Ice Can Damage Your Seawall—Stop It Cold In Its Tracks!
Take a look around in the winter, and you’ll start to see that how much of a destructive force the cold can be.
Water expands as it freezes and contracts as it melts, and you can see all sorts of structures getting serious damage from that process, from roofing to foundations. You can also see the damaging effects of this contraction and expansion in frost heaving, when concrete roadways crack and buckle as freezing temperatures reach groundwater deposits.
But one structure you may have not though about experiencing ice damage is the seawall you use to protect your shoreline from erosion.
Depending on the materials it’s made from and the conditions in your area, your seawall can be eroded and damaged by winter in all those same ways. And when the ice and snow start to melt in spring, they pose a whole additional set of potential problems.
So, how can winter damage your seawalls? How can it be prevented? And what should you do about it if there is damage?
How Ice Can Damage Your Seawall
Last year, a severe blizzard hit Boston, and two 80-foot-long sections of concrete seawall were smashed apart, unleashing floodwaters on the homes the seawall had been protecting. Photos show massive slabs of concrete from the seawalls flung across the residents’ yards.
A blizzard in your area may not be this extreme or cause this much damage, but it can still put a lot of strain on your smaller seawall and put it at risk of failure.
The next way that winter can harm your seawall is ice floes crashing and scraping against the seawall itself.
In winter, surface ice develops on the body of water that the seawall borders. Often this doesn’t pose too big a problem, but in the right conditions that ice can cause serious damage.
On temperate inland lakes like those we have here in the Chain o’ Lakes, there’s a particularly high risk during winters that are cold, clear, and have low snowfall. When the sky is clear and there isn’t snow packed on the surface ice, the ice is exposed to the sun’s radiation on sunny days. This can cause the ice to crack and spread apart, and ice on the surface to melt. Then, during the cold night, that melt water from the surface melt fills the cracks and refreezes, creating a cycle where the ice can continually expand and scrape against seawalls and shorelines.
Another way that ice can damage your seawall is in the spring thaw. Again, the rising temperatures cause surface ice to crack and spread apart in large chunks, and these ice floes can be slammed and scraped against your seawall by winds and waves. Residents of Auburn, NY saw this firsthand last year, when the thaw sent large ice floes crashing into a seawall at a local park. Sections of the seawall, which had stood for over a hundred years, were smashed apart, resulting in extensive damage.
Finally, there’s that same threat that affects roads and other structures that we described above: ground freezing and ice heaving. This is when water in the soil below a structure starts to freeze after the cold penetrates below the surface. A “freezing plane” forms, and this layer of ice has a drying effect which pulls more moisture to itself from the surrounding soil. This ice layer grows in the shape of a lens, pushing up on the soil and structures above itself. This can cause buckling not just on roads, but in your seawall, too, depending on the type of soil and the design of the seawall.
How to Prevent and Repair Ice Damage
So, if ice can cause so much damage to your seawall, what is there that you can do about it?
The first step is something that you should already be doing: regular seawall maintenance. You should already be regularly inspecting your seawall for potential issues and performing upkeep on your seawall as needed, but you should step it up and keep a closer eye on your seawall when ice is present.
Take the time to walk up and down the length of your wall checking for signs of trouble. These signs tend toward the obvious: cracks, gaps, leaks, etc. Any breach in the seawall is a way for water to get into the backfill and cause further damage. Get these repaired sooner rather than later, and you can prevent larger damage to the seawall.
It can also be useful to take a look at the surface ice out on the water. Is it cracked? Is there surface melt? Is there no snow accumulated on top of the ice? These can all be indicators that the ice could possibly come crashing into your seawall soon.
Another possible solution is to install a de-icer, such as an ice eater or bubbler. These ice removal devices are most often used to similarly protect piers from those same ice floes, so it may be useful to have a professional assess whether this would benefit your seawall.
If you’re just getting a seawall installed though, you have the opportunity to plan ahead with the design of your seawall. Have your property assessed, and make sure the climate is taken into account: when winter comes, will there be ice floes? And is this type of soil susceptible to frost heaving?
With this information in hand, choose your seawall accordingly. Steel and vinyl seawalls are the most resistant to the effects of ice. However, you also have to make sure that the pilings extend far enough down to go below the level of maximum frost penetration to prevent frost heaving from putting pressure on the seawalls from below.
When making these decisions, you want a qualified professional at your disposal. And if you need new seawalls installed, or existing seawalls repaired or maintained, there’s no professional you’d rather have than one of the experts from Seawalls Unlimited. We’ve been installing and working in McHenry, IL and the Chicago area for years—so give us a call at (815) 331-8830 and we’ll keep your seawalls standing strong this winter and spring.
2350 W. Rte. 120
McHenry, IL 60051