How to Build a Seawall

A seawall is a great structure to build to protect homes and valuables situated near shores. The process is relatively simple and can be done by any one person having the right tools. However, the project will be finished must faster with assistance.


  • 4 ft long by 3 inches Metal pipe
  • Concrete mix
  • 2×10 lumber
  • Nuts
  • Silicone sealant
  • Washers
  • 4, ½ inch threaded U-shaped rebar


  • Jackhammer
  • Reciprocating saw


  1. Obtain the relevant permits from your local building authorities before attempting this project. Without permission, you may build a structure that conflicts with the building codes and regulations of your area.
  2. Have an inspector look over your home and the area in which you want to install a seawall to determine the feasibility of building one. Complete paperwork before starting construction.
  3. Set the posts at 8 feet intervals in their designated spot; start by excavating the area then set the posts in place. Position the rebar towards the water and align the posts at equal levels.
  4. Pour concrete mixture to secure the posts and leave for approximately 24 hours to cure and dry completely.
  5. Saw lumber pieces and affix them to the posts with washers and screws. Cut off any excess rebar with a saw and apply a sealant to cover it.
  6. Finish the wall by adding stones, rocks, and sand, in that order, over on the land side; add riprap to prevent corrosion of the structure.

Tips and warnings

  • Keep in mind the highest water levels when building the seawall or it will be a useless structure. Before you begin construction, ensure you are well informed on the tides around the area and the climate; consult a local expert for help with this.
  • The seawall can be built by one person however, depending on the size of the structure; assistance may be needed to aid in transporting and putting the walls in the right location.
  • Build seawalls during the summer months; the concrete will dry more quickly during good, warm weather. Also, stormy weather makes it difficult to construct a seawall, as the tides will be very high and make it impossible for you to work.
  • Though building a seawall is not hard, it will take time, so patience is required. For very large properties, it is best to hire the help of professionals to get the seawall built.
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