How to Prevent Concrete Cracking?
How to Prevent Concrete Cracking? You just invested thousands of dollars into a beautiful new concrete pathway. Fast forward one year, and spiderweb cracks are spreading across the surface like fault lines after an earthquake. Your heart sinks as you realize those cracks will only get worse with every freeze-thaw cycle Fredericton’s winters throw at them. Concrete cracking is one of the most frustrating problems property owners face across Canada, and it’s often completely preventable. The difference between concrete that lasts decades and concrete that cracks within seasons comes down to understanding what causes these failures and taking the right steps from day one. In this guide, you will discover exactly how to prevent concrete from cracking in Canadian climates. We’ll walk through the critical preparation steps, proper materials and techniques, ongoing maintenance strategies, and when it’s time to bring in professionals like Atlantic Brick and Stone. Whether you’re planning a new installation or trying to protect existing concrete, you’ll learn proven methods to keep your concrete solid for long time. What causes concrete to crack? Before you can prevent concrete cracking, you need to understand your enemy. Several factors work together to stress and eventually fracture concrete surfaces, and many of them are particularly harsh in Fredericton’s climate. Environmental factors top the list of concrete destroyers. Freeze-thaw cycles occur when water seeps into tiny concrete pores, freezes, and expands by roughly nine per cent. This expansion creates immense internal pressure that forces the concrete apart. When you combine this with extreme temperature fluctuations between summer heat and winter cold, your concrete experiences constant expansion and contraction that generates stress over time. Seasonal ground movement adds another layer of challenge as soil beneath your concrete shifts with temperature and moisture changes. Material issues create vulnerabilities from the inside out. When the water-cement ratio in your concrete mix is wrong, you end up with weak concrete that can’t withstand normal stresses. Low-quality aggregates (the sand and gravel in concrete) create weak spots throughout the material. An inadequate overall mix design sets you up for failure before the concrete even hits the ground. Structural problems beneath the surface cause just as many headaches. Insufficient sub-base preparation means your concrete sits on unstable ground. When soil isn’t properly compacted or contains organic material that decomposes over time, you get uneven settling that creates stress points. Foundation settling happens when the ground beneath concrete sinks unevenly, forcing the rigid concrete to crack as it tries to follow the movement below. Construction defects during installation doom even good concrete to early failure. Rapid drying during the curing process prevents concrete from developing its full strength. Improper finishing techniques can weaken the surface layer. Missing control joints (those intentional grooves you see in sidewalks) mean concrete cracks randomly instead of in controlled locations. Excessive loads stress concrete beyond its design capacity. Parking a heavy recreational vehicle on a residential driveway designed for cars creates point loads that can crack the concrete. Even repeated loads from delivery trucks can progressively damage concrete not engineered for that weight. Chemical exposure slowly eats away at concrete integrity. De-icing salts like calcium chloride and sodium chloride corrode concrete surfaces, particularly during winter months. Certain fertilizers containing ammonium nitrate or ammonium sulfate actually attack concrete chemically and should never be used near concrete surfaces. Atlantic Brick and Stone’s 15+ years of experience means we’ve seen every one of these failure modes firsthand. Our approach addresses each potential cause through careful sub-base preparation, quality materials, proper construction techniques, and comprehensive curing procedures that give your concrete the best possible start. How to prevent concrete from cracking? Preventing concrete cracks requires attention to detail at every stage of your project. From the ground preparation to the final curing steps, each phase plays a critical role in creating durable, crack-resistant concrete. Proper sub-base preparation The ground beneath your concrete determines whether it will last five years or fifty years. Think of the sub-base as the foundation for your foundation—get it wrong, and everything built on top is compromised. Start by removing every trace of topsoil and organic material until you reach stable ground. Topsoil contains roots, leaves, and decomposing matter that will break down over time, creating voids beneath your concrete. These voids lead directly to settling and cracking. Don’t cut corners here—dig down to solid, stable soil even if it means more excavation than you planned. Next, bring in well-compacted granular fill made from crushed stone. This material provides a stable, drainage-friendly base that won’t shift or settle. The key word is “compacted.” Loose stone will settle under the concrete’s weight and cause cracking within months. Professional crews use plate compactors or vibratory rollers to compress the stone in layers, typically compacting each 100-150 millimetre layer before adding the next. This creates uniform support across the entire area. Your sub-grade must be sloped properly to move water away from the concrete rather than letting it pool underneath. Water accumulation beneath slabs leads to erosion, freeze-thaw damage, and soil movement—all recipes for cracks. A slope of just one to two per cent (about 3 to 6 millimetres per metre) is usually sufficient to keep water moving. Thickness requirements vary by application: Residential driveways: 100 to 150 millimetres of compacted stone base Commercial applications: 200 millimetres or more for heavier loads High-traffic areas: Additional depth based on soil conditions Atlantic Brick and Stone conducts proper soil investigation and designs the sub-base to match your specific soil conditions and intended use. Cutting corners on sub-base preparation to save a few hundred dollars often costs thousands in repairs within just a few years. Optimized concrete mix design The concrete mix itself makes or breaks your project’s long-term success. Even perfect installation can’t overcome a poorly designed mix, while a properly formulated mix gives you significant insurance against cracking. The water-cement ratio stands as the single most critical factor in concrete strength. Too much water makes concrete weak, porous, and prone to shrinkage cracks. Too little makes









