In this guide to concrete floors, you’ll discover the do’s and don’ts of painting concrete floors. Can you just paint concrete floors? How do you paint over old concrete? These questions and more will be answered in this article, so when you do paint concrete floors, you can be assured the job will not only look good, but last.

How do you paint over a concrete floor?

A bare concrete floor is basically unprotected and a coat of the right paint will offer the concrete the protection it needs to last longer.

To paint a new or bare concrete floor, first you’ll want to wash the floor to remove any debris, including concrete dust, for better adhesion. Depending on how smooth you want the finish to be, you may even want to sand the floor first and then vacuum up the dust particles. The next step is to fill any cracks and holes with a specialised concrete filler or patch compound.

When the concrete has been prepared, prime the floor with a concrete floor primer and then apply a coat or two of an epoxy paint. Once the paint has completely dried, coat the paint with a sealer to add an extra layer of protection for both the paint and the concrete. The sealer will also help to protect the floor from spills and moisture damage.

The easiest and quickest way to paint a concrete floor is with a roller, although you could use a spray gun for very large surface areas. Use a brush to cut in around the edges of the floor, either before or after rolling the surface.

Can I paint over sealed concrete?

This is a good question.

The problem with painting over a concrete floor that’s already sealed, particularly if it’s been sealed with an acrylic sealer, is you won’t get a satisfactory bond of the new paint to the previously sealed surface. The reason being, is there is simply not enough adhesion for the new paint to adequately seep into and stick to a sealed surface.

Before painting a concrete floor that’s been sealed previously, it’s best to sand the floor first to roughen up the surface and give the paint something to bond to. You could take things a step further and have the sealed concrete sandblasted to scour the surface. Once the floor has been roughened up and thoroughly cleaned, apply an etching solution for increased adhesion, then you can successfully apply a coat of fresh paint.

A quality painting finish is more about the right preparation than simply applying a nice coat of paint, so take the time to properly prepare the surface first.

Can I paint over existing paint on concrete?

This point is similar to wanting to repaint a concrete floor that has previously been sealed. Even if that old surface was finished off with a coat of sealer, you’ll first want to adequately prepare the surface prior to painting it.

The preparation required will largely depend on the condition of the old paint and the concrete. For example, if there are areas of flaking paint, this paint will first need to be scraped away. You will then want to sand back the old paint for more adhesion and thoroughly clean the surface area prior to applying any fresh paint. If there are cracks or holes in the concrete, fill these with a concrete patch or filler first and allow to completely dry.

Once the surface has been properly prepared, applying the new coat of paint can then take place. It’s always wise to apply a sealer once the new paint is dry for further protection.

How do you paint over old concrete?

Old concrete, whether it has previously been painted or not, can present a few extra challenges due to its age and general wear and tear over the years. There is far more chance that an old concrete floor will have areas of crumbling concrete, along with more cracks and holes that will need to be filled.

For crumbling concrete, remove the damaged area and replace with fresh concrete. For cracks, holes and areas of minor crumbling, you can resolve the problem with polymer resins or a vinyl concrete patch. These patches are great for evening out a surface and create a secure and strong bond.

With the surface prepared and up to standard, you can now start the painting process and have that old concrete floor looking like brand new.

Do I need to prime concrete before painting?

If you’re wondering, “How do you get paint to stick to concrete?”, it all comes down to preparation, as we’ve largely covered already in this article. A very important part of that preparation is applying a primer coat once the concrete floor has received any necessary repairs and is completely clean.

A coat of the right primer not only acts as a seal and protector between the concrete and the finish coat of paint, but it also helps to bond the finish coat to the floor more effectively. Without first priming a bare concrete floor, you could end up with issues down the track that include moisture problems or the top coat of paint bubbling and lifting off from the concrete surface.

Coating the concrete floor with a primer is an essential part of the painting process.

What is the best type of concrete floor paint?

The type of paint you decide to paint your concrete floor with will depend on the results you are trying to achieve. If the floor is going to see a lot of activity, such as in an industrial premises, then the finish coat of paint will generally be different to what you might use for a more decorative finish that won’t see much wear and tear, such as for a patio, for example.

The best way to determine what paint is right for your needs is to consult industry experts and concrete paint suppliers for the best advice.

In Conclusion

Successfully painting a concrete floor is not rocket science. So long as your preparation is good and you only use high quality primers, paints and sealers, there’s no reason the finished project can’t stay looking great for many years to come.

Images courtesy Epimax