When it comes to finishing walls, drywall compound, also known as joint compound or mud, is commonly used to create smooth and seamless surfaces. However, the question arises whether this compound can be applied on cement board, which is often used as a substrate for tile installations and in areas prone to moisture. In this article, we will explore the topic in detail to understand whether applying drywall compound on cement board is a suitable practice.
Understanding Cement Board:
Cement board is a durable building material made from a combination of cement and reinforcing fibers. It is renowned for its ability to withstand moisture and is commonly used in areas like bathrooms, kitchens, and laundry rooms, where high humidity or water exposure is expected. Cement board provides a sturdy and stable base for various applications, including tile installation, as it does not swell or deteriorate when exposed to moisture.
Properties of Drywall Compound:
Drywall compound is a gypsum-based material that is primarily used to fill gaps, cover screws or nails, and create a smooth surface on drywall panels. It typically consists of a powder that needs to be mixed with water to form a spreadable paste. After application, the compound dries, allowing for sanding and finishing to achieve a flawless wall surface.
Applying Drywall Compound on Cement Board:
1. Compatibility:
Drywall compound and cement board are compatible materials, meaning that they can be combined. Cement board provides a stable and secure base for drywall compound, allowing it to adhere well and form a smooth surface. The compound can be applied directly over cement board, regardless of the application area, such as in showers or other high-moisture environments.
2. Preparing the Surface:
Before applying drywall compound on cement board, ensure that the surface is clean and free from dirt, dust, or any contaminants that could affect the adhesion. The surface should also be dry, as moisture can hinder the compound’s ability to adhere properly. Utilize a brush or vacuum to remove any loose particles and wipe the surface with a damp cloth. If necessary, repair any damaged areas of the cement board before proceeding.
3. Applying Drywall Compound:
To apply drywall compound on cement board, mix the compound according to the manufacturer’s instructions. Use a trowel or putty knife to scoop out the mixed compound and spread it evenly over the cement board surface. Apply a thin layer of compound at first, concentrating on filling gaps or covering screws or nails. After the initial application, a second or even third layer may be required for a smooth and seamless finish. Allow each layer to dry before applying subsequent layers.
4. Sanding and Finishing:
Once the drywall compound has dried thoroughly, sand the surface using sandpaper or a sanding block. This step is crucial to achieve a smooth and even finish. Start with a coarse-grit sandpaper, gradually moving to finer grits until the surface is free from imperfections. After sanding, wipe away any dust particles and apply a primer before proceeding with the desired finishing, such as paint or wallpaper.
Applying drywall compound on cement board is indeed possible and a suitable practice. Cement board provides a stable and durable base for the compound, ensuring proper adhesion and a smooth finish. Whether it is for filling gaps, covering screws, or creating a seamless wall surface, drywall compound can be used over cement board in various applications, including those exposed to moisture. Follow the proper preparation and application techniques, and you can achieve a professional-level finish on your cement board walls.