Sealing Concrete Patios: How Often Is Necessary?

Concrete is a durable and versatile material that is commonly used for patios. However, concrete is a porous material that can be damaged by water, stains, and foot traffic over time. To protect your concrete patio, you should consider sealing it. Concrete sealers act as a barrier to prevent moisture and stains from penetrating the concrete, which can help to extend the lifespan of your patio. The frequency with which you need to seal a concrete patio depends on various factors, including the type of sealer used, the amount of foot traffic, and the external conditions. On average, concrete patios should be resealed every one to three years to maintain their protective and aesthetic qualities.

How often to reseal a concrete patio

Concrete patios are a great, durable, and versatile choice, but they do need to be sealed and resealed to protect them from the elements and general wear and tear.

On average, concrete patios should be resealed every couple of years. However, this depends on several factors, including the type of sealer used, the weather, and the amount of foot traffic.

For example, concrete that is exposed to harsh weather conditions or heavy foot traffic may need to be resealed annually. On the other hand, concrete in a covered area with low footfall may only need resealing every five years or so.

There are a few tell-tale signs that your concrete patio needs to be resealed:

• The colour has faded
• The surface looks cracked or damaged
• The concrete has lost its shine
• The patio is absorbing water rather than repelling it

Resealing concrete is not a difficult process, but it is time-consuming and should be done properly to avoid further damage. Here are the steps to reseal your concrete patio:

• Clean the concrete thoroughly and allow it to dry completely
• If necessary, fill in any cracks and level uneven slabs
• Seal the seams between slabs and structures
• Apply a thin, even layer of sealer using a sprayer, brush, or roller
• Allow ample time for the concrete to dry (at least 24 hours)

Choosing the right concrete sealer

Type of Sealer

The four main types of concrete sealers are acrylic, polyurethane, epoxy coating, and polyaspartics. Acrylic sealers are the most common type as they are cost-effective, easy to apply, and suitable for both interiors and exteriors. They provide good protection from moisture and chloride penetration while allowing water vapour to escape. However, they may develop a yellow tint over time. Epoxy sealers, on the other hand, offer a thicker layer of protection and are highly water-repellent but are limited to interior use as they are susceptible to UV light. Polyurethane sealers provide a protective film that is thicker than acrylic but not as thick as epoxy. They are suitable for both interior and exterior applications and offer excellent abrasion and chemical resistance. Penetrating sealers, as the name suggests, penetrate below the surface of the concrete and are effective at repelling water and chemicals.

Application Method

Most concrete sealers can be applied using an HVLP or airless sprayer, or a lint-free paint roller. Epoxy sealers, however, require a different application method as they are a two-part product that must be mixed before application. They are typically spread with a notched squeegee and then smoothed with a lint-free roller.

Environmental Impact

It is important to consider the environmental impact of the sealer you choose. Solvent-based sealers, including solvent-based acrylics, release VOCs (volatile organic compounds) which can be harmful to health. Water-based sealers, on the other hand, emit little to no VOCs and are generally safer during application.

Durability and Maintenance

Consider how long you want the sealer to last and how much maintenance you are willing to do. Acrylic sealers typically last around 3 years before needing to be reapplied, while epoxy and polyurethane sealers can last much longer. Penetrating sealers may need to be reapplied every 1 to 10 years, depending on quality.

Aesthetics

Different sealers will give your concrete a different finish. Acrylic sealers offer a range of sheen options from matte to glossy, while epoxy sealers provide a thick, high-gloss finish. Penetrating sealers are usually invisible, preserving the original appearance of the concrete.

Climate

The climate you live in should also factor into your decision. In cold climates, silane or silane/siloxane blends are recommended as they hold up well against the abrasive effects of snow and ice. In warm climates, either a silane/siloxane blend or acrylic sealer will work well.

Cost

Finally, consider your budget when choosing a concrete sealer. Acrylic sealers are usually the most cost-effective option, while epoxy and polyurethane sealers tend to be more expensive.

In conclusion, there are several factors to consider when choosing the right concrete sealer. By taking into account the type of sealer, application method, environmental impact, durability, aesthetics, climate, and cost, you can make an informed decision that will protect your concrete patio or driveway for years to come.

Preparing the concrete for sealing

Clean the Surface

Start by thoroughly cleaning the concrete surface to remove any dirt, grime, stains, paint, mastic, or grease. Use appropriate substances to remove stubborn residues and follow up with a floor cleaner and water to mop the area. Ensure the patio is immaculately clean before proceeding.

Fill Cracks and Smooth the Surface

Once the patio is clean and dry, address any cracks or imperfections. Fill the cracks with an appropriate material, such as epoxy, to create a smooth and even surface. This step is important to ensure a uniform and consistent seal.

Test for Existing Sealant

If your patio has been previously sealed, you'll need to remove the old sealant before applying a new one. To check if your concrete has been sealed, pour a cup of water onto the surface. If the water beads and stays instead of soaking in quickly, it indicates the presence of a sealant.

Remove Old Sealant

To remove the old sealant, use an airless paint sprayer or a roller to spread a chemical stripper on the concrete, following the product's instructions. Use a long-handle scraper to remove the sludge produced and then scrub the floor with a mixture of water and trisodium phosphate. Ensure proper waste disposal of the old sealant mixed with the chemical stripper.

Allow Drying Time

After removing the old sealant, thoroughly dry the area for at least 24 hours. This step is crucial to ensure the surface is ready for the new sealant application.

Choose the Right Sealer

Not all sealers are created equal. Select a high-quality sealer that suits your specific needs, such as SEAL-ONCE® NANO+POLY, which offers advanced nanotechnology and polyurethane protection. Consider factors like UV protection, matte or glossy finish, and specific benefits like salt damage resistance.

By following these steps, you will effectively prepare your concrete patio for sealing, ensuring a durable and aesthetically pleasing result. Remember that a well-prepared surface is key to achieving a successful sealing project.

Applying the sealer

Sealing your concrete patio is a great way to protect it from stains, water damage, and weathering. It is a crucial step in maintaining its durability, appearance, and longevity. By applying a protective sealant, you create a barrier that shields your patio from damage.

• Start early in the morning or late in the evening to avoid peak sun hours. The cooler temperature will also help prevent air bubbles from forming in the sealer.
• Ensure your patio is immaculately clean and fully cured. Start with a pristine surface to ensure your sealant adheres correctly. Remove any dirt, debris, or loose materials using a broom, leaf blower, or pressure washer.
• Repair any damage to the patio. Inspect your patio for cracks, chips, or other forms of damage. Repair these areas using appropriate fillers or patching compounds.
• Allow sufficient drying time after cleaning and repairing. Give it ample time to dry completely, ensuring any moisture trapped within the surface evaporates.
• (Optional) Consider etching if you have a smooth and non-porous concrete surface. Etching creates microscopic pores on the surface to improve adhesion.
• Choose a high-quality sealer that is specifically designed for concrete patios. Consider factors such as durability, UV protection, and stain resistance when selecting a sealer.
• Apply the sealer evenly, working in sections to ensure thorough coverage. Use a sprayer for large areas and a brush for edges and detailed work. Avoid creating puddles by aiming for thin, even layers.
• Allow ample time for the sealer to dry before walking on the patio or placing any furniture on it. Follow the manufacturer's instructions for drying time.
• Apply a second coat if recommended by the manufacturer for added protection or enhanced appearance.
• Maintain your sealed patio by regularly cleaning it with mild detergent and water. Avoid using harsh chemicals or abrasive cleaners that can damage the sealant.

By following these steps, you can effectively seal your concrete patio and protect it from the elements, ensuring its longevity and maintaining its appearance.

Drying and curing times

Drying Times

Concrete typically takes 24 to 48 hours to dry before it can be walked on. This timeframe can be affected by various factors, such as the water-cement ratio, ambient temperature, and humidity. The ideal temperature for concrete to dry is between 50°F and 80°F, with a relative humidity between 40% and 60%. If the temperature is too hot, the concrete may dry too quickly and crack; if it's too cold, it may take a long time to dry.

Curing Times

Curing is the process of allowing concrete to reach its full strength. It usually takes about 28 days for concrete to fully cure. During the first week of curing, it's crucial to maintain the proper temperature and moisture levels. This can be achieved by using curing methods such as sprinkling with water, spraying and fogging, concrete formwork curing, ponding and immersion, or covering with sand, sawdust, or soil.

The curing time can be affected by the concrete mixture and environmental conditions. Fast-setting concrete mixes will have shorter curing times, while standard or high-performance mixes will take longer. The weather conditions, particularly temperature and humidity, also play a significant role in curing times.

It's important to note that sealing a concrete patio should only be done after the concrete has fully cured. Sealing too early can trap moisture and extend drying times. Additionally, it's recommended to clean the surface thoroughly before sealing to ensure a pristine finish.

Frequently asked questions