Cement is a tough material for an outdoor patio, but common cement can look monotonous and out of place in a back or front yard. Although it is possible to paint a cement patio, it requires special care. Painting cement can cause some specific problems, but if you take the proper precautions, you can paint your patio without issues and you will not spend time or additional money.
- Clean your cement patio
Check the moisture content of the cement. Before painting the patio, first make sure the paint adheres. Cement is porous and absorbs moisture, but if your cement patio contains a lot of moisture, you will not be able to paint it until the moisture content is regulated.
- Take a square of aluminum foil or 45 by 45 inches (18 by 18 inches) thick plastic and glue the four sides, sealing the square to the cement with tape.
- Wait between 16 and 24 hours. Once this period has elapsed, carefully remove the square and check for condensation or moisture in the cement and the lower part of the square.
- Continue cleaning and painting if the area is dry.
Clear the surface. Remove all furniture, decorations, plants, pots, toys and any other items in the yard. It is necessary to work with a clear surface to ensure that the patio is well cleaned and painted homogeneously.
Repair cracks in the cement. Clean the cracks with a wire brush. Aspirate or blow dust and dirt or use a broom to make sure the cracks are clean. Fill them with a crack fill. Depending on the brand, apply the filler with a scraper or caulking gun (if necessary). To fill deeper or wider cracks, fill them up to 1/4 inch (6 mm) at a time and allow to dry between each application.
- Let the product dry according to the manufacturer’s instructions.
- Apply grout or cement-based fillers with fine sandpaper (do not sand latex-based sealers or self-leveling sealers).
Remove moss, roots and vines. Get rid of anything that has grown on the surface of the cement and spray the patio with a pressure washer if you have one. If you do not have a pressure washer, remove everything you can manually, sweep the yard and water it with a hose to remove excess clumps of grass, dust and debris.
- Ask a neighbor to lend you a high-pressure cleaner or rent one at a tool rental company or a cleaning equipment store if you do not have one of these tools. The pressure washer will be very useful to clean and rinse the cement patio before painting it.
Clean the cement surface. Cement absorbs and traps dirt and grease. To ensure that it is clean and has a fresh surface for the paint to adhere, rub the cement with a product that extracts substances, such as trisodium phosphate, muriatic acid or phosphoric acid. These products also remove old paint, which must be removed before repainting.
- Rinse the cement so that the surface is moist.
- Apply a cleaning solution (acid, trisodium phosphate or other cleaner) according to the manufacturer’s instructions.
- Rub the cement with a stiff brush.
- If you use muriatic or phosphoric acid, this process is called pickling and will ensure that the cement has a texture similar to sandpaper so that the paint adheres better. You must perform the pickling before painting new or bare cement.
Rinse the surface. It is best to use a high-pressure cleaner, as this will remove excess debris, old paint and efflorescence, a deposit of whitish salt that forms on surfaces such as cement and stucco. If there are still traces of paint on the cement, rub them with a wire brush and continue using the cleaner until the paint completely disappears.
- If you used an acid solution to remove cement, neutralize the pH of the surface by sprinkling bicarbonate on top before rinsing it.
- Especially after pickling, be sure to rinse the cement with water until no more calcareous dust comes out of the surface when you touch it with your fingers.
- Prepare to paint
Choose the painting. Since you are going to paint cement in an exterior area, any paint will not do. It is likely that common exterior paint will crack on a cement surface and peel shortly after application. There are several types of paint that will work for your cement patio and these include:
- Cement paints containing sealants or waterproofing qualities which are made to withstand water, salt, oil and grease. These are a good choice because they are specially designed for outdoor cement and to resist various substances and elements.
- Latex paints, water-based or oil-based for exteriors that are designed for floors, patios or porches. They are also a good option, since they are created for outdoor use and are specific to withstand pedestrian traffic.
- Masonry paints containing binders and additional epoxy resin. Although they can adhere well to cement, they will not necessarily protect the concrete from adverse weather conditions.
Choose a color. To help you decide what color to paint the patio, consider the color of the exterior of your home and the color of the patio furniture. Take samples of color with the paint shop so you can compare the existing decoration with your painting options. Do not be afraid to ask a painting specialist for advice.
Think about using a primer. A primer for cement will allow you to work with a homogeneous and pleasant surface, instead of the irregular and porous surface of the cement without priming. It will also reduce the number of layers needed to adequately cover the surface.
- If you are going to use one, choose an exterior primer and make sure it is designed for cement. These primers are often called concrete primers, masonry or binders.
Determine the amount of paint you need. Once you have chosen the type of paint you are going to use, it is necessary to perform some basic calculations to determine the amount of paint cans you need to cover the surface of the patio. Check the paint can or manufacturer’s website for how much coverage a can provides and compare it to the surface in square meters of the concrete area.
- To determine the area in square meters, multiply the length by the width of the area in which you are going to work. Do not worry if the patio is not perfectly square or rectangular: you only need a basic idea of the area you are going to cover.
- Do not forget to take into account if you plan to apply several layers. The primer will reduce the need to apply more than one or two coats of paint.
Gather your tools and equipment. Before you start, gather all the tools you need to paint. The most suitable tools for this work are: a masonry brush, a high capacity roller or a texturizing roller. The equipment you will need may include:
- A primer (optional) and paint
- A roller and a roller brush to paint
- A tray for painting
- Extensions for rollers and brushes
- Painter’s tape
- Thick and thin brushes
Protect surfaces. Tape the surfaces near the cement patio, such as the edges of the platform, exterior walls, doors or windows, and other areas that you do not want to paint accidentally.
Choose the right day. The ideal is to start painting on a dry day when it has not rained 24 hours before and rain is not expected in the long-term weather forecast. The best temperature to paint outdoors is 50 ° F (10˚C).
- Paint your cement patio
Apply the primer. Make sure the patio is completely dry before you start painting or applying the primer. Pour the primer into a paint tray. Take one of the finest brushes and wet it in the primer a few times. Clean the excess inside the paint tray and verify that the brush has a homogeneous layer of paint.
Start by applying the primer with the brush around the edges or places where the patio comes in contact with other structures or parts of the house.
Use a thicker roller or brush and an extender to apply the primer to the rest of the area.
Let the primer dry. Although it should dry more or less in two hours, wait at least 8 hours before starting to paint. However, do not let more than 30 days pass.
- If you reuse your brushes, rollers and trays, make sure to clean them thoroughly and allow them to dry before reusing them.
Pour the paint on the tray. The tray will allow you to easily cover the brushes or rollers evenly, therefore, it will be easier to apply even coats of paint to the area.
Paint around the edges of the patio. Use a small brush to apply a coat of paint around the edges, joints or other very difficult areas that the larger roller or brush won’t be able to do. Make sure to use a small brush to apply paint anywhere in the areas adjacent to the patio where you placed adhesive tape to ensure that no paint falls on the walls, platforms or windows.
Apply the first coat of paint. Choose a starting point, such as an interior corner that faces the house and progresses from there. Do not paint in a corner or center where you cannot go back out without stepping on fresh paint. Use even passes with the roller or brush to apply a thin and homogeneous layer of paint.
- Connect the roller or brush to an extender so you can continue standing while you paint. In this way, you will avoid injuring your back, knees and wrists.
- If you use a brush instead of a roller, make sure it is large enough to cover a large area, so that the paint does not dry before finishing a section.
Let the first layer dry. Cement and exterior paints may take more than six hours to dry before they are ready for additional layers. Therefore, be sure to check the manufacturer’s recommendations.
- You should always let the most recent layer dry before deciding if you need to apply another one.
- Depending on if you used a primer, you may need one to three coats of paint.
Apply the necessary layers. Follow the same steps as indicated above. Use a small brush around the delicate or difficult edges and a large brush or roller to complete the layer. Apply a sufficient amount of layers to achieve the intensity of color you want for your patio.
Let the paint dry and cure. Although you may be able to walk on it 24 hours later, you should wait about 7 days before placing the furniture back.
If you are going to paint a newly installed cement patio, verify that the cement has hardened before cleaning and painting it. Although some suggest you should wait 30 days, others recommend that you make sure that the cement is exposed at least 90 days before painting it.