While cement backer boards are designed to be covered with tile, you may be wondering if plastering is a viable option. The short answer is no, plastering is not recommended directly over a cement backer board. Plaster is generally not compatible with cementitious surfaces and may not adhere properly, leading to issues such as cracking, peeling, or detachment.
Reasons why plastering is not recommended on cement backer boards:
- Different materials: Plaster is typically designed to adhere to surfaces such as drywall or lath and plaster. Cement backer boards are made of a different composition and have a rougher surface, making it difficult for plaster to bond properly.
- Moisture resistance: Cement backer boards are designed to be moisture-resistant, whereas plaster is not. Plaster is more prone to damage or deterioration when exposed to moisture, which is commonly found in areas where cement backer boards are used, such as bathrooms or kitchens.
- Flexibility: Cement backer boards are specifically engineered to be rigid and stable, providing a solid foundation for tile installation. Plaster, on the other hand, is more flexible and prone to cracking or separating when applied on a rigid surface like cement backer boards.
Alternatives to plastering over a cement backer board:
If you are looking for a smooth and finished appearance over a cement backer board, there are alternative options you can consider:
- Skim coating: Instead of plastering directly on the cement backer board, you can apply a skim coat of joint compound or a specialized skim coat product. Skim coating involves applying a thin layer of material over the backer board to create a smooth surface. This method is commonly used to prepare walls before painting but can also provide a suitable surface for alternative wall finishes.
- Tile installation: Cement backer boards are primarily used as a substrate for tile installation. By adhering to the manufacturer’s recommendations, you can achieve a beautiful and durable tile installation over a cement backer board. This is the most common and recommended method for utilizing cement backer boards.Plastering directly over a cement backer board is not recommended due to the differences in materials, moisture resistance, and flexibility. Cement backer boards are intended to be covered with tile, which provides a suitable surface for these types of installations. If you are looking for a smooth finish, alternatives like skim coating or tile installation should be considered. By following the manufacturer’s instructions and utilizing appropriate techniques, you can achieve a successful and long-lasting tiling project using a cement backer board.