesis. Salt is the catalyst the steel needs to start corroding, rusting, expanding, and cracking the concrete, resulting in a "spall." As anyone who lives along salt water knows, salt gets into the concrete and causes major repairs to the walkways, balconies, and parking garages. Seawalls are no different than any other form of exposed concrete. In fact, it gets much less attention, cleaning, and protection than a walkway or balcony, and, by design, has relatively more reinforcing steel than most floors, slabs, beams, and walls. In fact, in most cases, they receive no coatings, no maintenance at all.
Seawalls age, just like everything else on or near the beach at a rapid pace, as compared to inland steel-reinforced concrete structures. You should have your seawall inspected annually by a licensed marine structure contractor or an engineer who specializes in marine structures. They will examine the current status and health, and make recommendations for maintenance and repairs. They can also give you the remaining life expectancy and replacement cost, so that you can establish a reserve fund.
In addition to examining the actual structure, they will offer advice on the use of adjacent facilities. For example, if you are on an inter-coastal waterway or bay, they will look to see if there has been any scouring or prop washing. This occurs when a boat backs into a boat slip and runs the propeller, displacing the sand next to the seawall. One of the reasons is so that they can get closer to the seawall, expanding the length of the useful slip area. However, the sand next to the toe or base of the vertical panel of the seawall is there to hold the panel in place. By design, there should be at least one-half of the panel length covered by sand. Panels are typically 10, 12, or 14 feet in length. Without this sand in place, when enough hydraulic pressure builds from behind the wall, this toe can push outward or fail. Every community association with boat slips should have a rule or restriction against prop washing, end of discussion on that.
Don't want to spend the money for an inspection? Need to justify the expense? Even without a contractor or engineer, anyone can walk along the seawall’s "cap" and look for cracks, rust bleeding through to the concrete surface, chips, and spalls. Cracks usually appear running parallel to the cap’s length. You can take a long stick or pole and measure roughly the depth of water, height to the cap, and estimate whether you have adequate sand cover of the toe. You can walk on a dock and examine the panels to look for usually horizontal cracks along the panel's width. You can dig holes where the tie-backs are located, expose the tie back steel bars, and see if much corrosion has occurred. If you look waterside of where the vertical panels join, with clear water you may see small hills of undisturbed sand leaches out between the panel joints. If this is happening, you may also see a related hole land-side of the cap in your turf. Just filling the hole land-side won't cure the problem, but it will temporarily relieve you from a trip-and-fall liability. There is more to detail about the problems and cures, but that is for another article, or information you should obtain from your local professional.
The longer you leave these problems unattended to, the more you have decreased your seawall’s life expectancy, and the more it will cost you when you finally do get around to doing something about it. It is also true that, when it comes to seawall repairs, nothing is cheap and nothing happens quickly. The licenses for marine contractors are heavily regulated, and the permits involved in whatever will be done take more time than land structure permits. There are always environmental concerns. There are only a limited number of environmentally approved products that can be used, and protections must be put in place waterside of the work areas.
Thankfully, there are things you can do to treat your concrete. There are water-based clear penetrants that can be spray-applied to the exposed surfaces of the concrete, are environmentally approved, and do not cost a fortune. There are epoxies available that can be gravity- and force-fed into the cracks to seal and protect the internal steel from additional exposure to the elements. There are maintenance services you can perform to the tie-backs to coat them and protect them from further deterioration. Again, your local professional can advise you on what can be done to help.
The bottom line here is, do yourself and your community a big favor. Grab a cup of coffee, and take a walk along your seawall and really take a close look at how it is doing. If you see any evidence of aging, or obvious problems, at least have your seawall inspected by a marine contractor or structural marine engineer. It is better to know what shape it is in and what can be done than to ignore it, live in denial, and/or stick your head in the beach sand.