If you own waterfront property, you are caught up in the unending battle between ocean and coast. A seawall can be a powerful defense against the tidal waves – until it begins to wear down. Seawall erosion can be virtually nonexistent for certain types of seawall, while for others it may rapidly escalate into an event of catastrophic proportions.
Signs of Seawall Erosion
At times, the signs that indicate a failing seawall can be easy to ignore. Minute cracks near the edge of your patio or gaps at the base of the wall are glossed over. If such damage is allowed to accumulate, it can pose long term danger to your beach property. Keeping an eye out for these signs can help you curb this threat to your real estate.
- Horizontal cracks on the seawall cap, or anywhere else on the surface. The prolonged exposure to saltwater and harsh weather causes the seawall to gradually deteriorate and form cracks.
- ‘Bowing’ or leaning of the seawall is evidence of a failed seawall. If this occurs, water has already begun to penetrate beneath the seawall to erode the soil it is supposed to protect.
- Seawall misalignment is the result of an extreme leaning seawall. The construct moves outward as the anchor rods are no longer capable of keeping the seawall properly aligned. This causes obvious vertical cracks to form on the surface of the wall.
- Sunken areas and sinkholes may appear on the yard behind an eroded seawall. Sinkholes are fairly noticeable. One thing to consider is grass obstruction which is why it is important to check often.
- A landscape void near the seawall base may look harmless, but more often than not it is the direct result of outward movement of the seawall when the anchor rods are corroded.
How to prevent Seawall Erosion
Well-constructed seawalls are generally capable of resisting erosion for long periods, but only if maintenance is performed regularly and proactively. Repairs and may need to be performed frequently depending on the choice of material and the type of seawall installed. In addition, the American Society of Civil Engineers recommends inspection of coastal structures once every five years.
However, the most effective method of preventing seawall erosion is to choose the right type of seawall to install. Making the right choice for your needs can save thousands of dollars in premature repair costs.
The 7 Most Effective Types of Seawall
A common method of classifying coastal seawalls is based on structural form; whether vertical, curved or mound-shaped. The most effective types of seawall generally have curved structures due to the extra protection at the base.
Wood is the classic choice for connoisseurs of the countryside. A wooden seawall complements the waterfront, and adds to the rustic quality of coastal living. Besides its aesthetic value, timber can be obtained cheaper than vinyl, concrete or steel. It is the most economical material for building a seawall.
However, wooden seawalls are not as strong as other materials. Timber can suffer from rot and infestation in addition to erosion unless properly waterproof-sealed and treated with preservatives. With proper maintenance though, a wooden seawall can last for decades and avoid erosion.
Concrete is one of the most durable construction materials out there. Seawalls built with concrete are anticipated to last over 20 – 30 years before requiring any maintenance or repair work. There are even structurally reinforced concrete walls that are almost a century old. Clearly, concrete seawalls have earned their place as some of the most effective structures for coastal defense.
Furthermore, concrete can be designed in a variety of forms for aesthetically pleasing results. Investing in a custom-designed concrete seawall not only protects your property, but also substantially increases its resale value.
In this form of coastal defense, large round pebbles are placed on a mound or sloping surface to be at an angle to the water. They may be loosely arranged in a cobblestone heap or combined with mortar to provide watertight armor for the shoreline. Either way, they provide a solid defense for areas with low wave action.
If the underlying mound is elevated enough, revetments allow waves to dissipate with minimum erosion. However, loosely arranged cobblestones may not last long under high-energy waves.
Riprap is the most common type of seawall construction. This is a mound-type seawall consisting of varying sizes of stones mixed with concrete, limestone and granite. Like cobblestone revetments, it is highly effective in dissipating low-pressure waves in less demanding areas.
Rip rap may also be placed at the bases of old seawalls to serve as reinforcement to avoid erosion of your seawall. When used in this fashion, it can last longer and provide more effective protection than standalone mound-type seawalls.
Steel Seawall to Avoid Erosion
Steel is used to construct seawalls because this type of material is low maintenance. Industry experts believe that steel seawalls are the strongest. They are also the most versatile, since they have no height limitations unlike other types of seawall.
Installing a steel seawall can be quite expensive, but the investment is well worth the cost since steel is easy to maintain. With proper maintenance, steel seawalls rarely ever need repairs or replacement. Moreover, they are capable of providing protection equivalent to those made of concrete, yet requiring far less space.
The sole downside to steel is that it rusts. However, this can be checked by periodic coating with protectants, regular inspections twice a year, and servicing.
Vinyl Sheet Piling
Sheet pile seawalls easily deflect light to moderate wave action and protect the coastline from erosion due to storms. They are anchored deep underground and usually reinforced at the base with large rocks. Unlike more traditional materials such as steel, concrete or wood, vinyl technology is seemingly ageless and retains its appearance after several years.
Vinyl sheet piling is growing in popularity among owners of beachfront property because of its ease in installation, durability and resistance to UV radiation. Due to these factors, vinyl sheet piles are unarguably one of the most effective seawall construction materials.
Composite Seawall to Combat Erosion
Composite seawalls are fiber-reinforced polymers engineered to beat UV radiation and sustain their aesthetic appearance. Although not as strong as traditional materials, composite seawalls are still very durable and can withstand moderate wave action.
The primary advantage of this type of seawall is its versatility. For different sizes of coastline, your contractor will suggest composite seawalls. Though composite seawalls work best in smaller areas with low tidal impact. These seawalls are also the easiest to install, and make an excellent replacement for steel seawalls in colder climates
Seawall Contractors in Palm Beach County, Florida
If you need help choosing the right seawall to combat erosion our team is here to help. Consultation is key to making the right choice of seawall for your needs. That is why you need a reputable construction firm like Seaside Marine Construction to guide you. Click here to contact us.