If the shoreline along your waterfront property is in need of a seawall, this article will be of interest to you. There are many different types of seawalls currently offered for install along most waterfront homes. You might be thinking “are these types of walls designed to protect your land against water (wake) and ice pressure”? The answer is no. Some contractors will tell you “yes” to get a sale, but physics will prove the answer to be ”no”.
There are two types of seawalls on the market designed to protect your shoreline effectively against areas with moving water and ice, vinyl piling seawalls and steel piling seawalls. Both of these walls consist of interlocking pilings driven into the ground, which makes them effective against water. When installed properly to the correct depth washout under and behind the wall is non-existent / along with heaving of the pilings from ground frost. There are pros and cons to both of these types of seawalls.
Vinyl seawalls consist of driving 18” width by 1/4” thickness vinyl pilings into the lake bed. This seawall is most commonly capped off with a treated lumber double wale and top board. The tie back system consists of 5/8” diameter threaded rod tied back to a 5 – 9′ depth structural I-beam anchor. The pros of vinyl seawalls include: no rusting or corroding of the pilings, 3 color options, and ideal for mucky soil conditions along some shorelines due to its light weight. The only con for vinyl seawalls is that they are designed for low ice pressure areas. This limits them to areas with no previous signs of ice damage and smaller waterways like canals.
If you have a tall seawall that calls for large amounts of backfill I would not recommend a vinyl seawall. Last but not least, most customers would like their seawall to be maintenance free. The treated lumber cap system attached to the top of a vinyl wall calls for normal maintenance such as staining or sealing with a treatment. Most vinyl manufacturers offer a no maintenance aluminum capping system typically available at a higher cost, ask your installer for details.
Now let’s talk about steel seawalls. This seawall consists of driving 18” wide pilings of 8 or 5 gauge (just under 1/4” thickness) solid steel into the lakebed and capped off with angle iron. The angle iron is then properly welded directly to each piling for a secure attachment. Make sure your installer does not torch holes in the metal and then bolt the angle iron to the pilings. This will cause problems within future years due to ice pressure bursting these bolts through the torched holes – freeing any attachment between angle iron cap, wale, and pilings.
The tie back system for this wall consists of 3/4” diameter threaded rod tied back to a structural I-beam anchor. The pros of this wall include: There is no maintenance required, it’s extremely durable, it’s designed for any type of ice pressure & sand backfill pressure/weight, and comes in two different types of metal. Steel seawalls come in black steel (regular raw steel) and galvanized steel (gray color steel). While black steel pilings will naturally oxidize and turn a brown, galvanized steel pilings wall holds their dim gray color. The cons of this wall include: In mucky soil type conditions, a longer piling will be needed to compensate, which will bump up the cost. Eventually, over the course of 30 to 60 years, this wall will corrode and rust at the high water line along the wall.
You have just learned the pros and cons of vinyl and steel seawalls. Throughout each year seaside seawalls installs many stone and and 3000# interlocking block as well. These type walls are attractive to many waterfront property owners along shoreline areas with low to moderate ice pressure.
Our most popular selling seawalls are steel followed closely by vinyl walls as they are slightly more cost-efficient. Which wall will fit your waterfront property conditions? For a free estimate, give us a call or inquiry and we will be happy to meet with you and discuss the future of your shoreline.