Choosing the right tile underlayment is essential for a beautiful, long-lasting installation.
Tile underlayment materials provide a stable, even surface for your tiles and add extra sound and temperature insulation.
With so many options available, it’s important to consider the type of tiles you’re using and the specific needs of your installation project.
Cement-based backer boards, such as DensShield, Hardiebacker, and WonderBoard, are widely regarded as the top underlayment choice for ceramic tiles in various applications, including floors, walls, and countertops.
These backer boards provide a durable, moisture-resistant surface that works well with ceramic tiles.
Be sure to check the compatibility of your chosen underlayment with your tile adhesive to ensure a successful installation.
Other popular underlayment options include oriented strand board (OSB), made from large wood chips and suitable for certain flooring applications.
Additionally, materials such as foam, felt, cork, rubber, and recycled materials offer different benefits depending on the type of flooring and the project specifications.
Carefully researching and selecting the right underlayment for your tile project will help create a stellar result that lasts years.
1. Essential Features of Best Tile Underlayment
When choosing the best tile underlayment for your project, it’s important to consider key factors that will ensure the longevity and attractiveness of the finished project.
Moisture Resistance
One of the most critical factors to consider when choosing tile underlayment is its moisture resistance capabilities.
Underlayment designed to resist water and moisture can help protect your tile installation from damage caused by dampness and excessive humidity.
This feature is particularly important if you’re installing tile in rooms exposed to water, such as bathrooms, kitchens, or outdoor spaces.
In addition to protecting the integrity of your tile flooring, moisture resistance can also prevent mold and mildew growth, which are known to cause health problems and create unpleasant odors.
Consider choosing underlayment materials that perform well in damp environments, keeping the spaces in your home healthy and looking their best.
Ability to Mask Subfloor Irregularities
No subfloor is perfectly flat, and it’s vital that the underlayment you choose can effectively mask any irregularities in the existing surface.
The best tile underlayment should provide a smooth, even surface for the tile installation, reducing potential issues such as lippage or unevenness that can result in an unsightly and unsafe finished product.
To make sure your underlayment will adequately mask irregularities, it’s essential to measure the level of the subfloor.
For tiles with at least one edge 15 inches or longer, the maximum allowable variation should be no more than 1/8 inch in 10 feet and no more than 1/16 inch in 2 feet.
Select an underlayment that will achieve a sufficient level of flatness for your particular subfloor conditions.
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2. Types of Tile Underlayment
Backer Boards
Backer boards are an industry standard for installing ceramic or porcelain tile. Construction professionals widely prefer them, and they come in various sizes, the most common being a four-foot-by-eight-foot sheet.
This underlayment provides a strong, stable surface for your tile installation.
Uncoupling Membranes
Uncoupling membranes are an effective underlayment for tile installation as they help prevent movement or stress from the subfloor transferring to the tile, avoiding cracks and other damage to your tiles.
These membranes are typically made from plastic and are both waterproof and lightweight.
Mortar Beds
Mortar beds are a traditional method of tile underlayment that provides a solid, level surface for your tiles.
While this technique can be more time-consuming and labor-intensive than newer methods, it can work very well for certain installations, especially in areas where water exposure or uneven flooring is a concern.
Self-Leveling Underlayments
If you’re dealing with an uneven subfloor, self-leveling underlayments can be an excellent solution. These underlayments are applied as a liquid that levels itself out, creating a consistent surface.
This makes it much easier to install your tiles, ensuring they’re aligned and properly seated.
Foam Backer Boards
Foam backer boards are a lightweight and easy-to-install option for tile underlayment. They are made from extruded or expanded polystyrene and have a smooth, level surface perfect for tiling.
Foam backer boards offer excellent thermal and moisture insulation, making them a great choice for areas prone to dampness.
Liquid Membranes
Liquid membranes, such as RedGard, are waterproofing and crack-prevention barriers beneath your tiles. Before tile installation, they’re applied directly to your subfloor with a brush or roller.
Ensuring full coverage and correct thickness is essential for the best results is essential.
This underlayment is especially helpful in areas where moisture or potential water damage is a concern, like bathrooms or kitchens.
3. Tile Underlayment for Different Subfloors
Wood Subfloors
Regarding wood subfloors, exterior plywood is popular for your tile underlayment.
This is because the bonding adhesives used in exterior plywood are waterproof, which helps prevent the wood from swelling if water seeps through the tile installation.
In comparison, interior-grade plywood is not recommended due to its vulnerability to water damage.
To prepare your wood subfloor, ensure it’s clean, flat, and debris-free. If needed, use a leveling compound to correct any uneven areas.
Once the subfloor is ready, apply your chosen underlayment material according to the manufacturer’s instructions, ensuring a smooth and even surface for your tiles.
Concrete Slabs
Concrete slabs can also serve as a suitable base for your tile underlayment. However, inspecting the slab for any cracks or uneven areas before proceeding is essential.
If you find any issues, use a patching compound to fill and repair the cracks, and utilize a leveling product to address any unevenness.
In most cases, you can install tiles directly over a concrete slab using thinset mortar as long as the surface is flat and crack-free.
However, consider using a dedicated tile underlayment product to provide a more robust and long-lasting installation, especially in areas prone to moisture.
These products help to ensure a smooth, even, and moisture-resistant foundation for your tiles.
4. Tile Underlayment for Different Types of Tiles
Ceramic Tiles
Ceramic tiles are versatile and lightweight, which makes them a popular option for many home projects. You can use backer board as the underlayment for ceramic tiles.
This industry-standard material offers excellent support and water resistance, perfect for rooms with moisture exposure, such as bathrooms and kitchens.
When installing ceramic tiles over a wood subfloor, use exterior-grade plywood.
This type of plywood is suitable as an underlayment because it has waterproof bonding adhesives, preventing swelling due to water exposure.
Porcelain Tiles
Porcelain tiles are a premium choice for many homeowners, known for their durability and low maintenance. Like ceramic tiles, the most recommended underlayment option for porcelain tiles is backer board.
This material provides excellent durability and water resistance, ensuring a long-lasting installation in moisture-prone areas.
As with ceramic tiles, choosing exterior-grade plywood for wood subfloor installations is important.
This will ensure that the underlayment remains stable if water seeps through the tile installation.
Stone Tiles
For natural stone tiles such as granite, marble, or travertine, choosing an underlayment that provides maximum support to accommodate their heavy weight is important.
Again, using a backer board is an effective choice as it offers a sturdy and water-resistant base for stone tile installations.
If you have a wood subfloor, opt for an exterior-grade plywood. This material is waterproof and won’t swell when exposed to water, ensuring the stability of your stone tiles.
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5. Installation Process of Tile Underlayment
Leveling
Before starting the installation, you must ensure that your subfloor is clean and level. Remove debris or dust and fill in low spots with a leveling compound.
A level surface will help you create a stable and even foundation for your tile underlayment.
Applying Thinset Mortar
Mix the thinset mortar according to the manufacturer’s directions to begin installing the underlayment. Use a notched trowel to spread the mortar evenly onto the subfloor, covering a small section at a time.
The size and type of the notches in your trowel depend on the underlayment and tile, so refer to the manufacturer’s recommendations.
Laying Down Membranes
After applying the thinset mortar, it’s time to lay down the underlayment membranes. Start at one corner and unroll the membrane onto the freshly placed thinset, ensuring no wrinkles or air bubbles.
Use a push-type trowel or a roller to press the membrane firmly into the thinset for proper adhesion.
Repeat this process, working in small sections, and ensure the seams between the membranes are tightly butted together.
Final Adjustment and Adhesion
Once all the membranes are in place, walk over the entire surface to further compress the thinset mortar and ensure proper adhesion.
Check for any lumps or uneven areas, and use a trowel or roller to smooth them out. Allow the thinset to cure per the manufacturer’s guidelines before proceeding with your tile installation.
6. Top Rated Tile Underlayment Brands
Ditra
Ditra is a popular underlayment option made by Schluter Systems. It is a lightweight, easy-to-install, uncoupling membrane that supports your tiles.
The unique design of Ditra allows for a flexible and strong bond between the tile and the substrate, reducing the risk of tile damage due to movement in the subfloor.
It’s a great choice for various applications, including on top of wood or concrete subfloors.
Wonderboard
Wonderboard is a cement-based backer board that can be used as a tile underlayment.
It offers a durable, water-resistant surface for your tiles, making it perfect for areas exposed to moisture, such as bathrooms and kitchens.
Wonderboard is relatively easy to cut and install and provides a strong, stable base for ceramic, porcelain, and natural stone tiles.
Durock
Durock is another cement-based backer board that works well as a tile underlayment. Manufactured by USG, it is made with a high-performance core and offers excellent dimensional stability and durability.
Durock is resistant to mold and moisture, making it a suitable option for interior and exterior tile installations.
It is compatible with various types of tiles and can be used on walls, floors, and countertops.
Kerdi
Kerdi is a waterproofing membrane produced by Schluter Systems, explicitly designed for use in wet areas like showers and steam rooms.
While it is not a traditional underlayment, it is often used with Ditra or other underlayments to provide extra protection for your tiles and subfloor.
Kerdi is lightweight, flexible, and easy to install, making it a great option for maintaining the integrity of your tile installation in moist environments.
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Frequently Asked Questions
What is the best underlayment for ceramic tiles?
A backer board is an industry standard and the most preferred option for ceramic tiles. This four-foot-by-eight-foot board ensures a strong and stable base for your installation, preventing tile breakage and other issues.
Which underlayment is ideal for porcelain tiles?
Porcelain tiles also work well with backer board underlayment, providing a firm foundation for the tiles. Choosing an underlayment compatible with this type of tile is essential, especially when working with large-format tiles.
What type of underlayment works well on plywood?
When installing tiles on plywood, exterior-grade plywood is preferred as it is more resistant to water damage. In this case, using a water-resistant or uncoupling membrane can help ensure tile longevity and prevent moisture-related issues.
Which underlayment is recommended for bathroom tiles?
For bathroom tiles, using an underlayment that can handle moisture and prevent water damage is crucial. This can be achieved with waterproof backer boards, uncoupling membranes, or a moisture-resistant membrane such as Schluter’s Ditra.
What benefits does an uncoupling membrane provide?
An uncoupling membrane offers several advantages, including minimizing lateral movement stress between the tile and substrate, providing effective moisture management, and reducing the possibility of tile cracks. It also allows for faster and easier tile installation with its self-adhesive capabilities.
How does Schluter’s underlayment compare to others?
Schluter underlayment products like Ditra and Kerdi offer excellent performance and durability. They provide a waterproofing layer, uncoupling, and crack isolation features and are designed to be lightweight yet robust. Compared to other underlayments, Schluter products are highly regarded for their quality and effectiveness in challenging installations, making them an excellent choice for various tile projects.
