Tools and Materials
Understanding What You Need
- Type of cleaner: Use a concrete cleaner to get rid of any dirt, grime, stains or deposits.
- Type of primer: Concrete blocks are highly porous. Applying a regular primer will be ineffective as the pores will easily absorb the primer. Select a bonding concrete primer.
- Type of paint roller: Using a nap roller for concrete blocks better fills in the block's uneven surface for an even paint coverage.
- Type of paint: For painting concrete blocks, you will need to use a durable paint option like acrylic-latex paint in your color of choice. If your concrete blocks will be used outdoors, consider selecting an elastomeric paint that is weatherproof.
To figure out how much paint and primer you will need for painting concrete blocks, measure the length and breadth of the concrete block to give you the square footage. Most paint cans mention how much area it will cover. Typically, three coats are required. Be sure to factor this into your calculations. Nevertheless, it is always better to have an extra 1⁄2 gallon of paint.
- Safety First : Work in an area with good ventilation. Consider painting your concrete blocks with a low VOC paint and wear a respirator while you work. Wear gloves and have a stable surface to work to prevent the concrete block from tipping over and causing injuries.
Prep Work and Cleaning
- If your concrete blocks already have paint over them, you will need to remove it. Use a paint stripper over the concrete surface and scrape the softened paint with a paint scraping tool.
- While some concrete cleaners require you to directly apply it over the concrete surface, some cleaners might require you to dilute it. Follow the manufacturer’s label for instructions on application.
- Alternatively, you can add a pressure washer detergent formulated for concrete to your pressure washer to clean the blocks.
- If you don’t have a pressure washer, you can also use a scrub brush along with the cleaner and a garden hose for an effective result.
To avoid damaging the concrete blocks, use a wide sprayer, with 3000 PSI and stand at least 3 to 4 feet away from the blocks as you soak them.
- To let the primer and paint adhere properly, you have to let the concrete block dry after it is wet. Allow the concrete block to dry for 48 hours before you proceed with the next steps.
If you notice any cracks on the block, you can use a concrete caulk. Apply this caulk within the cracks and allow it to cure for atleast a day. However, it is best to refer to the instructions for drying time.
Applying Primer to the Concrete Blocks
- Pour your primers into a lined paint tray and soak the rollers into it. Roll the paint roller over the textured area of the paint tray to distribute the paint evenly. Now, apply the primer on the concrete blocks with even strokes.
- Generally, you should allow the primer to dry for 4 hours but follow any instructions on your primer for drying time.
If the primer color is going to be the same as the paint, only one should be enough. If the paint is significantly different in color than the primer, apply two coats. Regardless, it is always better to apply two coats of primer to better fill in the pores and ensure better adhesion of the paint.
How to Paint Concrete Blocks
- Just like you did for the primer, use a nap roller and follow the same steps as above. Apply the paint over the concrete blocks, but make sure that you are not applying excess paint. Avoid pooling the paint to prevent drips. Too much overlapping of the paint can give an uneven look to the first coat.
- Use a nylon brush for details and corners to achieve a neat finish.
- Let the first coat of paint dry for at least 12 to 18 hours before you apply the second coat.
- To check whether the paint has dried completely or not, you can use a dry, clean cloth to touch the painted surface and ensure that there is no transfer of paint.
- Follow the same methods for an even application of the second coat of paint and this time, allow it to dry for at least 24 hours in a well-ventilated area.