A brick wall can ruin the aesthetic beauty of your home if it gets dingy and dirty. The best way to add elegance to your brick wall and brighten the room is to apply a fresh coat of paint, which can create a cleaner, more even finish.
Typically, the rough surface of a brick wall makes it a great surface for paint to adhere to. 
However, due to its porosity it can also be tricky. Because of the porosity, brick walls are likely to absorb a lot more paint – a brick wall can absorb between 20%-50% more paint than a normal surface would. Furthermore, the person who is appointed to paint a brick wall should be familiar with the process of filling gaps and cracks in the brick wall before applying paint. The task of applying the paint in the grooves between bricks requires a good level of expertise and experience, not to mention, patience. A generous amount of time should be allocated for painting any brick surface.
The Prep Work:
Surface preparation is the key to getting a good paint job, especially if you have a brick wall to paint. You can scrub the brick wall gently by using a hard nylon brush, then vacuum the surface in order to remove any loose mortar, dirt, or dust. In addition, you need to take a bucket full of warm water and mix in a couple drops of a liquid soap or a handful of mild detergent powder. It is important to wash the bricks with the soap and water mixture to remove any excess dust and dirt and allow the wall to dry completely. Generally brick takes around 12 hours to dry properly, but if you find the bricks are cold, it probably needs to dry a little longer.
It is also important to affix painter’s tape to all the adjacent walls and trim that you don’t wish to paint. You can also cover your furniture with a canvas sheet or plastic drop cloth in order to protect them from paint drips.
Applying The Primer & Paint:
It is important to apply a good quality primer on the edges and corners of the brick wall by using a 2½ inch wide nylon polyester brush. For the rest of the brick surface, you can use a 1¼inch nap roller to apply the primer.
When it comes to painting interior brick walls, you should always use a high-quality water-based acrylic paint. Allow the paint to dry properly and then you can apply the second coat if needed.