How to Prepare a Concrete Floor for Painting
Do all repairs needed before painting
Part of the preparation process is to do all minor and major repairs not only to the concrete floor but also with the adjacent walls, cabinets, and particularly with the joints and joint edges. Doing repairs after painting will only damage the coat, so to be sure, do some inspections first.
Clean dust, dirt, and other debris
The very basic way of preparing the concrete floor is to clean away dirt, dust, sand, and other debris. Dust and dirt will affect the adhesion of paint while debris can cause unevenness and bumps in the coat’s surface. There’s no special technique when it comes to cleaning dirt and dust. You can use your ordinary cleaning aids and materials including water.
Test for residues of the curing compound
According to flooring experts Regal Floor Paint, if you are planning to paint a newly poured concrete, you should wait and allow the curing chemicals to dissipate. Curing compounds are used in concrete to ensure a speedy and tough hardening. But such chemicals have a very high pH levels which prevents good paint adhesion. In general, newly poured concrete are left for about 30 days before painting. And if you are not certain, you can do a simple acid test. Using muriatic acid, pour a small amount on the concrete. When it bubbles upon contact with the concrete, it’s now good to paint. And when it doesn’t, it means that there’s still that curing compound residue.
Check and remove oil and water or moisture
Aside from dirt and debris, you should also ensure that your concrete floor is free from oil and moisture. Paint will not adhere to oil, grease, and water. Additionally, it can also contribute to early peeling of the coat. The presence of oil and moisture can easily be tested using an adhesion or duct tape. When it fails to stick on the concrete, there can be dirt, oil, or moisture issue.
Ensure a lightly porous concrete surface
Concrete floors are usually constructed and finished with a smooth surface. The problem with a very smooth floor surface is that it translates to a weaker bond with the primer and paint itself. A certain extent of roughness or porosity is essential to create better bond with the floor paint. If your concrete floor is too smooth and polished, there are several ways to create that needed texture. Examples include acid wash or etching and grinding.
For removing old paint
For old concrete floors or when you are simply changing the old paint, preparation involves the clearance of old coatings and other types of finishing. This can be done through acid etching, grinding, chisel scraping, scarifying, scabbling, and shot blasting.
