How to Seal A Concrete Driveway
DIY Tips for Sealing and Repairing Concrete Surfaces at Home
Concrete driveways endure a lot over the seasons. Extreme fluctuating temperatures, oil stains, shovels, and the heavy weight of vehicles all take a toll on concrete driveways.
But with a bit of care and maintenance, you can protect your driveway year-round.
One of the best ways to protect your concrete from all this wear and tear is with concrete sealant. When applied properly, concrete sealant improves both the appearance and the durability of concrete.
You can prevent stains, mold, and cracking by staying on top of sealing concrete. And if your concrete already has cracks, you can easily repair cosmetic cracks in a driveway or walkway.
But do not attempt to repair cracks in your home’s poured concrete foundation. Foundation cracks are more serious and require professional assessment.
If your concrete is cracked, stained, or fading, it’s time for a repair and resealing, especially before the brutal forces of winter arrive.
Take some time to consider these tips for sealing concrete and to repair concrete slab cracks to keep your driveway, walkway, patio, or flooring in good condition to withstand all things thrown its way.
What Is the Best Way to Seal Cracks In Concrete?
When sealing cracks in concrete, you should first remove any debris and loose concrete with a screwdriver and then a wire brush. Afterwards, sweep the crack or blow it out with a leaf blower.
Next, fill the concrete crack with concrete repair caulk, such as polyurethane concrete sealant.
For cracks that are wider than ¼ inch, first push foam backer rod into the crack with a screwdriver to ½ inch below the surface, and then fill the crack with concrete repair sealant.
Do I Need to Use Concrete Sealer?
Concrete sealer is a protective coating that will keep your concrete in better condition for longer. It will protect your concrete from the elements and stains.
It’s much easier to clean de-icing salts, oil, and grease off a sealed driveway. However, you should avoid using de-icing salts on concrete since these chemicals will wear down the protective coating. Instead, use sand or kitty to gain traction on icy surfaces.
To start protecting your concrete as soon as possible, you should apply concrete sealer as soon as new concrete finishes curing.
Sealer will protect your concrete against various types of damage. Acrylic sealers protect concrete from the sun’s damaging UV rays, rain, mold, and mildew. These sealers also enhance the colours of decorative concrete while providing a matte or gloss finish.
Penetrating sealers, such as waterproofing sealers, create a hydrophobic barrier to prevent moisture and vapor. This is especially important to have during the freeze-thaw cycle since concrete is more prone to cracking if it absorbs water and the water freezes and expands.
Other penetrating sealers, like silicates, will actually strengthen the concrete by densifying.
For large driveways and parking lots, consider hiring professionals to repair and seal your concrete with asphalt.
How Do You Apply Sealer to Concrete?
Once your concrete slab has cured (after about 28 days) check the weather forecast for the next few days. You should seal concrete when it is warm and dry. The temperature should stay above 10˚C for 8 hours, and above 0˚C for an additional 24 hours.
Follow these steps to properly seal concrete:
Step 1: Thoroughly Clean the Concrete
Follow the cleaning instructions below and allow the concrete to fully dry before moving on to step 2.
Step 2: Use an Etching Solution
To ensure the sealer adheres well to the concrete, consider using an etching solution to open up the concrete. Follow the manufacturer’s instructions for the best application method.
Step 3: Apply the Sealant
In a well-vented area, apply a thin coat of sealant to the concrete using a roller or a sprayer. The application tool you use will depend on the type of sealant you’re applying, for example, water-based or solvent-based. Refer to the manufacturer’s instructions for suggestions.
Less is more when it comes to applying sealant, so always aim to apply a thin coat so it is more even.
Let the sealant dry for a minimum of two hours before applying a second thin coat. When applying the second coat, apply in the opposite direction (i.e. perpendicular, or a 90-degree (right) angle) from your first coat to ensure consistent coverage.
How Clean Does Concrete Need to Be Before Sealing?
Concrete should be thoroughly cleaned before sealing. Without a good cleaning, the sealer will seal any dirt and stains in the concrete, making them nearly impossible to remove. Also, sealer won’t adhere to most stains.
Use a cleaner to remove existing sealer and stains such as oil, grease, paint, mastic, mold, and mildew. The concrete cleaner you use will depend on the stain type. Once clean, use a shop vac to remove any leftover dirt, dust, debris, and moisture.
If you want to make sure your concrete is super clean, use a pressure washer with at least 3,500 psi and a 25-degree fan tip. Hold the pressure cleaner wand six to eight inches from the surface of the concrete and go over the concrete with slow, even sweeps.
Allow your concrete to dry for 24 hours before applying the sealer. During this time, fill any cracks you wish to repair in your concrete.
Smooth concrete repair sealant over any cracks with a putty knife and read the manufacturer’s instructions for the drying time.
How Long Before You Can Drive On Sealed Concrete?
The concrete sealant must be completely dry before you drive on it. It can take up to three days to dry. But to be sure, check the manufacturer’s instructions for drying times.
Can You Resurface Concrete?
You can use concrete resurfacer to resurface worn-out and spalling driveways, walkways, patios, and other concrete surfaces. Spalling refers to concrete that has pits and appears to be crumbling.
After a thorough cleaning, patch any spalled areas, filling in the pits with the resurfacer, and finishing with a trowel until smooth.
Once the patch is dry, you can resurface the concrete. If there are joints in your walkway, first fill these with peel-and-stick foam weather-stripping before resurfacing.
Mix and pour the resurfacer a little at a time, spreading with a trowel until even, smooth, and 1/8- to ¼-inch thick. For a slip-resistant finish, wait five minutes and then sweep a nylon-bristled broom across the surface, going against the direction of foot traffic. Let it dry for six hours before walking on it. Be sure to cover it up if it starts to rain!
How Do You Repair Concrete?
As mentioned above, there are several ways to repair concrete, depending on the damage. For cosmetic cracks, use concrete repair sealant and patching. But for deep cracks that go all the way through concrete, you will need to replace the concrete.
Contact your local concrete suppliers for help with repairs and advice for choosing the right concrete products for your home project. A bit of work can go a long way when it comes to protecting your concrete driveway year-round.