Tile over plywood vs cement board: What is the difference?
Whether you’re a DIY homeowner or a contractor preparing to install tile, the quest for choosing the optimal backing is an essential consideration. You want the tile to lay properly and to hold up for years into the future.
It brings us to the common dilemma of tile over plywood vs cement board: What is the difference?
The difference is precisely what you need to know to choose the right option. If you’re unsure about the superior material, you’re in the right place to learn.
Discard the advice of others and weigh the facts
Before we get started, the question of plywood vs cement board generates controversy among skilled carpenters and installers.
You can indeed use either plywood or cement board as an underlayment and both materials will hold up for years under the right conditions, but not everyone will tell you the whole story. Plywood is easier to work with.
It’s lighter and more flexible than cement board, and it’s easier to use when you’re going solo on an installation job.
The cement board is heavy and it takes two people to handle it in large sheets. It’s less convenient to work with, but it has properties that make it the better choice.
Some carpenters avoid it whenever possible because they don’t like the hassle of the weight or the high cost involved in the initial outlay. Some prefer to pay later when the materials fail and the job needs to be torn out and reinstalled.
In the end, it will be your choice, but know the differences between plywood and cement board that you should weigh before you decide.
We urge you to continue reading because it’s a choice that could affect your satisfaction down the road.
Properties of plywood: pros and cons
Plywood may look like a solid sheet of wood but it’s a material that is made from multiple layers of wood veneer called plies.
The plies are glued together with adhesive in adjacent layers that rotate the wood grain to 90-degree angles. Then plies are pressed into a flat sheet that is available in various thicknesses.
The front of the plywood sheet is covered with a layer for viewing and the back is less desirable. The middle or core of the plywood consisted of internal layers of crossbands to strengthen the integrity of the wood.
Plywood may contain plies of softwood, hardwood, or a combination of both. Plywood is summarized as a series of wood veneer layers glued and bonded together with strong adhesives.
It’s a superior choice for some building projects, such as construction, framing, and installing wood floors, but is it the best option for tile?
Advantages of tile over plywood
Strong and durable building material
High-grade plywood is strong and durable. It is available in various thicknesses and strengths. The durability depends on the grade.
Flexible, light, and easy to work with
Plywood is lighter than cement board and easier to manipulate for transport and positioning.
Available in varying quality grades
Plywood comes in various grades. It gives you the option of choosing the price you’re willing to pay with the option of upgrading to stronger and more durable products to enhance longevity.
Treated plywood is resistant to moisture damage
Some grades of plywood get treated with chemicals that create a barrier that resists the damage of high humidity and other types of moisture.
There are limitations, but higher grades of heavily treated plywood can last for years under humid conditions and marine applications.
Resistant to impact damage
Plywood is flexible enough to absorb the shocks and jars of typical impacts without cracking or breaking.
It has its limits but will hold up under significant jolts such as dropping a heavy item on a floor or striking a wall with a heavy object.
High strength-to-weight ratio
Plywood has a high strength-to-weight ratio which means it can withstand heavy loads without buckling or cracking.
Load-bearing ratings depend on the weight of the materials applied and the thickness of the plywood. The higher the grade and thickness the stronger the underlay.
Lower quality grades of plywood are cheaper than superior grades that are treated for chemical and water resistance.
The price advantage comes at the expense of durability and longevity. It’s an option that allows you to stay on a tight budget over higher-grade plywood or expensive cement board.
Stable surface integrity under temperature changes
High-quality grade plywood offers a stable surface that can withstand the swelling of the wood that occurs during high environmental temperatures.
Quality plywood also performs well when temperatures fluctuate from extreme heat to freezing temperatures.
Resistant to chemicals when preserved and treated
Treated plywood is more resistant to chemical damage than untreated plywood. High-grade plywood provides better resistance.
Disadvantages of use with tile
Untreated plywood is not waterproof
Untreated plywood is susceptible to damage from high humidity and moisture. Treated plywood is not 100% waterproof and may succumb to damage over time.
Plywood swells and contracts at a different rate than tile
Hot and cold temperatures cause wood products to contract when the temperatures drop. Wood material swells when temperatures rise.
It’s a constant natural event that happens with most building materials. The problem with matching tile and grout products with plywood is that the materials swell and contract at different rates, compromising adhesion.
Plywood is flexible
While the flexibility of plywood makes it easier to handle and manipulate, the characteristic is not ideal when pairing as an underlay for tile.
Any movement of the plywood beneath can crack grout and loosen the tile. The result is the crumbling of the grout and causing tiles to become vulnerable to damage or dislodging over time.
Plywood splinters and cracks when sawn
Plywood material is notorious for cracking and splintering when cut with power or hand tools.
The layers can become brittle and may present a problem when attempting to size the pieces. Chipped edges are difficult to work with when laying tile over the top.
Rough edges do not provide a smooth surface
Plywood has a rough finish. The material’s texture can interfere with the evenness of the tiles and can cause the adhesive to fail.
Not ideally suited for adhesion of the tile
Grout and tiles do not adhere to plywood as well as they do to cement boards. Low adhesion can cause tiles to become loose over time.
Weighing the pros and cons of tile over plywood
Reasons to put tile over plywood
Plywood is a strong and durable material with a lot going for it. The better grades are strong enough to hold the weight of tile applications without damage to the underlying surface.
It’s strong enough to keep the tiles in place for years without buckling.
If you’re willing to spend more on superior grades, it provides some resistance to moisture and temperature extremes.
It’s light and easy to transport and maneuver because of its flexibility. These are the advantages of using plywood as an underlying surface for tile.
Reasons not to put tile over plywood
You’ll spend more money on plywood treated for moisture resistance than on non-treated grades, but it will not be 100% waterproof.
It’s lighter and easy for one person to handle and move around, but it’s more difficult to cut without splintering and cracking.
The surface of plywood is rough and may present issues in the adhesion of the tile. Rough wood may require light sanding to smooth the surface.
The plywood expands and contracts at a different rate than tile and grout because of its different composition.
Wood responds to changes in temperature and humidity differently than other materials. The likelihood of grout cracking or loosening from adhesives increases with plywood.
Properties of cement board: pros and cons
The properties of cement boards are different than plywood. The boards consist of dissimilar materials, in most cases. The processes for making them differ.
Cement boards are flat boards made of cement, water, and particles or fibers for reinforcement. A mixture of them gets formed into sheets, then stacked, pressed, dried, and trimmed to various sizes.
Four types of cement boards are Fibre cement boards, Wood wool cement boards, Cement bonded particle boards and Wood strand cement boards.
Fiber cement board and Wood wool cement board are the two types recommended for tile backing because of the properties that make them durable underlay options.
Fiber cement board or FCB contains composite fibers. Carbon products or Kevlar are examples. These raw materials create strong boards that hold up for many years.
They’re also the more expensive alternatives. FCB made of recycled cellulose fibers is cheaper.
It has reduced water resistance with lower strength. It can lead to damage from freezes and thaws.
The lower grades of FBC and WWCB are environmentally friendly and more economical but not as strong as the more expensive alternatives. Similar to plywood, FCB comes in varying quality grades.
In the case of cement boards, the most expensive options are also the most durable.
It’s not a matter of brand name or prestige. The choice of buying high-grade materials is all about quality and durability.
You get what you pay for. Some manufacturers offer fiber cement board products with a 50-year guarantee and the promise that it’s manufactured with sustainable processes.
Advantages of fiber cement board
Resistant to impact and durable
Fiber cement board is sturdy due to the reinforcing fibers and pressure treatment.
The process compacts them together and bonds the fibers for strength that can bear heavy loads without cracking or crumbling.
The properties of cement boards make them highly resistant to fire. None of the elements used in its creation are flammable. Most manufacturers include fire-retardants in the mix before pressing.
Resistant to moisture and decay
The components of fiber cement board make it highly resistant to moisture damage and the resulting deterioration.
Rigid, less flexible
The cement board is more rigid than plywood. It may be harder to work with because of its lack of flexibility, but it won’t move or bend after installation.
The stiff properties hold grout and til in place without movements that can potentially cause grout cracking, crumbling, and tile dislodgement.
Some types of cement boards come from environmentally-friendly processes. Its components pose little risk to the environment
Cement board has a longer lifespan than plywood. It holds up for years. Some brands of cement boards come with 50-year warranties.
Disadvantages of fiber cement board
Cement board is more expensive than plywood. The recommended grade of cement board is high-quality fiber cement board that
Heavier than plywood/requires 2 persons to handle
The cement board is heavier than plywood. It may require 2 persons to move from one spot to another because of the weight. It’s more difficult to maneuver because of the combination of weight and rigidity.
Wood wool cement board advantages
Wood wool cement board is resistant to fire because of flame-retardant ingredients in the mixture. The material is less combustible than plywood.
Moisture, fungus, freeze-thaw, and vermin resistant
Both types of cement boards resist the damage from moisture, fungus, and the expansions of the materials that come with changing temperatures.
The expansion and contraction rates are similar to that of grout and tile for a more harmonious marriage of the materials.
The cement board is also resistant to vermin. Rodents can chew through plywood, but destructive pests cannot chew holes into material.
The hardness of fiber cement board deters rats, mice, and other vermin that can crawl behind walls and cause damage to homes.
Advantages of wool and wood Cement board
Lower cost over fiber cement board
Wood wool cement board. is cheaper than fiber cement board but still more expensive than plywood.
Lower weight than fiber cement board
Wood wool cement board is lighter than fiber cement board but heavier than plywood
Disadvantages of tile over wool and wood cement board
Low bending strength and elasticity
Low bending strength and elasticity are good for rigidity, but it is not as strong as fiber cement board.
It breaks more easily. You can shatter the board by dropping it because of its weight.
Cement board is more expensive than plywood
The price is far higher than plywood. Wood wool boards are less expensive than fiber cement boards but sacrifice quality and advantages
Heavier than plywood
Although wood wool cement board is lighter than fiber cement board, it is still far heavier than plywood.
Reasons to put tile over cement board
Cement board is a durable material that is suitable for use as an underlay for tile applications.
The smooth surface provides the ideal surface texture for squaring tile with even heights. The surface accepts and retains adhesives for longer than plywood.
Cement board has higher longevity of up to fifty years. It is resistant to fungus, vermin, moisture, and expansion and contraction damages.
Cement board is the material to choose if you want to use the most suitable material with the most benefits for applying grout and tile for walls and floors that last longer than tile over plywood. Cement board cuts with lower chipping and splintering risk than plywood.
Reasons not to put tile over cement board
Some carpenters opt for plywood over cement board because of the initial expense involved. The cement board is expensive, and it’s heavy to move around. It requires two people to maneuver it.
A cheaper version is available, but the wood and wool type doesn’t provide the long-term advantages of the more expensive fiber cement board type.
Two main reasons for avoiding tile over cement board are the cost and difficulty moving it around. Aside from these two drawbacks, it’s the most suitable material for underlying tile applications.
Fiber cement board has the most to offer if you want to use an underlying material for tile that will last the longest and present the least amount of problems.
It’s heavy and expensive, but the cost is mitigated by the longevity of the finished project when installing tile.
Plywood is the cheaper route that is lighter and easier to maneuver, but it has more drawbacks than cement board.
It’s a matter of personal preference and budgeting, but cutting corners on home projects usually costs more in repairs and remodels in the long term.