How to Paint Concrete?

Contrary to popular belief, concrete surfaces (both interior and exterior) do not have to remain a flat and dull shade of gray. If willing to invest the time and effort, concrete can be improved to look more interesting and beautiful by applying a few coats of paint. Painting concrete is a fairly simple and inexpensive task that most homeowners can complete. To successfully paint concrete surfaces, you must make sure to properly clean and prep the area, apply the appropriate concrete paint and always allow adequate time for the paint to cure.

The two main areas that we will focus on are Preparing the concrete for painting and finally, the actual painting of the concrete.

 

Preparing the Concrete

Clean the Concrete

It is important to ensure that you clean the concrete surface by following these steps:

  1. Sweep away any surface debris such as leaves and dirt.
  2. Remove any existing paint or stuck on debris using a power washer
  3. Stubborn grime can be removed using a scraper and wire brush.
  4. Remove any branches, moss or other plant life covering the concrete.
  5. A final cleaning of the surface with soap and warm water to make sure that any dirt, old paint, etc. is removed

If after final cleaning, you still see some stains, you need not worry as long as they are set in the concrete and not some other material or debris sticking on the surface.  You want the concrete surface to be as clean and bare as possible for the best paint results. 

 

Remove Oil & Grease

With a number of concrete surfaces, we experience areas where oil or grease have been spilled and marked up the concrete.  To deal with these areas, we suggest using tri-sodium phosphate (TSP) as this should remove the oil/grease while ensuring the paint doesn’t discolour later. TSP is available at most major home improvement stores. Follow the instructions by mixing with water at the stated ratio on the packaging.  Apply to the stains and work in to the area followed by rinsing the cleaner off when complete. Allow the concrete surface to dry completely before proceeding with the next steps.

 

Concrete Patching

When working with concrete, it is common to find areas with cracks, gouges or uneven surfaces.  It is important to fix these defects and this can be done through concrete patching the areas in question.  You will want the concrete to be as smooth as possible and then apply to the issue areas.  The reason that it is important to complete this patching is that any breaks and cracks in the concrete are places where moisture could potentially get under the paint causing it to peel or flake off the surface later on. Make sure to read the manufacturer’s instructions to confirm proper drying time for the patch.

 

Concrete Sealant

Typically meant for indoor, sealant is used to prevent moisture from coming through the concrete. Sealant can be expensive; however, it is the best way to ensure that you don’t ruin your paint job soon after applying it. Concrete is very porous, which means that moisture trapped within the concrete could rise and ruin the paint. Again, follow the manufacturer’s instructions for the proper preparation and application of the product.

This is not as necessary if you are painting outdoor concrete.

 

Concrete Painting

Watch the Weather

When looking to paint your outdoor concrete, it is important that you refer to the weather forecast to ensure you have 2-3 dry days in a row.  You’ll need to give the paint ample time to dry in between each coat. Make sure and refer to the manufacturer’s instructions as different paints will have their own, specific drying times. In some cases, paint can take up to 24 hours to dry completely which is why it’s important to give yourself ample time to complete the painting process.

 

Time to Prime

The primer is an important step as it is what allows the paint to stick to the concrete.  Apply 1 layer of concrete paint primer with a paint roller. Again, follow the manufacturer’s instructions to confirm the necessary application and drying time.

If you are painting over an old color or are working outdoors, 2 coats of primer will likely provide the best results. Make sure that the first coat is completely dry before applying the second coat.

 

The Right Paint for the Job

When working with concrete, your best bet is to use masonry or epoxy paint.  This type of paint is good for the conditions here in Edmonton because it is formulated to contract and expand as concrete changes temperature. You will soon see that this paint is much thicker than regular paint and with this, you will need to ensure that you have a high-capacity roller or brush to apply to your concrete.

 

First Coat

Once the surface is fully cleaned, primer is applied and the correct paint has been chosen, it is time to start painting. Apply a thin, even coat of paint using a paint roller. We recommend starting in one of the corners and working slowly and evenly across the entire surface. Being a thicker pain, you won’t need as much paint as you may think in each layer.  Depending on the location and surface, you’ll be adding 1 or 2 more layers once the first is done drying, so there is no need to apply a heavy layer on the first application.

 

Second Coat

It is typically recommended to let the first coat of paint dry over night so you can return the next day to apply a second coat.  Again, allow the second coat to dry overnight and then look to apply a third and final coat of paint.  This third coat should be a thin layer to finish up the job by providing an even coating and deeper colour.

 

Final Step

Once the final coating of paint has been applied, you should allow to dry for at least 24 hours and then apply several coats of masonry sealer, using a clean roller.  Make sure to allow each coat to dry prior to adding additional coats. Wait 1-2 days before stepping on or placing anything on the concrete.

 

Here is some additional, related info if you want to dive deeper. 

For any advice related to concrete painting in Edmonton, contact Brett at Garden Concrete Services!