Backer boards are an essential component in many construction and remodeling projects, especially in areas where moisture or water exposure is prevalent, like bathrooms, kitchens, or laundry rooms. These boards serve as a stable and durable substrate for tile installations, acting as a barrier to prevent water damage and tile movement. However, not all types of backer boards are created equal when it comes to water resistance. In this article, we will explore the different types of backer boards available in the market and their varying degrees of water resistance.
1. Cement Backer Board
Cement backer board, also known as cementitious backer units (CBUs), is a widely used choice for tile installations. These boards are composed of Portland cement mixed with reinforcing fibers, often made of fiberglass mesh, to enhance their strength and durability. Cement backer boards are highly water-resistant and can withstand prolonged exposure to moisture without deteriorating.
The cementitious composition of these boards makes them inherently resistant to water, as cement does not absorb water like other materials. Additionally, the reinforcing fibers prevent the board from warping or delaminating when exposed to moisture, ensuring long-term stability and performance. However, it is important to note that although cement backer boards are highly water-resistant, they are not completely waterproof.
2. Fiber Cement Backer Board
Fiber cement backer boards, also known as FCUs, are similar to cement backer boards in composition but incorporate cellulose or wood fibers into the mix. These fibers add flexibility and prevent cracking, offering improved strength and resistance to impact. Fiber cement backer boards are also highly resistant to water and can handle high moisture areas effectively. However, like cement backer boards, they are still not completely waterproof.
3. Foam Backer Board
Foam backer boards are a lightweight and easy-to-install alternative to cement or fiber cement backer boards. These boards are typically made from extruded polystyrene or expanded polystyrene, known for their excellent thermal resistance properties. However, foam backer boards are not inherently water-resistant, as polystyrene material can absorb water and retain moisture if not protected properly. Therefore, foam backer boards require an additional waterproofing layer, such as a waterproof membrane or a liquid waterproofing coating, to ensure reliable water resistance.
4. Gypsum Backer Board
Gypsum backer boards, also known as gypsum-based backer boards or drywall cement boards, are made from a mixture of gypsum, water, and reinforcing additives. Gypsum boards are commonly used in interior walls for their fire-resistant properties, but they are not suitable for areas with high moisture content. Gypsum is a highly absorbent material and will deteriorate when exposed to water or prolonged moisture. As a result, gypsum backer boards should not be used in wet or humid environments or areas that require reliable water resistance.
While backer boards are essential for tile installations in moisture-prone areas, it is crucial to choose the right type of board for the specific project requirements. Cement backer boards and fiber cement backer boards offer excellent water resistance, making them suitable for most applications. Foam backer boards require additional waterproofing measures to achieve reliable water resistance. On the other hand, gypsum backer boards should be avoided in areas with high moisture content. Always refer to manufacturer guidelines and consult with professionals to ensure the appropriate selection and installation of backer boards for your project’s needs.