Curing of Concrete Explained: What It Is & Why It Matters

Concrete is one of the most widely used construction materials across Canada, valued for its strength, durability, and versatility. But there’s one crucial step after mixing and pouring that determines its performance: curing. The curing process ensures the concrete develops its full potential, and in this post, we’ll explain what it is, why it matters, and how it’s done.

What Is Concrete Curing?

In construction terms, curing refers to maintaining adequate moisture, temperature, and time conditions in freshly placed concrete so it can achieve its intended strength and durability.

Concrete is made up of cement, water, and aggregates (sand and stone). When water is added to cement, a chemical reaction called hydration begins. Hydration is what gives concrete its strength, but it takes time. If the concrete dries too quickly or is exposed to extreme cold weather, the hydration process can slow down or stop prematurely.

Curing ensures that hydration continues long enough for the concrete to reach the strength and hardness needed for the structure or surface to perform as designed.

Why Curing Is Important

Think of curing as “protective aftercare” for concrete. Without it, concrete is vulnerable during its most critical stage of development. Proper curing results in:

Increased Strength

Well-cured concrete can achieve up to 50% more strength than uncured or poorly cured concrete.

Improved Durability

Curing helps prevent surface defects, cracking, and scaling caused by premature drying or temperature swings.

Better Resistance to Freeze-Thaw Cycles

In climates like Toronto’s, where temperatures fluctuate, properly cured concrete is less likely to suffer from freeze-thaw damage.

Reduced Permeability

Proper curing makes concrete denser, which helps resist water penetration.

Enhanced Surface Quality:

It reduces dusting and surface wear, keeping the concrete looking better for longer.

Methods of Curing Concrete

There’s no single “best” curing method. The right choice depends on the project type, weather conditions, and available resources. At kreitmaker, our volumetric concrete delivery allows precise mix control on site, which can make the curing process more predictable by ensuring the right water-cement ratio from the start.

Here are the most common techniques:

Water Curing

This is the most traditional and widely used method. It involves keeping the surface of the concrete continuously moist using water. Curing with water usually happens in one of three ways:

• Ponding: Creating a shallow “pond” of water on the slab.
• Sprinkling: Using hoses or sprinklers to keep the surface wet.
• Wet Coverings: Applying burlap, mats, or fabric kept damp with water.

Membrane-Forming Compounds

Liquid curing compounds are sprayed or rolled onto the surface to form a moisture-retaining film. These are especially useful for large areas where continuous water curing is impractical.

Plastic Sheeting

Sheets of polyethylene are laid directly over the concrete to trap moisture and slow evaporation. This method works well in windy or sunny conditions.

Steam Curing

Used primarily in precast concrete production, steam curing accelerates the hydration process by applying heat and moisture in a controlled environment.

Internal Curing

In some mixes, lightweight aggregates pre-soaked in water are used to slowly release moisture within the concrete as it sets.

How Long Does Concrete Take to Cure?

Concrete doesn’t “dry”, it cures. And that process takes time. While concrete reaches its initial set within hours, full curing is much longer.

• Initial Set: Within 48 hours, light foot traffic is possible.
• Partial Strength: By seven days, concrete has typically reached about 70% of its designed strength.
• Full Strength: Most concrete achieves full strength at 28 days under proper curing conditions.

Factors That Affect Curing Time

Several variables influence how long concrete takes to cure:

Temperature

Warm weather accelerates curing, while cold weather slows it down. Extreme heat can cause rapid evaporation, requiring extra moisture control such as shading or misting. In colder months, insulation blankets or heated enclosures may be required to keep the curing process on track.

Humidity

High humidity helps retain moisture, while low humidity can speed up evaporation and increase the risk of surface cracks. In dry conditions, additional measures like continuous sprinkling, fogging, or applying curing compounds are often necessary to keep the surface moist.

Mix Design

The water-cement ratio, aggregate type, and additives all affect curing time and performance. A lower water-cement ratio generally produces stronger, denser concrete but may require more careful curing. Special admixtures can slow hydration or help the mix hold moisture, making curing easier under challenging site conditions.

Concrete Thickness

Thicker pours hold moisture longer, allowing hydration to continue steadily, while thinner slabs lose water quickly and may need extra attention. For example, thin sidewalks or decorative slabs often benefit from plastic sheeting or wet coverings to avoid premature drying.

Wind & Sun Exposure

Wind and direct sunlight can cause rapid surface drying, increasing the risk of cracking. Contractors often use windbreaks, shade cloths, or evaporation retarders to protect exposed concrete surfaces, especially in open or south-facing areas.

Curing Concrete for Real-World Projects with kreitmaker

From large commercial slabs to residential driveways, curing should be part of every project plan from the start. At kreitmaker, we work with contractors, landscapers, and homeowners across Toronto, Mississauga, Scarborough, Markham, Vaughan, and beyond to ensure the right concrete mix is paired with the right curing strategy.

Our volumetric concrete trucks deliver the exact amount of fresh concrete needed, mixed on site to your specifications. That means better control over water content and a better start to the curing process. Combined with expert advice, this ensures your concrete can develop the strength and durability it was designed for.

Final Thoughts

Curing might not be the most visible part of a concrete project, but it’s one of the most important. From achieving maximum strength to ensuring long-term performance, proper curing makes the difference between concrete that lasts and concrete that fails prematurely.

By understanding what curing is, why it matters, and how it’s done, contractors and homeowners alike can make sure their projects stand the test of time. At kreitmaker, we have been Toronto's trusted provider of mobile mix concrete delivery for over 20 years.

Contact kreitmaker today for premium concrete delivered across the Greater Toronto Area with same-day service six days a week. Let us help you get the right mix and the right curing so your concrete stays as strong and reliable as the day it’s poured.