What is the buttering-floating method and when should you use it?
Reading time: approx. 4 minutes
Large-format tiles are becoming increasingly popular, but they also demand a higher standard of installation. If voids are left beneath the tile, the risk of cracks, breakage and loose tiles increases significantly. The buttering-floating method, also known as double adhesive application, helps prevent these problems by supporting almost the entire surface of the tile.
What is the buttering-floating method?
The buttering-floating method is a tile installation technique in which tile adhesive is applied to both the substrate and the back of the tile.
- Floating: Apply a layer of adhesive to the substrate using a notched trowel.
- Buttering: Spread a thin layer of adhesive over the back of the tile.
Applying adhesive to both surfaces creates a larger contact area, minimises voids beneath the tile and improves the bond between the tile and the substrate. It also distributes loads more evenly across the tile.
Why is double adhesive application so important?
Ceramic tiles are extremely strong under compression but much less resistant to bending forces.
When a void exists beneath a large-format tile, that area lacks proper support. Under load—for example from furniture, dropped objects or heavy foot traffic the tile must absorb the force on its own. This creates high bending stresses that can cause the tile to crack or break.
For outdoor installations, voids present an additional risk. Water can collect beneath the tile and expand when it freezes, causing the tile to loosen or become damaged.
By using the buttering-floating method, almost the entire tile surface is fully supported, greatly reducing these risks.
When is the buttering-floating method recommended?
Double adhesive application is strongly recommended for:
- Large-format tiles (at least one side measuring 60 cm or more)
- Natural stone
- Outdoor installations
- Floors with underfloor heating
- Heavily loaded floors, such as shops, warehouses and public buildings
- Substrates with greater flatness tolerances
- Slightly bowed (convex) tiles
How should the adhesive be applied?
There are several ways to perform the buttering-floating method.
For example, when installing a 75 × 75 cm tile with a 12 mm notched trowel on the substrate, you can prepare the back of the tile by:
- applying adhesive with the same 12 mm notch size;
- spreading a smooth, continuous coat using the flat side of the trowel;
- applying adhesive with a smaller notch size, such as 8 mm.
The best approach depends on the tile, the substrate and the type of adhesive being used. In many situations, using a smaller notch on the back of the tile makes it easier to slide the tile into the adhesive bed while achieving excellent coverage.
Consider the finished floor height
The installation method you choose directly affects the final height of the tiled floor.
Applying a coarse notch size to both the substrate and the tile creates a thicker adhesive layer than applying only a smooth coat to the back of the tile.
This difference can be important around door thresholds, floor drains and adjoining floor finishes. Always consider the required adhesive thickness and finished floor level before starting the installation.
Choose the right tools
Successful buttering-floating starts with the right tools. Using a suitable notched trowel, a high-quality tile adhesive and a professional tile levelling system allows you to work faster, more accurately and achieve a durable installation.
At Nivello, you'll find everything you need for the professional installation of large-format tiles.
👉 Browse our adhesive notched trowels
👉 Discover our tile levelling systems
👉 Shop our complete range of tiling tools
