Concrete is an incredible substance. It’s composed of numerous minerals and sediments such as lime, silica, calcium sulfate, alkaline, and magnesia. When mixed with water, concrete hardens into an ultra-strong, stone-like substance that’s been used to support human habitation for thousands of years. The earliest instances of humans using concrete date back to 1300 B.C., when Middle Eastern builders used a limestone compound to coat the outside of their homes. Today, concrete is a vital part of the modern construction industry, used in everything from home foundations to tables, chairs, and even roof tiles.
While concrete is undoubtedly useful, it isn’t foolproof. It’s durable and can support tons of weight, but it’s a porous material composed of countless small holes. As a result, concrete is prone to cracking and breaking from an effect called the freeze-thaw cycle. This article explains how normal rain and weather changes can result in serious foundation issues and the steps you can take to prevent this type of damage.
What Is the Freeze-thaw Cycle?
The freeze-thaw cycle, also known as frost heave, is created when water freezes and thaws, expanding and contracting within structures. When water drops below 32°F, it expands by 9%, creating pressure on anything surrounding it.
When water seeps into cracks or other openings in structures, then freezes and expands, it causes those openings to widen, causing damage. Over time, the wider openings lead to more water finding its way into structures, resulting in a slow but exponential wearing down of their integrity and stability.
The freeze-thaw cycle can affect many home structures, including gutters, utility lines, foundations, walls, and soil. Freeze-thaw cycles often occur during the winter, when freezing temperatures give way to heat waves, melting the snow temporarily, only to freeze over again once the wave fades. The faster this temperature adjustment occurs, the more intense the cycle, causing more severe structural damage.
Any location with low-temperature winters can experience a freeze-thaw cycle. However, locations with harsher winters or that experience frequent temperature fluctuations, like the Northeast or alpine regions, will experience more damaging cycles. Evidence has also shown that climate change has made freeze cycles more damaging for certain locations. As winter weather becomes warmer, water thaws more frequently, increasing the number of temperature shifts in the cycle.
How Does Freeze-thaw Damage Concrete?
Concrete is a porous substance that’s full of countless amounts of tiny pits and cracks. Over time, water eventually widens these cracks, resulting in chips, fissures, and other minor structural failings. These openings can widen into more serious cracks if not addressed, patched, and remediated early on. As a result, any structure exposed to outside elements experiences freeze-thaw damage, including your driveways, walking paths, patios, and foundations.
Two kinds of freeze-thaw damage can manifest in concrete: surface spalling and internal cracking. Here’s some background on each:
- Surface spalling — This damage results from water accumulating and creating surface cracks to the depth of the water’s penetration. Effects include chipping and flaking of wall surface layers, exposing underlying aggregate and rebar support.
- Internal cracking — Unlike surface spalling, internal cracks can originate from within the concrete. During the mixing process, small pockets of air or water can form within the concrete that widen and break outward when exposed to freezing temperatures.
How To Prevent Freeze-thaw Damage for Foundations
Unfortunately, there is no way to prevent freeze-thaw damage. However, you can mitigate its impact and patch the damage it creates. Your best options include the following:
Keep Foundation Dry
Keeping your foundation dry and devoid of excess moisture is important for multiple reasons, including reducing freeze-thaw damage. The best way to keep your concrete dry is to ensure that your gutters, downspouts, and other water drainage systems are properly working. These systems keep water flowing away from your home and prevent the buildup of moisture around the foundation. Investing in good basement waterproofing measures like sump pumps can also help, especially in areas prone to flooding.
Control Lawn Moisture and Use Smart Landscaping
Regulating lawn moisture reduces freeze-thaw damage and soil freezes while helping prevent hydrostatic pressure buildup. You can control your lawn moisture by not overwatering, ensuring the slope of your property leads away from your home, and installing drainage systems.
Have Foundation Inspections
Foundation inspections allow you to spot early warning signs from freeze-thaw cycles and other foundation problems. We recommend that homeowners get their home foundations inspected once every five to seven years, but if you live in an area like the Pacific Northwest, you may need them more frequently.
Practice Proper Foundation Repair by Patching Cracks and Gaps
Freeze-thaw damage becomes more severe over time. Each year during the spring, we recommend giving your foundation a once-over to patch any visible cracks larger than a quarter of an inch. Waterproof silicone caulking is the best material for repairing this kind of foundation damage. Patching these foundation cracks slows down the damage from the freeze-thaw cycle and helps keep out pests like ants, cockroaches, and spiders.
Avoid Overusing Ice Melt
You should also be wary about overusing ice melt around the base of your home. While snowmelt can help remove slick surfaces, it also artificially creates more freeze-thaw cycles by temporarily melting the ice and snow. As the ice melt wears off and the now-liquid snow re-freezes, this creates more cycles than normal and potentially exacerbates already existing damage.
Final Frosty Thoughts on the Freeze-thaw Cycle
The freeze-thaw cycle is a creeping menace for homeowners across the country. As water seeps into the porous sections of your foundation, walkways, crawl space, and driveway, it slowly breaks down structural integrity. While impossible to entirely prevent, you can hold off freeze-thaw damage by keeping an eye out for any cracks and repairing them promptly, which can extend the life of your foundation.
