Is It Possible to Spray Paint Concrete?
Yes, you can definitely spray paint concrete surfaces to change their appearance and protect them from the elements. With the right preparation techniques and paint products, you can achieve beautiful, long-lasting results. Spray painting concrete is a relatively easy DIY project that can transform dull, weathered concrete into an eye-catching accent for your home's exterior or interior.
While spray painting concrete is possible, it's important to understand that not all paints adhere well to concrete's porous, alkaline surface. Special considerations must be made regarding surface prep, primer, topcoats, and maintenance to ensure success.
Choosing the Right Concrete Paint
When selecting a concrete paint, consider the location of the surface (interior vs. exterior), the desired finish (gloss, satin, matte), and the level of durability needed. Acrylic latex paints are easier to apply and more budget-friendly but less durable than epoxy or polyurethane paints.
Acrylic Latex Paint
Water-based acrylic latex paints are commonly used for painting concrete. They provide good adhesion and allow moisture vapor to pass through the concrete surface. Acrylic paint is flexible, making it unlikely to flake or peel from minor cracks. It's relatively easy to apply with a roller, brush or sprayer.
On the downside, acrylic paint fades faster than other options when exposed to sunlight and weather. It also stains easily and requires more frequent repainting - usually every 1-3 years for exterior surfaces. Acrylic paint tends to have a matte to satin finish.
Epoxy Paint
Epoxy paint provides a highly durable and protective coating for concrete. It adheres tightly, covering hairline cracks and flaws. Epoxy paint creates a thick, plastic-like surface that stands up well to heavy foot traffic, chemicals, oil, and abrasion.
Most epoxy paints contain two components that must be thoroughly mixed before application. It cures to a hard, glossy finish that reflects light and resists yellowing from UV exposure. Properly applied epoxy paint can last 5-10 years on exterior concrete surfaces.
Epoxy paint has excellent adhesion on bare concrete but may require special primers on previously painted surfaces. The thick coating can show imperfections like trowel marks or patches. Surface prep is very important for successful results.
Polyurethane Paint
Polyurethane paint combines the toughness of epoxy with the flexibility of acrylic latex paint. It provides good UV resistance and gloss retention. Polyurethane concrete paint develops a hard yet slightly flexible film that resists cracking, blistering and peeling.
Oil-based polyurethane paints have strong fumes during application but create a smooth, glass-like finish. Water-based options have low odor and easy soap and water cleanup but take longer to cure. Like epoxy paint, polyurethane coatings require more prep work but provide long-lasting protection.
Preparing Concrete for Painting
Proper surface prep is crucial for concrete paint to adhere. Start by cleaning dirt, grease and existing paint with a degreasing concrete cleaner. Use a pressure washer to remove loose material and reveal bare concrete.
Repair cracks, fill divots, and smooth patches to create a uniform surface. Let repaired areas fully cure before painting. If the concrete is newly poured, wait at least 30 days for complete curing before painting.
Remove efflorescence (white powdery deposits) with an acidic etching solution. Rinse thoroughly and allow the concrete to dry completely before priming and painting.
For maximum paint adhesion, etch the surface with muriatic acid or other etching solutions. Wear protective gear while etching and follow all safety precautions.
Apply a masonry primer before painting for enhanced protection. Primers fill pores in concrete and create a binding layer between the paint and surface.
How to Spray Paint Concrete
Once the concrete is cleaned, repaired, etched, and primed, the actual spray painting process is relatively straightforward.
Use painter's tape to mask off any nearby surfaces you don't want painted. For large floor areas, work in sections of around 10' x 10' to maintain a wet edge and prevent lap marks.
Thin the first coat by diluting the paint with the manufacturer's recommended thinner amount. This allows the paint to seep into the concrete pores for maximum adhesion.
Apply in a steady back-and-forth motion, slightly overlapping each pass to ensure even coverage. Let the first coat dry completely per the manufacturer's specifications before adding the topcoat.
The topcoat can be applied unthinned. Use steady spray strokes and blend the new paint into the edges of the previous section to avoid lap marks. Allow proper drying time between coats.
Apply at least two topcoats for best coverage and durability. Adding multiple thin coats creates a more attractive, long-lasting finish than one thick coat.
Tips for Spray Painting Concrete
- Use long extension poles for easier maneuvering on floors, walls, and ceilings
- Keep the spray tip around 8-12 inches from the surface
- Maintain a consistent speed - about 5 seconds per linear foot
- Apply in a criss-cross pattern for even coverage of textured surfaces
- Work in a well-ventilated area and wear a respirator when spraying
Caring for Painted Concrete
Allow freshly painted concrete a full 7 days to cure before regular use. Avoid parking vehicles or placing heavy objects on painted garage floors during this time.
Reapply protective concrete sealers every 2-3 years to shield painted concrete from moisture, salt, chemicals and UV rays. This helps maintain the paint and prevent staining, blistering, peeling and fading.
Immediately wipe up spills on indoor painted concrete to prevent stains. Gently scrub with mild detergent and rinse well with clean water.
Outdoor concrete may need pressure washing every year or two to remove dirt and mildew buildup. Recoat faded or damaged areas as needed to keep the paint looking its best.
Common Questions About Spray Painting Concrete
What kind of sprayer do I need?
An airless sprayer with a .015-.019 tip is ideal for spraying concrete paint. Air-assisted airless sprayers also work well. Small concrete projects can be painted using inexpensive HVLP spray guns.
Should I use a paint and primer in one?
Primer and paint in one products save time on small DIY jobs but may not provide the same level of durability as a separate primer. For heavily trafficked or outdoor concrete, using a primer is recommended.
How long does painted concrete last?
With proper surface prep and application, painted concrete can last from 3-10 years depending on the paint type, environmental factors and usage. Epoxy paint lasts the longest on outdoor concrete surfaces.
Can I paint over existing concrete paint?
Yes, previously painted concrete can be repainted after thorough cleaning and scuff sanding to remove any gloss. Unsound paint should be removed completely before recoating.
Exterior paints are formulated to withstand weathering, sunlight, temperature changes and moisture. Interior concrete paints have more color options but are less durable.
It is possible to achieve beautiful spray painted concrete surfaces, whether inside or outside the home, with the right concrete paint products. Paying attention to proper application techniques will also help ensure your painted concrete has a like-new appearance for years to come.