How to prepare cement walls for painting

Paint a wall of cement, concrete or more accurately, you can transform the outside of a building, room or even a basement in an element of design appeal. Preparing the paint wall is important for optimum results. Rush at work can cause the paint will not stick to the concrete, which entails having to do a task that takes time.


  1. Scrape old paint if walls were painted beforehand. Be careful if the paint looks old, as it may contain lead and is considered a health hazard.
  2. Clean the walls thoroughly to remove all dust, dirt, old paint and oil. Typically trisodium phosphate (TSP) and a hard bristle brush are used to rub the concrete walls. You can use a pressure washer to clean exterior walls.
  3. Patch loose areas or holes with a compound formulated for concrete or masonry patches. Follow the compound patch specific instructions.
  4. Use etching acid on concrete walls that have never been painted, or if previously applied paint did not adhere well. The use of etching acid creates a slightly rough texture like sandpaper for the paint to adhere well.
  5. Seal and prepare concrete. The concrete seal stops moisture and the primer allows the paint to adhere. Apply the sealant with a roller and let it dry completely. Apply the primer with a roller. Once the primer is dry, the wall is ready and ready to paint.

Tips & Warnings

  1. TSP is used as a cleaning agent, degreaser. It is an ionic salt and has an alkaline ph. Follow the manufacturer’s instructions carefully when using TSP and make sure you wear gloves and eye protection.
  2. Concrete patching products are typically found in the masonry department of home improvement stores.
  3. Professionals use muriatic acid in water to burn concrete. You should be especially careful if you take this step yourself instead of hiring a professional. According to True Value, “Muriatic acid can cause severe chemical burns as a result of contact with the skin or eyes, as well as irritation of the nose and throat by inhalation of vapors.” Many companies now offer safer alternatives than muriatic acid. Check with your home improvement store to learn about other options for concrete engraving. If you use muriatic acid, wear safety goggles, rubber gloves and appropriate clothing. Carefully read and follow the product’s instructions.
  • Muriatic acid, trisodium phosphate and paint should be handled with extreme care. You should ensure adequate air circulation and protect your eyes and skin when working with these products.