Aluminum seawalls resist corrosion well. However, waters with extremely low pH, or acidity, may contribute to the corrosion process. Aluminum’s lightweight quality may not be sturdy enough for a tall wall design or installation into a hard surface.
Vinyl or Plastic
Relatively new to the seawall material industry, vinyl or plastic has a longer lifespan than steel, possibly lasting more than 50 years. Unlike the other seawall materials, vinyl/plastic colors can be chosen for an aesthetically pleasing appearance. But, like aluminum, vinyl/plastic has height limitations and cannot be driven into hard surfaces.
Concrete seawalls are extremely strong, lasting more than 30 years. However, the concrete seawall structure must be specifically designed for a concrete installation, taking curing times and wall angles into consideration for the best protection against the ocean’s wave forces. Contractors should note the correct aggregate mixture for exposure to marine elements before pouring the concrete. Additionally, concrete may need maintenance, filling in cracks and holes from natural decay from ocean exposure.
Wood, offers a low-cost initial installation cost. Timber seawalls consist of multiple, vertically placed log piles, covered with wood planks and sheets. However, the timber has height limitations for high-surf applications. Typically, this seawall type is beneficial for waterways extending into the land from the ocean, avoiding the ocean’s strongest wave action. Timber seawalls are also prone to rot unless the timber is treated with a preservative. Additionally, timber installation may have difficulties if the ground is too hard.
The best material for a seawall depends on many factors, from average ocean wave height to proximity to the water. Each beach side development contractor should observe and record the needs of a particular region before deciding on a seawall design and material.