Do I Have To Put Cement Board Under Tile

Do I Have to Put Cement Board Under Tile?

When it comes to tiling, the question of whether or not to use cement board as a backer board often arises. Cement board, also known as backer board or tile backer, is a popular choice for use under tile installations, but there are certain factors to consider before deciding. In this article, we will delve into the essential aspects of using cement board under tile.

Benefits of Using Cement Board

Moisture Resistance: Cement board is highly resistant to moisture, making it an ideal choice for areas prone to moisture, such as bathrooms, kitchens, and outdoor spaces. It will not absorb water or swell, which can cause tiles to become loose or crack.

Strength and Durability: Cement board is strong and durable, providing a solid and stable surface for tile installation. It helps distribute the load of the tile and adhesive, reducing the risk of cracking or breaking.

Fire Resistance: Cement board is non-combustible, making it a safe choice for use in areas where fire safety is a concern.

When is Cement Board Necessary?

While cement board offers many benefits, it is not always necessary in all tile installations. There are certain situations where it is highly recommended or even required:

Wet Areas: In areas exposed to moisture, such as bathrooms, showers, kitchens, and mudrooms, cement board is essential to prevent water damage to the subfloor and tiles.

Unstable Subfloors: If the subfloor (e.g., plywood, concrete) is uneven, weak, or has defects, cement board can provide a smooth and level surface for tile installation.

Large Tile Installations: When large tiles (e.g., 12 x 12 inches or larger) are used, cement board is recommended to ensure proper support and prevent cracking.

When is Cement Board Not Necessary?

In certain situations, cement board may not be necessary:

Dry Areas: In areas with low moisture exposure, such as living rooms, bedrooms, or dining rooms, cement board may not be essential. However, if the subfloor is uneven or weak, it could still be beneficial.

Small Tile Installations: For small tile installations (e.g., 4 x 4 inches or smaller), cement board may not be necessary if the subfloor is in good condition.

Installation Considerations

If you decide to use cement board, it is important to install it properly to ensure the longevity of your tile installation:

Use Thinset Mortar: To install cement board, use thinset mortar, which is a specially formulated adhesive specifically designed for tile installations. Do not use regular mortar.

Screw Securely: Cement board should be screwed securely to the subfloor using appropriate fasteners, such as galvanized screws or fiber cement backer board screws.

Seal Joints: After the cement board is installed, use a water-resistant sealant to seal the joints and edges to prevent moisture penetration.

Conclusion

Whether or not you need to use cement board under tile depends on various factors, including the location, size of the tiles, and condition of the subfloor. If moisture resistance, strength, and durability are important considerations, cement board is a reliable choice. However, if these factors are not a concern and the subfloor is adequate, it may not be necessary for all tile installations.