The best thing about exterior concrete block walls is their exceptional long-term durability. A decent concrete block wall will effectively protect the home for decades to come. However, concrete painting is more difficult than painting most surfaces: it breathes, it transports moisture, and it sucks paint. While you can paint drywall in a day or two, it will take you a week or more to finish concrete painting. So, it’s always best to hire a professional exterior painter than doing it yourself.
Here are 5 steps that help you paint concrete walls:
Clean the Wall
As is the case with all outdoor and indoor painting jobs, the whole thing begins by making the surface completely clean. If there is any residual dirt or grime left over, the end result will be detrimental. The best way to clean a concrete block wall is to tackle it at around 2000 psi max, with a pressure washer. If this is not an option, the combination of warm water, a sponge, a scrubbing brush, and a good bit of elbow grease will make the job nicely done. If an existing coat of paint is already in place, the cleaning may require you to be somewhat more aggressive.
Repair the Mortar
After giving the whole thing plenty of time to dry, this is the perfect time to make repairs to the mortar where necessary. A valuable tip from us – always uses a premixed acrylic mortar patch to save time and energy to mix and dry the mortar yourself. And use the product as instructed by the manufacturer, again giving things plenty of time to dry out before moving on to the next level.
Prime the Surface of the Wall
Regardless of whether or not there is already a paint coat on the surface, you will need to cover it with a quality acrylic block fill primer. You will also have to apply the acrylic block fill-primer to the mortar. The rougher and more uneven the surface, the more acrylic block fill primer you'll need to prepare. As a rule of thumb, for every 200 sq / ft of smooth concrete block surface, you will need 1 gallon of acrylic block fill primer somewhere in the region.
Caulk and Seal
When you come across any cracks or gaps that are likely to allow water through the stonework, now is probably the time to fix them. It's always worth going over your stone surfaces as intensively as you can, to see if and where they could do with being repaired. Elastomeric caulk is just about the safest caulk you can use to fix cracks and gaps in your stonework, applying them according to the directions of the manufacturer. If there is any serious damage to the stonework, it may be necessary to call a professional.
Painting the Concrete Block
Last but not least, the time has come to get busy with the painting itself. Elastomeric paint is once again the best form of paint to be used for exterior concrete walls, but a premium 100 percent acrylic paint will also do the job nicely. As far as the application is concerned, it is best to use an airless sprayer to add a thin and even coat of paint, working with the same speed and focusing on one small section at a time. A minimum of two coats should be applied, but more may be required depending on the type of paint you use and it’s color. Make sure you give plenty of time for each coating to dry and apply the paint slowly and steadily to prevent drips and a generally uneven finish.