FAQ: Seawalls Along the Florida Coastline

How can you tell whether your seawall is eroding?

Most old seawalls were constructed over 50 years ago with heavy concrete slabs supported by rebar and anchors. These walls were designed around a 30-year life expectancy, and most are now in need of repair.

It’s easy to see the tell-tale signs of wall deterioration. Just behind the wall, look for sinkholes that slowly weaken your seawall. Rust-colored cracks in the cap and sheeting below indicate salt water corrosion in the rebar. When rebar corrodes, it expands, causing further cracking in the seawall and allowing backfill to escape through — and sometimes under — the wall. When stressed with a storm event, these cracks can cause the seawall to fail in a catastrophic way.

The wall may kick out at the bottom or lean over at the top, usually caused by a hydrostatic head of water caught behind the wall. The longer you wait, the more catastrophic the failure event.

What Florida Department of Environmental Protection (DEP) regulations in my district should I know about?

Be aware that the State of Florida has regulations specific to each of the districts that control construction near or on the water.

The homeowner is obligated to contact the applicable district office and be aware of the limits and restrictions in her particular county. In most cases, permits are necessary for construction and can be handled by the chosen contractor.

How do modern vinyl and composite materials outperform traditional materials like wood and concrete along the Gulf of Mexico and the Atlantic Ocean?

The thermoplastics of today use new manufacturing technology to create strong, durable materials that will not corrode in a harsh marine environment, one of the biggest factors in seawall failure.

With corrosion no longer a design factor, a lighter material can be used, as it won’t deteriorate and lose structural strength over time. Because thermoplastic materials are lighter than traditional materials like steel and concrete, smaller equipment can be used during construction. This reduces disruption to the property, allowing the seawall to be installed faster, and saves dollars in the process.

Even more importantly, thermoplastics do not leach the harmful toxic chemicals used to kill naturally occurring organisms that consume the cellulose found in timber walls. Our healthy Florida waters are cleaner and safer as a result.

Is the anatomy of a seawall different depending on the part of the Florida coast?

Seawall designs vary greatly in the State of Florida, primarily as a result of site conditions and the direct effect of Mother Nature in that particular location.

These variables must be evaluated by a licensed engineer with knowledge of the factors and the effect they have on the wall. Wall height is a big variable, which is affected by the depth of the water, the soils below, the slope of the land, potential surcharges directly behind or near the wall, and exposure to open or protected waters.

We supply a list of many of these site variables to each client so we may evaluate the site and give correct design suggestions, thus protecting the client. Over the past 40 to 50 years, the State of Florida has built seawalls out of treated timber, concrete, steel, aluminum, coquina rock, concrete bags, and even asbestos sheeting. Vinyl and composite sheet pile is replacing these materials, owing to their low costs and tremendous longevity and safety.

What are the necessary components of a Florida seawall?

A seawall is designed as a component system of materials, each providing advantages and benefits that suit the site conditions.

1. The primary component is the sheeting or wall face. Decisions must be made in choosing the material strength, depth, and thickness based on site conditions. Even a color choice is a big decision when choosing the wall face.
2. Cap designs and materials require consideration. Concrete, vinyl, aluminum, treated timber, composite timber, PVC coated steel and composite cap materials are all considered for structural strength, aesthetics and cost.
3. Deadmen systems must be sized properly for site and soil conditions. The materials used vary from treated timber poles to steel, poured concrete and rebar, screw-in anchors and a driven/locked in place earth anchor. We have even seen old guard rails used as long lasting anchors. These anchors are usually attached to the wall face by a hot dipped galvanized steel or stainless steel rod.
4. Wale systems vary in design and material, usually dictated by strength and cost. This is the support beam along the face of the wall that disperses the pressure along the wall and transfers it to the deadmen via the rods. These wales can be made of treated timber (usually above the water line), steel, concrete, composite tubes, aluminum, and the entire concrete cap. The strength, and especially the stiffness, of these materials may dictate how many anchors are used and how frequently. Multiple wales can be used on taller walls and positioned depending on the earth pressure behind the wall.
5. Drainage systems or weep holes are what we call “cheap insurance.” The biggest threat to the integrity of a seawall is unexpected pressure build-up behind the wall (surcharge), usually caused by sudden water pressure after a storm event. This water needs to escape rapidly through french drains or weep holes installed along the wall face, close to the water line. The engineer will design these into the wall to allow proper drainage.

Is seawall repair an affordable option?

The longevity, relatively low cost of materials, ease of installation, and the small footprint of a vinyl or composite sheet pile allows it to be installed just out front of the old seawall, eliminating an expensive removal of the old wall.

This also shortens the construction phase of the project, reducing costs and most of all, the disruption in your backyard. The light weight of materials allows us to get more on a truck, thus lowering freight costs to your home. And with a 50-year, transferable material warranty, this is a tremendous value for your dollar.

Approximately how many projects have you been involved in in Florida?

We’ve never stopped to count. In the 20+ years we’ve been promoting and selling relatively new composite and vinyl materials, we’ve sold seawalls in the thousands all over the world.

Florida just happens to be the Sunshine State, surrounded by water and loaded with lakes that families want to live on and enjoy. The thought of losing that wonderful property causes a family to choose a long lasting, good looking, easy-to-work-with material to protect that property. That keeps the team at Everlast busy here in Florida.

Which cities and neighborhoods do you serve in Florida?

The mass majority of older, deteriorating seawalls are in the horn of Florida as opposed to the newer Panhandle area.
Our Master Distributor, Decks and Docks, has offices positioned along both coastlines, convenient to the entire state of Florida.

There is not a city in the horn of Florida that our trucks cannot deliver the materials necessary to build your wall, with the exception of a concrete truck.

Who are your on-the-ground partners in Florida?

We partner with engineering service organizations, municipalities, marine contractors, government agencies, golf courses, condominium boards, waterfront communities and individual homeowners to offer our knowledge, experience, engineering support and products.

ESP products are distributed throughout the state by our partner Decks-Docks Lumber Company, which is located in 10 Florida coastal locations.

Do Florida’s long, hot summers affect your materials?

We have always been sensitive to the effect of heat and sunlight on our materials. Our industry spends millions of dollars and years of testing (including long-term, ongoing testing) to eliminate the effects of UV rays on a thermal plastic.

Our profiles are made with a special blend of PVC with UV inhibitors, with a thick layer of virgin resin extruded on the exterior to guarantee the product is not affected by the Florida sun. We also advise engineers and contractors to avoid dark vinyl colors in Florida in order to reduce heat absorption in tropical climates.

Our transferable, 50-year warranty says it all. Our composite profile has far more strength than vinyl, and uses a superior UV-resistant polyurethane blend of resin, as well as an internal vail or “t-shirt” on the outer surface to give the internal architecture superior UV protection. We’ve spent millions of dollars developing these products, designed for the most severe environment on earth.

What is the usual cause of damage to seawalls in Florida?

Older walls, weakened day after day by the elements, can suddenly experience an unusual heavy rain or storm that deposits a load of water (and hydrostatic pressure) behind the wall that causes it to fail, or move, at the least.

This is a slow process that grows progressively worse until failure. A wall failure could be no more than a sink hole in the backyard, however it won’t get any better… only worse. Trying to patch the old wall is only a bandage covering a much larger problem.

Given the heavy hurricanes that can hit Florida, what, if anything, does ESP handle differently in the state? Does this vary by location?

A hurricane can come ashore anywhere — on any coast — and cause widespread damage. It can miss us completely, like recently in South Carolina, yet have devastating effects on seawall structures statewide, including levees, dams, and inland weirs controlling water flow.

Our engineers have developed long lasting, strong weir walls that incorporate computerized flood gates that now regulate water levels remotely by iPad apps in advance of storm events. These walls have replaced steel walls that had a history of failing on a consistent basis before our design. We also use Google Earth maps to analyze site conditions for a client that gives our engineers insight into potential destructive wave action that could impact our walls.

As the threat probability increases, like on the open Atlantic or the open Gulf, we recommend the stronger composite profiles and increase the strength profile based on the potential threat.

We’ll even call for a lean concrete backfill for walls subjected to severe wave action, and this goes for both coasts. If we see a serious threat beyond the capability of our products, we recommend a traditional steel sheet pile and walk away, satisfied that we did the right thing.

What’s the Next Step to Learning About Seawalls?

Interested in learning more about seawall construction on your waterfront property? We’re happy to help!

You can contact us or use the form on this page to share your needs and we’ll be in touch ASAP.

If you’re ready for a free estimate delivered to your inbox, you can also ask our experts using our Free Seawall Estimator Request.

We look forward to hearing from you!