Seawall Material & Cost Comparison

There are many materials traditionally used for building seawalls, bulkhead walls, lake walls, retaining walls and many other wall applications.   The introduction of the Truline wall system has been revolutionary, combining proven strong materials with reliable vinyl protection, to build the ultimate wall.  Here we will explain the differences in seawall materials and costs below.  Most other types of wall applications have the same pros and cons.  Materials that have been used and available on the market include:

  • Truline hybrid system
  • Concrete panels
  • Steel sheet pile
  • Single composite sheet pile
  • Single vinyl sheet pile
  • Aluminum sheet pile
  • Wood

Concrete Seawall Panels

Concrete panels obtain their strength from the concrete and steel-rebar.  The strength of the concrete used to build the panel can vary as well as the steel-rebar.  The engineer will specify the strength of the concrete and rebar and the length of the panels.  Most are usually "pre-cast" and must be transported and moved to the job site.  Concrete panels are usually made in standard sizes and are either 6" deep or 8" deep. 

  • 6" deep panel (most residential projects) - usually 5 feet wide and the length is 10, 12, 14 or 16 feet long
  • 8" deep panel - the width varies from 3 to 5 feet wide and the length is over 16 feet long

What are the top 5 challenges of concrete seawall panels and how does Truline solve them?

  1. Concrete panels have surface rust, corrosion, fracturing and spalling. When this happens, the strength of the wall is degrading and quickly in harsh saltwater environments.   With the Truline system, the strength of the wall is protected for the long-term by its dual-interlocking vinyl form which encases or protects the concrete and steel rebar. 
  2. Concrete panels are very heavy, big and difficult to install in tight or small spaces.  They require heavy equipment all of the time for transport and installation, causing costly tear-up.    The Truline solution is modular, flexible and versatile with its pour-in-place system.  It makes it easier to install in tight or small spaces and reduces the need to remove docks, boat lifts, or structures that would need moved for heavy equipment to install concrete panels.  Truline parts can even be hand-carried.
  3. Concrete panels have soil erosion through their single joints.  When this happens, it is not retaining or protecting the property.    Truline forms are dual-interlocking throughout including corners and turns and are made to custom lengths so property is protected.
  4. Concrete panels are difficult to cut or make turns and curves.    Truline modular vinyl forms are easier to cut than 6" or 8" concrete panels.  This reduces time and cost when holes need to be cut for pipes or other features.  In addition, Truline can easily make smooth, flat turns and curves. 
  5. Concrete panels are difficult and costly to install in rocky soil conditions.  A trench must be dug in the rock to install large panels.    The Truline system can be installed with the pin pile method into rock.  This pins the wall into the rock.  

Steel Sheet Pile

Steel sheet pile is an antiquated technology for the corrosive marine environment.  Steel is problematic in harsh salt water.   Steel can be expensive and the strength of the steel sheet pile is in the steel and shape, which can vary. 

What are the top 4 challenges of steel sheet pile and how does Truline solve them?

  1. Steel sheet pile is heavy and requires large equipment for installation.   Truline modular parts can be hand-carried to the job site.  Installation of the Truline wall system does not require large equipment and can be installed in tight spaces.
  2. Steel sheet pile requires annual maintenance in salt water due to corrosion.  A new marine coating must be applied in the splash zone every 3-5 years.   The Truline wall system does not require maintenance. The vinyl form is corrosion resistant.
  3. Steel sheet pile has industrial appearance.   The smooth, flat Truline vinyl form surface is aesthetically-pleasing and will not corrode or rust.
  4. Steel sheet pile is usually on the high end of the project cost due to equipment requirements.   Truline can be installed from the water or land and with standard installation equipment.  Installing Truline provides low-impact construction so there is less tear-up and less clean up costs.

Single Composite or Vinyl Sheet Pile

There are many manufacturers of single corrugated or "flat" vinyl or composite pile sheets.  All of these products obtain their strength from the vinyl or composite sheet and possibly the installation method.  The reason people call it "single" is because there is only one side and one lock, unlike the Truline form that is "double-walled" or "dual-interlocking".  Single vinyl or composite sheet pile has been on the market for over 30 years.  

What are the top 6 challenges of single vinyl sheet pile and how does Truline solve them?

  1. Single vinyl sheet pile has only one lock to rely on.   The Truline system does not compare to single sheet pile because Truline is a system to build a steel-reinforced concrete wall encased and protected by a double-wall, double-locking vinyl sheet pile form. 
  2. Single vinyl sheet pile strength is based on vinyl strength.   The Truline system strength is based on the steel rebar and concrete wall inside the vinyl sheet pile form.  
  3. Single vinyl sheet pile "creeps", which is deflection over time, because there is nothing "holding it up".   Because Truline is a cast-in-place steel-reinforced concrete system, the vinyl form does not "creep".
  4. Single vinyl sheet pile walls usually require wales for support to be added when a concrete cap is applied.   A Truline wall can usually be installed up to 16 feet exposed without adding the cost and industrial appearance of wales.  Plus, engineers can design with different strengths of concrete and rebar for each specific job site.
  5. Single vinyl sheet pile walls usually "walk" while driving in the ground.   Because the primary Truline U-Channel part is a box shape when connected, it drives straighter.  In addition, for sheets longer than 20 feet, a mandrel can be placed inside the Truline forms to drive the sheets.  
  6. Single vinyl sheet pile walls are usually designed with "theoretical" value specifications.   Truline specifications are based on actual values from actual testing, providing engineers with design confidence. 

Aluminum Sheet Pile and Wood Options

Aluminum sheet pile and wood walls are installed in various applications.  Typically, they cost less than the other options and are short-term solutions for water applications.  Marine borers wreak havoc with wood walls.  

Seawall Cost Comparison

Seawall material costs vary and typically the most expensive is steel and the least expensive can be wood.  The materials used for a project depends on a lot variables but one of the biggest factors is exposure height.  Exposure height is the distance from the soil to the top of the wall.  In other words, the wall that is "exposed" and not penetrated into rock or soil. 

It is impossible to provide a proper quote over the phone for a seawall construction project because there are so many variables that go into it and it varies by geography as well.  Each project must be reviewed in person by a contractor or engineer and we always recommend a soil report.  Some of the factors that go into a seawall construction quote include: 

  • All materials
  • Labor
  • Overhead (insurance, license, etc.)
  • Permits
  • Engineering 
  • Soil report
  • Soil conditions
  • Install from water or land
  • Anchor requirements
  • Upland structures 
  • Remove of old wall, if needed
  • Ability to get to job site
  • Equipment requirements

To help guide in seawall material choices and costs, the chart shows the materials used for the different exposure heights, typically for residential and commercial seawalls.  

Seawall material and cost comparison chart

Build your wall right the first time with the Truline system

Proven strength.  Actual specifications.  Long-term performance.  Refined aesthetics.