Revamp Your Concrete Patio: A Guide To Repainting

Painting a concrete patio is a great way to freshen up your outdoor space without breaking the bank. It's a DIY-friendly project that can transform the look of your patio, but it requires careful preparation and the right tools to ensure a long-lasting finish. In this guide, we'll cover everything you need to know about repainting your concrete patio slab, from choosing the right paint to achieving a smooth and durable finish. So, whether your patio is looking a little tired or you just want to give it a style update, read on for a step-by-step guide to achieving a professional-looking result.

Choose the right paint

Choosing the right paint is crucial to the success of your concrete patio repainting project. Regular exterior paint will likely crack and peel off soon after application. You need to use paint that is specifically designed for outdoor concrete patios and can resist various elements.

There are several types of paint that will work for your outdoor concrete patio:

• Concrete paints that contain sealants or waterproofing features. This is a good choice because it's specifically designed for outdoor concrete and can resist various substances and elements.
• Latex, water-based, or oil-based exterior paints designed for floors, patios, or porches. These paints are designed for exterior use and can withstand foot traffic.
• Masonry paints that contain added binders and epoxies. While this type of paint may bond well with the concrete, it may not protect your concrete from the elements.
• Garage floor coatings with colourful additives to protect and decorate at the same time.

When choosing a paint, also consider the colour of the exterior of your house and your patio furniture. Take colour swatches with you to the paint store so you can compare your existing decor with your paint choices.

Prepare the concrete

Preparing the concrete is the most important step in repainting your patio slab. Here's a detailed, step-by-step guide to ensure your concrete is ready for a new coat of paint:

Clear the Surface

Start by removing all furniture, decorations, plants, toys, and any other items from your patio. You need a completely clear surface to work on, ensuring that your patio is cleaned and painted evenly. Cover any plants and landscaping near the patio with tarps to protect them from cleaning solutions and water runoff.

Repair Cracks and Fill Holes

Concrete slabs can develop cracks and holes over time. Before repainting, it's essential to repair these imperfections. Use a wire brush to clean out the cracks, and then fill them with masonry crack filler or cement filler. If the crack is deep or wide, fill it in layers, allowing each layer to dry before applying the next. This will ensure a smooth and even surface for painting.

Remove Moss, Roots, and Vines

Pull out any moss, roots, or vines that have grown on the concrete surface. If you have a pressure washer, use it to remove stubborn dirt and debris effectively. If not, you can rent or borrow one or opt for manual removal and then sweep and hose down the patio.

Clean the Concrete Surface

Concrete can absorb and trap dirt, grease, and stains. To ensure your paint adheres well and lasts longer, deep clean the concrete. Use trisodium phosphate, muriatic acid, or phosphoric acid to scrub the surface. These products will help remove old paint and prepare the concrete for the new coat. Remember to wear protective gear, including rubber gloves, eyewear, masks, and rubber boots, when working with these strong chemicals.

Flush the Surface

After cleaning, use a power washer to flush the surface and remove any remaining debris, old paint, or efflorescence (a whitish salt deposit common on concrete). If you used an acid solution, neutralize the pH by sprinkling baking soda over the surface before rinsing. Ensure that you rinse thoroughly until no chalky powder remains on the concrete.

Test for Moisture Content

Concrete is porous and absorbs moisture, which can affect the paint's adhesion. To test if your concrete is ready for painting, tape down an 18-inch by 18-inch square of aluminium foil or thick plastic to the surface. Wait 16 to 24 hours, then check for condensation or moisture underneath. If the concrete is damp, wait for it to dry completely before proceeding.

Choose the Right Paint

Not all paints are suitable for concrete patio slabs. Opt for concrete paints with sealants or waterproofing features designed to resist water, salt, oil, and grease. Latex, water-based, or oil-based exterior paints designed for floors, patios, or porches are also good options. Masonry paints with added binders and epoxies can be considered, but they may not offer the same protection against the elements.

Consider Using a Primer

A concrete primer is not mandatory but highly recommended. It will even out the porous concrete surface and improve paint adhesion. Look for an exterior-grade concrete, masonry, or bonding primer and allow it to dry for at least eight hours before painting.

Determine Paint Quantity and Gather Tools

Calculate the square footage of your patio by multiplying the length by the width. This will help you determine how much paint you need, considering the manufacturer's coverage recommendations. Gather your tools, including brushes, rollers, extenders, masking tape, and tarps, before you begin painting.

Protect Surrounding Surfaces

Use masking or painter's tape to line the surfaces adjacent to your concrete patio, such as deck edges, exterior walls, doors, and windows. This will prevent accidental paint splatters and ensure a neat finish.

Choose the Right Day

Pick a dry day for painting, preferably with no rain in the forecast. An ideal temperature for outdoor painting is around 50°F (10°C). Ensure the concrete is completely dry before starting the painting process.

Prime the concrete

Priming Your Concrete Patio Slab

Priming your concrete patio slab is an essential step in the painting process. It will ensure the paint adheres properly, looks better, and lasts longer.

Clean the Concrete

Before applying primer, it is important to thoroughly clean your concrete slab. Small pores in the concrete can hold large amounts of dirt, oil, and debris, which can make it difficult for the primer and paint to adhere. Use a pressure washer, concrete cleaner, scraper, scrub brush, or soap and warm water to clean the slab. Remove any efflorescence, a white powder that can come out of concrete, as well as any old paint, grease, and stains.

Repair the Concrete

Before priming, repair any cracks or crevices in the concrete. Use an angle grinder to smooth out rough spots and fill in any large gaps with repair cement or concrete. Remove any loose or brittle areas to ensure your freshly painted concrete doesn't start breaking apart.

Choose the Right Primer

There are several types of primers available for concrete, including alkyd/oil base, acrylic/latex, and tinted shellac. For exterior applications, a water-based or acrylic primer is recommended as it will soak into the concrete better than an oil-based primer, creating a stronger bond. For interior applications, a universal primer can be used, but a primer specifically designed for concrete will yield better results.

Apply the Primer

Use masking tape to protect the edges around your patio and any areas you don't want to paint. Then, follow the instructions on your chosen primer and apply a thin, even layer to the concrete. Allow the primer to dry completely before moving on to painting.

Tips

• If you're painting indoor concrete, consider sealing it in addition to priming to provide extra protection against water.
• Use a good-quality roller with a thick nap to apply the primer. The roller should be thick enough to get into all the cracks and crevices of the concrete.
• Make sure to get good coverage with your primer coat. When complete, you shouldn't see any of the underlying colour showing through.
• For small cracks and pores, use a brush to ensure the primer gets into all the spaces.

Apply the paint

Now that your patio is primed and ready, it's time to apply the paint. Here's a step-by-step guide:

• Pour the paint into a paint tray: This will make it easier to coat your brushes or rollers evenly, ensuring a smooth application.
• Paint the edges: Use a smaller paintbrush to apply paint around the edges, joints, or any areas that are too narrow for a roller. Be careful not to get paint on adjacent walls, decks, or windows.
• Apply the first coat: Choose a starting point, such as an interior corner, and work your way outwards. Don't paint yourself into a corner! Use even brush or roller strokes to apply a thin, even layer of paint. Attach your roller or brush to an extender to avoid back and knee strain.
• Let the first coat dry: Concrete paint can take six or more hours to dry, so check the manufacturer's recommendations.
• Apply additional coats: Depending on the desired colour depth and the paint's coverage, you'll likely need two or three coats. Apply each new coat in a different direction to ensure even coverage.
• Allow the paint to dry and cure: While you may be able to walk on the patio after 24 hours, it's best to wait about seven days before replacing furniture to avoid any potential damage.

Tips for painting:

• Work during dry weather conditions, ideally with mild temperatures around 50°F (10°C).
• Use a roller or brush extender to make the job more comfortable and reduce strain on your body.
• If using a brush, ensure it's large enough to cover a significant area before the paint dries.
• Always follow the manufacturer's instructions for drying times and application methods.

Seal the concrete

Sealing your concrete patio slab is an important step to ensure the longevity of your patio and prevent water damage. Here is a detailed guide on sealing your concrete:

Clean and Prepare the Concrete Surface

Start by removing any furniture and plants from the patio. Then, use a pressure washer to thoroughly clean the surface, removing any dirt, stains, or old paint. Ensure you use a pressure setting below 1,750 PSI to avoid damaging the concrete. If there are any cracks or holes, fill them with a concrete crack filler or hydraulic cement to create a smooth and even surface.

Apply an Etching Solution

Once the concrete is clean and dry, apply an etching solution to remove any salt deposits and prepare the surface for painting or sealing. DRYLOK® Concrete and Masonry Liquid Etch & Clean is a recommended product for this step, as it is safer than highly corrosive and reactive muriatic acid.

After the etching solution has dried, it's time to seal the concrete. Choose a concrete sealer suitable for exterior use, such as DRYLOK® sealers and waterproofers, which can resist moisture and increase the surface's longevity. Follow the manufacturer's instructions for application, and allow the sealer to set for up to 24 hours.

Conduct a Moisture Test

After the sealer has dried, conduct a moisture test to ensure no trapped moisture remains. Tape a 12" x 12" piece of 3-mil plastic or aluminium foil to the surface, ensuring all edges are taped tightly. Wait 24 hours, then remove it. If the underside of the plastic or foil is damp, allow more time to dry and re-test until it is completely dry.

Apply a Concrete Primer (Optional)

If you plan to paint your patio, it is recommended to apply a concrete primer to improve paint adhesion and long-term durability. Choose a primer suitable for exterior concrete, such as DRYLOK® Latex Concrete Floor Paint, which is an all-in-one paint and primer.

Paint the Concrete (Optional)

Finally, if desired, apply your chosen paint specifically formulated for use on concrete. You may use a brush or a long-handled roller, depending on the texture of your patio. Allow the paint to dry thoroughly between coats, and apply at least three thin and even coats for the best results.

Remember to always refer to the manufacturer's instructions for the specific products you are using, as different brands may have varying recommendations.

Frequently asked questions