Painting cinder blocks is an easy way to brighten up any space. Cinder blocks are commonly used for basements, garages, and outdoor projects.
This guide will teach you how to properly paint cinder blocks. You’ll learn the best paints and primers to use.
You’ll also get step-by-step instructions for prepping and painting the blocks. With a fresh coat of paint, those boring cinder block walls will look brand new!
Do You Have to Prime Cinder Block Before Painting?
If you’re planning on giving those cinder block walls a fresh coat of paint, there’s one crucial step you don’t want to skip – priming.
While primer may be optional for some other surfaces, it’s an absolute must when painting cinder blocks.
You see, cinder blocks are made of concrete which has a very porous surface. If you apply paint directly without priming first, the paint will soak right into those pores and pinholes in the concrete.
This can lead to uneven color, peeling, and a generally unsatisfactory finished look.
The solution is to use a high-quality masonry primer made specifically for concrete and cinder block surfaces.
This primer creates a nice uniform base that seals the porous surface, giving the topcoat of paint a solid bond to adhere to.
Don’t make the mistake of using a primer made for drywall or wood – it won’t do the trick on cinder blocks.
Once that concrete bonding primer is applied and dried, you’re ready to roll or brush on your choice of acrylic latex paint in the color you desire.
For interior cinder block walls, a standard interior latex paint will do just fine. If painting exterior surfaces like a cinder block fence or shed, be sure to use an exterior grade 100% acrylic paint made for outdoor conditions.
For cinder blocks in moisture-prone areas like basements, consider an elastomeric masonry paint. This specialty paint has flexibility to stretch and bend without cracking as the moisture causes the concrete to expand and contract slightly.
How To Paint a Cinder Block Wall
Painting cinder block walls can really transform a space, covering up that drab concrete gray with a fresh coat of your chosen color.
But it’s important to do it right for long-lasting results. Here are the steps to properly paint a cinder block wall like a pro:
1. Preparation is Key
Before you can even think about applying paint, the cinder block surface needs to be cleaned and prepped. Start by using a paint stripper to remove any old, failing paint that is already on the blocks.
A natural soy-based stripper works great and is environmentally friendly.
Next, you’ll need to do a thorough cleaning. For interior walls, mix up a solution of trisodium phosphate (TSP) and warm water.
Scrub this into the blocks using a sturdy nylon brush to remove any grime, grease, dirt or efflorescence (that powdery white deposit).
For exterior walls, a pressure washer is your best bet to blast away debris and contaminants. Let the wall dry completely for 24-48 hours after cleaning.
Now you’re ready to patch up any cracks or holes in the cinder blocks with polyurethane concrete caulk. This will ensure a smooth, seamless surface for painting.
2. The Priming Step
You can buy regular paint in your desired color, but first you need to apply a high-quality masonry primer.
This is an essential step that should never be skipped when painting cinder blocks.
The primer creates a stable surface for the topcoat and seals the porous concrete, so the paint doesn’t just soak in.
Use a latex acrylic concrete and masonry bonding primer, applied liberally with a thick nap roller.
You may need to do two primer coats to get nice even coverage that fills all the little pores and holes in the blocks. Let the primer fully dry for at least 4 hours before painting.
3. Time for the Topcoat
Now you’re primed and ready for the fun part – adding some color! Use an acrylic latex paint in your chosen color, ideally exterior grade for the best durability and sheen.
If you’ll be painting basement walls or other damp areas, opt for a flexible elastomeric masonry paint instead.
Apply at least two generous coats of the topcoat paint using a 1/2″ nap roller and a good paintbrush to cut in edges and seams.
For damp areas, you’ll want to do three full coats to get the recommended 10-15 mil thickness. Let each coat dry completely before reapplying, which usually takes around 12 hours.
What Kind of Paint Do You Use on Cinder Blocks?
If you’re looking to give those drab cinder block walls, foundations or outdoor features a fresh coat of color, choosing the right type of paint is crucial.
Cinder blocks are highly porous concrete surfaces that require specialized paints to ensure proper adhesion and durability.
Here’s a rundown of the best paint options for cinder blocks:
Acrylic Latex Paint
For most cinder block painting projects, acrylic latex paint is an excellent choice. This water-based paint contains acrylic resins that provide great flexibility and adhesion to the porous concrete surface.
Acrylic latex dries quickly to a smooth finish and is known for its durability.
Look for an acrylic latex paint specifically formulated for masonry and concrete surfaces. For interior cinder block walls, a standard acrylic latex will work well.
For exterior cinder blocks exposed to the elements, opt for an exterior grade 100% acrylic paint designed for better weather resistance.
Elastomeric Paint
If you’ll be painting cinder blocks in damp, moist environments like basements, elastomeric paint is worth the investment. This masonry coating contains an even higher concentration of acrylic resins compared to regular latex paint.
The increased elasticity allows the paint to stretch and expand with the concrete as it gets wet, bridging any hairline cracks that form.
Elastomeric coatings are also highly waterproof yet breathable, making them ideal for interior or exterior cinder blocks prone to moisture exposure.
Milk Paint
For those seeking a more natural, eco-friendly paint option, milk paint is an alternative to consider for cinder blocks. As the name implies, this very old formula contains few additives beyond milk protein, lime and natural pigments.
While non-toxic and versatile, milk paint does require very good surface preparation and often multiple coats for full coverage and durability on porous cinder block surfaces. The color selection is also more limited compared to conventional paints. However, milk paint can provide a beautiful, unique look for the right application.
Other Options
When painting exterior cinder block surfaces, concrete stains are another possibility to explore. These penetrating stains come in water-based and acid-based formulas, with acid stains providing longer-lasting, permanent coloring.
Regular latex paints can technically be used on cinder blocks, but they lack the flexibility, adhesion and moisture resistance of the dedicated masonry coatings mentioned above.
No matter which type of paint you choose for your cinder block project, proper surface preparation and priming are absolutely essential. Use a concrete and masonry bonding primer before applying your topcoats.
Should I Paint My Cinder Block Foundation?
If your home’s foundation walls are made of exposed cinder blocks, you may be considering giving them a fresh coat of paint.
Painting cinder block foundations is a popular choice for both aesthetic and protective reasons. Here are some key factors to help you decide if painting is the right move:
1. Improved Curb Appeal
Let’s start with the obvious – those bare grey cinder blocks aren’t doing your home’s exterior any favors in the looks department. Applying a new paint color instantly elevates your foundation’s appearance from drab to fab. Coordinate with your home’s siding hues or go bold with a crisp white or other accent shade.
2. Protect Against Water Damage
One of the biggest benefits of painting cinder block foundations is the protective barrier it creates against water penetration. The porous concrete is susceptible to moisture intrusion, which can lead to cracking, efflorescence, and interior water issues over time.
A high-quality masonry paint like elastomerics or acrylics forms a waterproof yet breathable coating that prevents water from seeping in while still allowing the blocks to expel moisture vapor. This weatherproofing prolongs your foundation’s lifespan.
3. UV Protection
Along with water, the other major threat to cinder block foundations is UV radiation from the sun. Prolonged UV exposure can cause the concrete to become dry and brittle over many years.
Painting acts as a UV-blocking shield to prevent this deterioration. The paint coating reflects the sun’s rays off the surface before they can penetrate into the blocks themselves.
4. Dealing with Existing Coatings
If your foundation has an existing coating like tar or parging, you’ll need to take extra preparation steps before painting. Tar requires full removal through acid washing and scraping – a laborious process.
Parging can be painted over, but there is a risk of trapping moisture behind the new waterproof paint layer. It’s best to wait for an extended dry period before painting over parging to avoid this moisture buildup.
Overall, painting your cinder block foundation with the proper masonry coatings provides great aesthetic and protective benefits. The water-resistant, UV-blocking properties help maintain your foundation’s structural integrity for years to come.
How to Remove Paint from Cinder Block?
Whether you’re dealing with graffiti, overspray, or just old chipping paint, removing paint from cinder block surfaces requires some extra effort compared to drywall or wood.
The porous concrete blocks can really grip onto paint, making chemical strippers a better approach than sanding or power washing alone.
Here are the steps for safely and successfully stripping paint off cinder blocks:
1. Prep the Area
Start by covering the floor beneath the painted cinder blocks with a plastic drop cloth or disposable tarp. Any nearby plants, landscaping or surfaces you don’t want exposed to stripper should also be covered. Wear proper safety gear including goggles, gloves and protective clothing.
2. Apply a Chemical Paint Stripper
Using a masonry-grade chemical paint stripper is usually the most effective method for cinder blocks. Apply a thick coat with a stiff brush, working it into all mortar joints and crevices.
For best results, apply a peel-away membrane over the stripper – this helps it stay wet longer to better dissolve multiple layers.
An alternative option to a chemical striper is sanding the area.
How to Sand Concrete: A Detailed Step-by-step Guide
3. Let the Stripper Work Its Magic
Now it’s a waiting game to allow the chemicals time to penetrate and undercut the paint. This can take anywhere from 1-6 hours or more depending on the product used. If not using a membrane, you’ll see the paint crack, bubble and lift. With a membrane, check underneath periodically until the paint liquefies.
4. Scrape and Scrub
Once the paint is lifted and softened by the stripper, use a putty knife or scraper to remove as much as possible. Get in mortar joints and stubborn spots with a stiff wire brush. With membrane products, you can often peel the entire membrane off while it’s still wet, taking most of the dissolved paint along with it.
5. Reapply Stripper if Needed
For any areas where paint remains stuck on, simply reapply a second coat of stripper and let it work for another 1-2 hours before scraping again. The porous nature of cinder blocks often requires multiple applications.
6. Power Wash Away Residue
Once as much paint as possible is manually removed, use a pressure washer set between 1500-2400 psi to blast away any remaining stripper and paint particles from the blocks. A 25–40-degree nozzle tip works best at a minimum distance of 6 inches.
7. Neutralize the Surface
Finally, you’ll want to rinse or apply a neutralizing solution recommended by the stripper manufacturer. This ensures no harsh chemicals are left behind on the now-stripped cinder blocks.
8. For Graffiti or Overspray
If dealing with unwanted spray paint or graffiti rather than multiple layers, you may be able to avoid heavy-duty strippers. Just mix up a trisodium phosphate (TSP) solution and scrub the affected areas using a stiff brush. Once the paint is off the blocks, rinse it thoroughly.
Conclusion
You have learned how to paint cinder blocks the right way. First, you prep the surface by cleaning it well. Then, you apply a concrete primer. After that dries, you paint with a masonry paint made for cinder blocks.
It’s an easy project if you follow the steps. Don’t leave those dull gray blocks as-is any longer. Paint them a nice color to brighten up the space. It will look so much better!