Cement render is a thin premixed plaster texture consisting of cement, sand and lime. It adds beauty to brick, stone or cement. Though cement render is paintable, it will eventually chip and peel unless it is pretreated with a masonry primer. Because cement render usually contains tiny bumps, it requires a certain type of paintbrush that works well with coarse surfaces. Finish your cement render, using the correct tools or you may end up with skipped areas within the bits of texture.
Wash the cement render, using a pressure washer. Don't hold the tip of the washer too close to the cement render or you may damage it. Maintain at least 4 feet between the render and sprayer tip as you wash. Let the render dry for four to six hours.
Cover areas next to the cement render, using painter's tape. Identify painter's tape by the blue colour.
Place dust sheets beneath the cement render to prevent stains.
Apply masonry primer to the cement render with a roller. Roll vertically across the render, moving left to right. Touch-up skipped portions of the render, using a nylon brush. Polyester brushes are not suited for rough textures and won't provide adequate coverage. Let the cement render dry for two hours.
Wash the brush and roller, using a water hose.
Paint the cement render as you primed it. Use two coats of acrylic latex paint, waiting two hours between each coat.
Ordinary latex primers won't bond well to cement render. If you want the finish to last, choose a primer made for nonporous masonry surfaces.