Before delving into the question of whether backer board can be used for exterior siding, it is essential to understand what exactly backer board is. Backer board, also known as cement board or cementitious backer unit (CBU), is a versatile material made from a combination of cement and reinforcing fibers. It is commonly used as a substrate for ceramic, porcelain, or stone tile installations. Backer board comes in various thicknesses, ranging from 1/4 inch to 1/2 inch, making it suitable for different applications.
Benefits of Using Backer Board for Exterior Siding
- Durability: Backer board is known for its exceptional durability, making it an excellent choice for exterior applications. It is moisture-resistant, which is vital for withstanding various weather conditions. Additionally, it is resistant to termites and other pests, ensuring the longevity and integrity of your siding.
- Fire Resistance: Backer board has excellent fire-resistant properties, adding an extra layer of safety to your home. In the event of a fire, backer board can help slow down the spread, potentially saving lives and limiting property damage.
- Stability: Backer board offers remarkable dimensional stability, meaning it is less likely to expand or contract due to temperature changes. This characteristic ensures that your exterior siding remains intact and avoids cracks or other forms of damage that may occur with materials prone to expansion and contraction.
Limitations of Using Backer Board for Exterior Siding
- Appearance: While backer board provides excellent functionality, it may not offer the same aesthetic appeal as other traditional siding materials, such as stucco or vinyl. The rough texture and grayish color of backer board may not suit everyone’s taste.
- Installation Complexity: Installing backer board as exterior siding requires specialized knowledge and skills. The proper installation technique is crucial to ensure the durability and longevity of the siding. It is recommended to hire a professional installer experienced in working with backer board to achieve the best results.
- Additional Coating: Backer board needs to be coated with a waterproofing material and a high-quality exterior paint or finish to protect it from moisture infiltration, UV rays, and other environmental elements. The additional coating adds to the overall cost and maintenance requirements of using backer board as exterior siding.
While backer board is primarily designed as an underlayment for tile, it can be used for exterior siding with careful consideration of its benefits and limitations. The exceptional durability, fire resistance, and stability of backer board make it an attractive choice for homeowners seeking a long-lasting and reliable siding material. However, the appearance may not appeal to everyone, and installation complexity should be taken into account. It is advisable to consult with professionals and evaluate alternative siding materials before making a final decision. By weighing these factors, you can determine if backer board is the right choice for your exterior siding project.