How to Ensure Proper Concrete Curing

Keep slab surfaces moist to prevent cracking.

Concrete curing is a process in which the cement and the water in concrete bond and harden through a chemical reaction called hydration. As they bond, the cement and water bind the aggregate and the sand to form a strong foundation structure. Proper curing is critical to the strength and durability of concrete.

Hydration

When a slab-on-grade foundation is curing, it's important to provide enough time for hydration to take place. Hot, dry conditions make water evaporate more quickly from the slab surface, which can cause concrete to harden more quickly, ultimately leading to a weaker material that's at greater risk of curling and cracking. The surface of the slab must be kept moist to prevent water from evaporating too quickly. Inadequate hydration reduces the slab foundation's strength, durability, impermeability, resistance to abrasion, and resistance to freeze-thaw cycles.

There are several ways to keep the slab surface moist during the curing process. One method is to apply curing blankets for a minimum of three days. Curing blankets are burlap sheets that cover the slab. The sheets should be wetted periodically to keep the concrete surface moist. However, they shouldn't be applied until the concrete has cured enough to resist surface damage.

Slab Curling

If the slab cures unevenly, it can result in a phenomenon called slab curling, in which the slab surface cures faster and therefore shrinks more quickly than the slab core. When the slab surface shrinks and pulls inward, the slab tries to curl upward and usually cracks instead.


Often, when weather conditions are hot and dry, excess water is added to the mix to make it easier to work with and to extend the working time. However, the excess water can cause the slab to curl unevenly and increase the likelihood of slab curling. An effective way to reduce the water content while maintaining workability is to add a plasticizer to the mix. Plasticizers increase the strength, fluidity and workability of the concrete mix without having to add water.

A proper curing process leads to a slab-on-grade foundation that's strong, durable and wear-resistant. Curing helps concrete attain its optimum strength, maximizing the foundation's life span.

Keep Reading

Next Up

How to Build a Concrete Fireplace Hearth

Carter builds a new concrete hearth to update an old 1950s fireplace.

How to Properly Paint Your Home's Exterior

Give your house a fresh, updated look with exterior paint.

How to Build a Wood Pergola

Pergolas provide some much needed shade from the summer sun. Learn how to build a pergola with these step-by-step instructions.

How to Build an Outdoor Pizza Oven

Add a wood-fire pizza oven to your outdoor kitchen. Learn how to create the base and install it with our step-by-step DIY guide.

How to Build a French Drain

If you're having problems with standing water in your yard or a leaky basement, improper drainage is the culprit. Fix your water drainage issues once and for all by adding a French drain in just a few short steps.

How to Build an Outdoor Stacked Stone Fireplace

Add fireside ambiance to your backyard with an outdoor fireplace made with stacked stone.

How to Build a Home Theater

Want a movie-theater experience in your home? Learn how to build a home theater with step by step instructions from the pros at HGTV.com

How to Build a Gas Fire Pit

A DIY gas fire pit gives you opportunities to express your creativity. Learn easy options for building your own gas fire pit.

How to Build a New Fireplace Surround and Mantel

A dated fireplace is given a British Colonial look with the addition of staircase posts, molding and a coat of fresh paint.

How to Build a Toy Box Bench

Make a toy chest that doubles as a bench with these simple steps.

Follow Us Everywhere

Join the party! Don't miss HGTV in your favorite social media feeds.