Multipurpose cement board has become a staple in modern construction and home improvement projects. It is a highly durable, water-resistant building material used as a base for tiling, flooring, and even as an exterior sheathing option. Cement boards are composed of cement and reinforcing fibers, making them ideal for areas that require strength and moisture resistance, such as bathrooms, kitchens, and basements.
In this article, we’ll explore how to effectively use multipurpose cement board in a variety of applications, from preparation to installation.
1. What Is Multipurpose Cement Board?
Multipurpose cement board is a strong, versatile material that provides a stable, moisture-resistant surface for various types of finishes, including tile, stone, and paint. Commonly used in areas prone to moisture and heavy use, it serves as a robust underlayment for countertops, walls, floors, and exterior finishes. It is also fire-resistant, making it a great choice for projects that require both safety and durability.
2. Where to Use Multipurpose Cement Board
Due to its moisture resistance and strength, multipurpose cement board is used in the following areas:
Bathrooms: Cement board is an excellent base for tile installation in showers, tub surrounds, and bathroom floors, where moisture can compromise other materials.
Kitchens: It provides a sturdy surface for tiling kitchen backsplashes and countertops, which are often exposed to water, heat, and heavy use.
Basements: In basements that may be prone to dampness or flooding, cement board can help protect walls and floors from moisture damage.
Fireplaces: Cement board is often used around fireplaces as a non-combustible surface that can be tiled or finished with decorative stone.
Exterior Sheathing: Some cement boards are designed for exterior use, providing a durable surface that can withstand weather conditions.
3. Tools and Materials Needed for Installation
Before starting any project with multipurpose cement board, gather the necessary tools and materials:
Cement board sheets (typically available in 3×5 or 4×8-foot sizes)
Measuring tape
Straight edge and pencil (for cutting and marking)
Utility knife or cement board scoring tool
Screws specifically for cement board (galvanized or coated to prevent rusting)
Drill or screw gun
Fiberglass mesh tape for sealing seams
Thin-set mortar or tile adhesive
Trowel (for applying mortar)
Level (to ensure straight installation)
4. Step-by-Step Guide for Installation
4.1 Preparing the Surface
Before installing the cement board, ensure the surface is clean, dry, and structurally sound. For floor installations, make sure the subfloor is level and capable of supporting the cement board’s weight. If you’re using cement board on walls, check that the studs are spaced properly and securely fastened.
4.2 Measuring and Cutting the Cement Board
Start by measuring the area where the cement board will be installed. Mark the cement board with a pencil and straight edge to ensure precise cuts. To cut the board, score the surface with a utility knife or a cement board scoring tool. Then, snap the board along the scored line to break it cleanly.
For more intricate cuts, such as around fixtures or corners, you may need a jigsaw with a carbide blade. Be sure to wear appropriate safety gear, including goggles and a mask, as cutting cement board produces fine dust.
4.3 Positioning the Cement Board
Once your cement board is cut to size, place it onto the prepared surface. On floors, leave a small gap (about 1/8 inch) between the cement board and walls to allow for expansion. Align the edges of the board carefully and ensure it’s level before securing it in place.
4.4 Securing the Cement Board
Use cement board screws to attach the board to the subfloor or wall studs. Place screws about 8 inches apart along the edges and 12 inches apart in the center of the board. Drive the screws in until they’re flush with the surface, but be careful not to over-tighten, as this could damage the board.
For exterior or high-moisture areas, be sure to use screws that are specifically designed for outdoor use and moisture resistance. These screws are typically galvanized or coated to prevent rusting over time.
4.5 Sealing the Seams
After securing the boards, seal the seams between them using fiberglass mesh tape. Apply the tape over the joints and cover it with a thin layer of thin-set mortar or tile adhesive. This step helps create a smooth, even surface and prevents cracks from forming along the seams when tiles or other finishes are applied.
4.6 Tiling or Finishing the Surface
Once the seams are sealed, the cement board is ready for the final finish. If you’re installing tile, apply a layer of thin-set mortar using a notched trowel, and press the tiles into place. For other finishes, such as paint or stone veneer, follow the manufacturer’s instructions for best results. Cement board provides a stable surface that won’t warp or degrade over time, ensuring a long-lasting finish.
5. Benefits of Using Multipurpose Cement Board
Moisture Resistance: Cement board is resistant to water and mold, making it ideal for wet environments like bathrooms and kitchens.
Durability: It’s a tough, impact-resistant material that can handle heavy loads and won’t rot or warp over time.
Fire Resistance: Cement board is non-combustible, which makes it a safe choice for areas exposed to heat, such as around fireplaces.
Versatility: It can be used in a variety of applications, including as a base for tiles, stone, or even stucco in exterior walls.