When planning a tile installation project, choosing the right substrate is crucial for ensuring durability and longevity. The debate between using plywood or cement board as a substrate has significant implications for project cost, installation difficulty, and the finished product’s performance. This choice affects not only your immediate budget but also the long-term integrity of your tiled surface. Understanding the differences between these two popular options helps homeowners and contractors make informed decisions based on specific project requirements, location, moisture exposure, and budget constraints.
A tile substrate provides the foundation upon which tiles are installed. The substrate must be stable, level, and appropriate for the specific conditions where the tiles will be placed. Plywood and cement board represent two distinct approaches to creating this foundation.
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Plywood is an engineered wood product made by gluing together thin layers of wood veneer. For tiling purposes, exterior-grade plywood is typically recommended, especially ACX-grade which offers water resistance. In contrast, cement board (also called backer board) is made from cement, reinforced with fiberglass mesh on both sides, creating a moisture-resistant, stable surface specifically designed for tile installation.
Plywood as a Tile Substrate: Overview
Plywood has been used as a tile substrate for decades, particularly in drier areas of homes. Typically, a minimum thickness of ¾ inch is required for floor applications to prevent deflection (the slight bending that occurs when weight is applied to the floor).
When used for tiling, plywood should be installed in two layers: a base structural layer and a top layer. The top layer is typically a minimum of ½ inch thick, installed perpendicular to the base layer with joints staggered to enhance stability. Modern plywood options for tiling include specialty products that offer enhanced moisture resistance and stability specifically engineered for tile underlayment.
Types of Plywood for Tile Installation
- Exterior-grade plywood (ACX)
- Marine-grade plywood
- Tongue and groove plywood
- Specialty tile underlayment plywood
Cement Board as a Tile Substrate: Overview
Cement board has become the industry standard for tile installation, particularly in wet areas. It provides a dimensionally stable substrate that won’t warp, rot, or deteriorate when exposed to moisture. Typically available in thicknesses ranging from ¼ inch to ½ inch, cement board creates a solid, inflexible base for tile.
The material’s composition makes it impervious to water damage, preventing the growth of mold and mildew beneath tiles. Cement board also creates a strong mechanical bond with thinset mortar, enhancing the adhesion of tiles to the substrate. While heavier and more difficult to cut than plywood, cement board offers superior long-term performance in most tiling applications.
Common Types of Cement Board
- Traditional cement board (Portland cement with fiberglass mesh)
- Lightweight cement board
- Foam-core cement board
- Glass-mat gypsum boards (technically not cement board but often used similarly)
Price Comparison: Plywood vs Cement Board
Plywood typically costs between $15-$45 per 4×8-foot sheet, depending on quality and thickness. Standard exterior-grade plywood suitable for tiling runs approximately $25-$35 per sheet. Specialty tile underlayment plywood may cost more.
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Cement board prices range from $10-$15 per 3×5-foot sheet for standard options, with premium and specialty products costing up to $25 per sheet. When calculated by square foot, cement board typically costs $0.65-$1.50 per square foot while plywood ranges from $0.50-$1.40 per square foot.
| Material | Average Cost per Sheet | Average Cost per Square Foot |
|---|---|---|
| Standard Plywood (3/4″) | $25-$35 (4×8 ft) | $0.78-$1.09 |
| Premium Plywood | $35-$45 (4×8 ft) | $1.09-$1.40 |
| Standard Cement Board (1/2″) | $10-$15 (3×5 ft) | $0.65-$1.00 |
| Premium Cement Board | $15-$25 (3×5 ft) | $1.00-$1.50 |
Installation Costs and Process
The cost of professional installation varies significantly between plywood and cement board. Professional installation of plywood underlayment typically ranges from $2-$4 per square foot, including materials and labor. Cement board installation generally costs $4-$7 per square foot when professionally installed.
The installation process for plywood is generally straightforward, requiring standard woodworking tools and fasteners. Cement board installation requires specialized tools for cutting (such as a score-and-snap tool or power saw with dust collection), special screws, and thinset mortar beneath the boards. The additional materials and more complex installation contribute to the higher installation cost.
Additional Installation Materials
- For Plywood: Construction adhesive, screws, seam tape (optional)
- For Cement Board: Thinset mortar, alkali-resistant fiberglass tape for seams, specialized screws, waterproofing membrane (for wet areas)
Top Brands for Plywood and Cement Board
Leading plywood brands for tile underlayment include Georgia-Pacific, Weyerhaeuser, and PureBond. These manufacturers produce high-quality, dimensionally stable plywood products with consistent performance. For specialized tile underlayment plywood, brands like Columbia Forest Products offer products specifically engineered for tiling applications.
Top cement board brands include HardieBacker (James Hardie), Durock (USG), WonderBoard (Custom Building Products), and PermaBase (National Gypsum). Each brand offers slightly different formulations and features, with variations in weight, water resistance, and ease of cutting. USG’s Durock and James Hardie’s HardieBacker dominate the market with widespread availability and proven performance records.
| Brand | Material Type | Notable Features | Average Price Range |
|---|---|---|---|
| HardieBacker | Cement Board | Lightweight, high score on moisture resistance tests | $12-$17 per 3×5 ft sheet |
| Durock | Cement Board | Industry standard, excellent durability | $10-$15 per 3×5 ft sheet |
| Georgia-Pacific | Plywood | Consistent quality, widely available | $25-$35 per 4×8 ft sheet |
| PureBond | Plywood | Formaldehyde-free, environmentally friendly | $35-$45 per 4×8 ft sheet |
Pros and Cons of Using Plywood for Tile Installation
Pros of Plywood
- More economical for large areas and dry spaces
- Lighter weight, making it easier to transport and handle
- Can be cut with standard woodworking tools
- Provides some flexibility that can be beneficial in certain applications
- Faster installation in most cases
- Readily available at most hardware stores
Cons of Plywood
- Susceptible to moisture damage, which can lead to warping and tile failure
- Not recommended for wet areas like bathrooms and showers
- May require additional waterproofing membranes
- Less dimensional stability over time
- Generally shorter lifespan in tiling applications
- May void tile warranties if used in inappropriate applications
Pros and Cons of Using Cement Board for Tile Installation
Pros of Cement Board
- Superior moisture resistance, making it ideal for wet areas
- Extremely stable with minimal expansion and contraction
- Creates excellent mechanical bond with thinset mortar
- Prevents mold and mildew growth
- Longer lifespan for tile installations
- Accepted by all tile manufacturers, preserving warranties
Cons of Cement Board
- Heavier and more difficult to handle than plywood
- Requires specialized cutting tools
- More expensive for large installations
- Creates significant dust when cut
- More complex installation process
- Less forgiving of structural movement
Which Substrate is Best for Different Applications
For bathrooms, showers, and other wet areas, cement board is unquestionably the superior choice. Its water resistance and dimensional stability make it ideal for environments with frequent moisture exposure. Most professional installers and building codes require cement board for shower walls, tub surrounds, and bathroom floors.
For dry areas with stable subfloors, plywood can be appropriate and more economical. Kitchens, dining areas, and living spaces that won’t experience significant moisture can perform well with properly installed plywood substrates. However, many professionals still prefer cement board for all tiling applications due to its superior stability and longevity.
Application-Based Recommendations
- Shower walls: Cement board with waterproofing membrane
- Bathroom floors: Cement board
- Kitchen backsplash: Either option (cement board preferred)
- Kitchen floors: Either option (cement board preferred near sinks/dishwashers)
- Living areas: Either option depending on budget and performance expectations
Installation Tips for Both Options
When installing plywood for tiling, always use two layers with joints staggered and not coinciding with the subfloor joints. Screw the plywood every 6-8 inches across the surface and every 4-6 inches along the edges. Leave a â -inch gap between sheets for expansion and use exterior-grade screws.
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For cement board installation, apply a layer of thinset mortar beneath the board before fastening. Use alkali-resistant fiberglass tape and thinset to treat all seams. Install cement board with a ¼-inch gap at walls and fixtures and â -inch between sheets. Use specialized cement board screws placed every 6-8 inches, keeping screws at least â -inch from edges.
Regardless of which substrate you choose, ensuring a flat, level surface is critical. Neither material can correct significant subfloor problems, so address any major issues before installation. For both materials, acclimation to the installation environment for at least 24 hours is recommended to minimize potential movement after installation.