Curing Concrete in High Winds: Best Practices for Southern California

Effectively curing concrete in high winds, common in Southern California, requires strategies to prevent rapid moisture loss from the surface, such as applying liquid membrane-forming curing compounds immediately, continuously wet curing, or covering the concrete with impervious sheets.

To cure concrete in high winds, quickly apply liquid membrane-forming curing compounds, continuously wet cure, or securely cover the surface with impervious sheets to prevent rapid moisture loss and cracking.

High winds, especially combined with the dry Southern California climate, can rapidly dry out the surface of freshly placed concrete, leading to plastic shrinkage cracking and reduced strength. To prevent this, your focus must be on maintaining moisture within the concrete for as long as possible.

Immediate Curing Methods to Combat Wind

The most effective way to cure concrete in high winds involves early and consistent application of curing agents or barriers. Each method aims to keep the concrete surface moist, allowing it to achieve its full potential strength.

Liquid Membrane-Forming Curing Compounds

Applying a liquid membrane-forming curing compound is often the most practical approach for flatwork like driveways and patios, especially in windy conditions. These compounds form a protective film on the concrete surface that significantly reduces evaporation. The best practice is to apply these compounds as soon as the surface sheen of the bleed water disappears. While effective, admixtures should not be used indiscriminately or viewed as substitutes for proper construction practices.

Continuous Wet Curing

Wet curing involves continuously keeping the concrete surface saturated with water. This can be achieved by using soaker hoses, sprinklers, or covering the concrete with water-saturated burlap or cotton mats. For this method to be effective, the surface must remain wet continuously. Any dry spots can lead to localized stress and cracking. This method is highly effective but can be labor-intensive and challenging to maintain in persistent high winds without specialized equipment to keep covers from blowing away. For more on this, see our article on Wet Curing Concrete in Hot Weather.

Impervious Sheets

Covering the concrete with impervious plastic sheets or curing blankets is another excellent way to combat wind. These sheets physically block the wind and trap moisture within the concrete. For this to work well, the sheets must be securely anchored to prevent them from blowing off or flapping, which can damage the fresh concrete surface. Overlapping seams and weighting the edges with lumber or sandbags are critical steps to ensure the covers stay in place.

> Pro Tip: In extremely windy conditions, consider using a combination of methods, such as applying a curing compound first, then immediately covering with securely anchored impervious plastic sheeting, to provide a double layer of protection against rapid drying.

Factors Influencing Curing in Windy Conditions

Several factors unique to Southern California's environment can intensify the challenge of curing concrete in high winds:

• Low Humidity: The region often experiences naturally low humidity, which, when combined with wind, dramatically accelerates evaporation from the concrete surface.
• Temperature Fluctuations: While Southern California is generally warm, significant temperature swings between day and night, especially in inland areas, can affect curing rates. Wind can exacerbate the effects of these temperature changes.
• Wind Duration and Speed: Santa Ana winds, for example, can be both strong and prolonged, making consistent curing efforts even more critical.

Common Mistakes When Curing in High Winds

• Delaying Curing Application: Waiting too long to apply curing compounds or covers allows the surface to dry out prematurely, often leading to plastic shrinkage cracks before curing can even begin.
• Insufficient Anchorage of Covers: Plastic sheeting or burlap not securely weighted down can blow off, exposing the concrete, or flap, causing surface imperfections.
• Intermittent Wet Curing: Allowing the concrete to dry out between periods of wetting during wet curing can be more detrimental than not wet curing at all, as it creates cycles of wetting and drying that cause surface stress.
• Ignoring Mix Design: While not a mistake in curing itself, choosing a concrete mix with a high water-cement ratio can make the concrete more susceptible to rapid drying and cracking in windy conditions. For projects requiring high strength, such as driveways exposed to deicing chemicals, a minimum specified compressive strength of 4000 psi at 28 days with an air content of 5% to 7% is recommended, which often implies a lower water-cement ratio mix.

To ensure the best outcome for your concrete project in Southern California's often windy conditions, it's essential to plan for robust curing measures from the start. Western Concrete consistently implements these protective strategies to deliver durable, high-quality flatwork and other concrete installations.

Consider calculating your material needs with our Concrete Project Calculator to help plan your project effectively.