Constructing a Seawall for Stability and Safety
Seawalls are vital for canal lots in Florida, preventing erosion and preserving property value.
Building a seawall in the canals of Cape Coral is a must if you want to build a canal-side home in Florida. The movie shows how the company Williamson & Sons builds them. The pure construction time takes 3 days. The workers have incredible skill in operating their machines.
Construction of our Seawall 2016
The video shows the typical process and the construction of our Seawall. The William & Sons team was very professional and well-rehearsed.
Building a sea wall: Procedure, construction stages and special features
The construction of a seawall on the canal in Cape Coral follows a clear, officially regulated process. Once the contract has been awarded, the contractor starts with surveying and permit approvals. The city prescribes specific engineering standards and inspections, which are described in binding municipal guidelines.
Preparation, baking, setting panels
Very early in the morning: the excavator driver clears the bank of all plants.
The working area around the shoreline is limited.
Finished shoreline
A crane brings the concrete segments…
…to the water.
The segments must be set precisely.
View from the other bank
Using a pontoon/workboat and excavator, the shoreline is first established and the working area created. At the same time, the future wall is being marked out, which the city will later control, including the cap alignment.
The concrete panels are now set in place. These are rammed into place in sections, aligned and brought up to height. They are installed fairly quickly using an excavator. Tie rods are then placed behind the wall and anchored in the load-bearing soil with anchor beams, so-called deadmen. This step is a separate inspection point for the city.
This is followed by the formwork & casting of the final edge. At the top, a reinforced in-situ concrete head (cap) connects all panels to form a continuous unit. The reinforcement, concrete quality, dimensions and details are standardized. After stripping the formwork, the finished, load-bearing end edge is obtained. The sea wall is now complete and the filling work can begin.
Backfilling & choice of material
Reinforcement and formwork for the Seawall
Anchoring in the ground
Alignment of the formwork
The concrete mixer needs a long “trunk”.
Concrete distribution for the completion of the Seawall
Finished concrete mass
finished Seawall
The soil is backfilled in layers with compaction, followed by the final inspection. With well-coordinated teams, the actual construction work on the water can be completed in just a few days. In our case, the actual construction time was 3 days. We were very impressed.
Which type of wall makes sense depends on the channel, load assumptions, budget and availability. In Cape Coral, the acceptable systems in the Seawall Engineering Design Standards are: Concrete and two vinyl varieties with a concrete core. These documents regulate the details, dimensions, reinforcement, anchoring and testing, which has a decisive impact on durability and insurance.
Due to the severe hurricanes Irma and Ian in recent years, the regulations have been raised considerably. As a result, the price of building a seawall on the canal has multiplied. In 2016, we paid $21,000 for our oversized 146-foot seawall. Today it would cost more than $100,000.
