Bricks are porous, which means they absorb paint quickly and require more than one coat. In addition, they have many nooks and crannies, which means the paint tends to pool in certain areas. These factors not only make bricks tricky to paint, but also make the paint almost impossible to remove. Once you paint bricks, it is hard to get the paint off, so make sure painting them is really what you want to do.
Clean your bricks. Scrub them with a scrubbing brush and hot, soapy water to get any soot off the bricks. If soapy water is not enough, scrub with straight white vinegar.
Repair the mortar or any holes in the bricks. Use filler and a putty knife for small cracks or holes, or caulking for bigger gaps in the mortar.
Protect the area. Use painter's tape to protect nearby walls, and cover the floor with an old sheet or plastic sheeting.
Apply primer. Use a primer that is 100 per cent acrylic. First, use the roller to apply the primer. Work from the top down. Painting brick is different from an interior wall in that you do not have to be as careful and neat with your strokes. Choose a section about 75 cm square then work the roller in all directions, covering as much of the brick and mortar as possible.
Use a paintbrush to pick up drips and runs, and to fill in the mortar. The roller will not be able to fill in the mortar completely, so use the brush to dab paint into empty spaces. Check the corners of the bricks, as this is where the most paint will pool. Once you have used the roller and brush on one section, move on to another section, and repeat.
Apply the white paint. Again, use an interior, water-based acrylic paint. Use the roller and brush just as you did when you applied the primer. Let the paint dry completely, then add another coat in the same way. You may need to add a third coat, depending on how bright you want the white colour to be.
Many experts suggest whitewashing bricks instead of trying to paint them white.
Make sure your area is well-ventilated while you are working with the paint and primer.