What Type of Thinset to Use When Tiling Over Tiles?

Tiling over tile is a tricky job, and without the right product it is a fool’s errand. Although tiling over tile is not a highly recommended thing, sometimes it’s done in unavoidable circumstances. Tiling experts advise people to get rid of their existing tiles completely before laying new tiles, but sometimes, that job turns out too challenging. For instance, tiles that are still in excellent condition are not easy to remove with a little pry and a pound. When that happens, little option remains other than to move forward with the installation without removing the older layer. However, if you are planning to tile over tiles, make sure that you are following the right steps and using the right set of products for the job.

Choosing the right thinset is crucial for tiling over tiles because it provides the adhesive bond between the new tiles and the existing substrate. The high-performance, flexible, thinset mortar is specifically designed to bridge any gaps or irregularities between the two surfaces and provide a strong, durable bond. Using the wrong type of thinset can result in a weak bond, which can lead to tile failure and other problems.

Factors to Consider When Choosing Thinset for Retiling

In addition to the factors you’ve mentioned, here are some other important considerations when selecting thinset for retailing:

Substrate Condition:

Existing tile conditions: If the existing tiles are cracked, chipped, or loose, a stronger thinset may be required to ensure a secure bond.
Substrate strength: The strength of the underlying substrate (e.g., concrete, plywood) will influence the thinset’s ability to provide adequate support.

Tile Type and Size:

Tile weight: Heavier tiles, such as porcelain or natural stone, will require a thinset with greater adhesive strength.
Tile size: Larger tiles may require a thinset with improved flexibility to accommodate any slight movement or settling.

Project Environment:

Temperature and humidity: Extreme temperature fluctuations or high humidity can affect the curing process and the thinset’s performance.
Moisture exposure: If the retiling area is exposed to moisture, a water-resistant thinset should be used to prevent mold and mildew growth.

Specific Requirements:

Radiant heating: If radiant heating is present, a thinset specifically designed for this application should be used to avoid cracking.
Chemical resistance: If the retiling area is exposed to chemicals, a thinset with appropriate chemical resistance is necessary.

Understanding Thinset

Thinset is a mortar used to adhere ceramic, porcelain, and natural stone tiles to a substrate. It acts as an adhesive, providing a strong bond between the tile and the underlying surface.

Role of Thinset in Tile Installation

Thinset serves several crucial roles in tile installation:

Adhesion: It provides the primary bond between the tile and the substrate, ensuring the tiles remain securely in place.
Leveling: Thinset helps to create a smooth and even surface for the tiles, preventing unevenness and potential cracking.
Support: It provides structural support for the tiles, distributing the weight evenly across the substrate.

Types of Thinsets

Thinsets are available in various types, each with its specific properties and applications. Some common types include:

Unmodified Thinset: This is a basic type of Thinset suitable for most residential applications. It is typically made from Portland cement, sand, and water.
Polymer-Modified Thinset: This type of thinset contains additives that improve its flexibility, adhesion, and resistance to cracking. It is often used for outdoor applications or in areas with high moisture levels.
Latex-Modified Thinset: This thinset contains latex additives that enhance its flexibility and adhesion. It is well-suited for both indoor and outdoor use.
High-Performance Thinset: This type of thinset is designed for demanding applications, such as commercial settings or heavy-duty flooring. It offers superior strength, durability, and resistance to cracking.
Anti-Cracking Thinset: This thinset is specifically formulated to prevent cracking in areas where movement or vibration is expected. It is often used in areas with radiant heating or over existing tile.

Below are some suggestions for the types of thinset you want to use for this specific job.

Laticrete 254 Platinum Thinset

If you have thin porcelain tiles in mind, then there isn’t a thinset mortar that can beat the performance of the Laticrete 254 Platinum. Especially ideal for porcelain tiles that are thin and light, this thinset spreads easily and evenly creating a strong and lasting bond between the new and old tiles. Providing the ultimate adhesive for porcelain tiles as well as glass ones, this mortar is formulated with anti-microbial technology that offers protection against any microbial build-up on the tiles.

Now the Laticrete 254 PLATINUM Multipurpose Thinset Mortar is what you want to especially consider if this is an exterior area or a place that remains submerged. With excellent shear bond strength, the thinset makes sure that the tiles sit snugly in their grooves impervious of the moisture in the environment. A number of color options makes this grout an easy choice for unique colored tiles.

Laticrete 253 Gold Multipurpose Thinset

The next choice in line is the Laticrete 253 Gold Multipurpose thinset. A superior powder polymer, this is another great product that is easy to work with. Just mix it with water and its ready to apply. A thinset mortar formulated for ceramic and stone tiles, the 253 Gold is a highly recommended product for tiling over tile projects. What makes this product especially suitable for the job in question? It’s bonding strength. 253 Gold thinset is among the few thinset mortars in the market that bond with any surface. The 253 indeed has the reputation for bonding with most kinds of substrates involved in tiling.

Speaking of the suitability of applications, this product can be used for both indoor and outdoor installations. So, you can use it confidently for both kinds of applications. The 253 Gold meets and exceeds the bond requirements of ANSI A118.4 which if you know anything about bonding strength is excellent. Mixed with water, it assumes a smooth and creamy consistency that is easy to spread on any surface. The special antimicrobial formula protects the surfaces from mold and mildew.

4237 Thinset Mortar Additive

A mortar additive you absolutely want to check out when shopping for additives for tiling over tile, the 4237 thinset has a great reputation for its exceptional bond strength. The product has 250% greater bond strength compared to the ANSI A118.4 standard. It is flexible, not to mention shock resistant, which makes it the most ideal additive to use in high-traffic areas. The product is resistant to frost and other weather elements, which is good news for those looking for a product for exterior application. With its proven performance, the 4237 is the most recommended latex additive for thinset for the concerned kind of installations.