A seawall is a barrier that prevents beach erosion by acting as a line of defense by holding back water. Because it is built alongside water, it must withstand brutal conditions such as heavy loads, salt water, violent storms and insect infestation and constant pressure. This hard punishment often results in breaks in the wall, which must be repaired quickly to prevent erosion from further destroying the wall.
Remove old, broken or rotten boards, preferably in the fall when the water level is at its lowest. Mark the shoreline at eight foot increments for posts.
Dig holes for the posts. Plan for the posts to descend two feet into the soil. Fill each hole with six inches of concrete mix, then place the steel post, making sure it is level and straight. Fill to just beneath ground level with concrete mix. Allow the concrete to dry.
Measure and cut boards that run from post to post. Due to fluctuations in the terrain, each measurement may be slightly different. Measure and cut the boards one at a time.
Drill holes in each end of the board where the rebar is located. Slide the board into place, and fasten with washers and nuts. Trim off excess rebar with a metal saw.
Backfill the wall with gravel or crushed rock. Cover the lower front of the wall with stones or chunks of concrete.