How many bags of adhesive do I need for 10m² of floor tiles?

For 10m² of floor tiling using a 10mm notched trowel, you will typically need about 25kg to 30kg of adhesive. This equates to roughly 1.5 standard 20kg bags.

What size trowel notch should I use for wall tiles?

For standard wall tiles (e.g., 200x300mm), a 6mm or 8mm notched trowel is usually sufficient. Larger wall tiles or tiles with a textured back may require a 10mm trowel to ensure full coverage.

What is 'flexible' tile adhesive and do I need it?

Flexible adhesive contains polymers that allow for slight movement. In the UK, it is essential if you are tiling over underfloor heating, plywood subfloors, or in any area subject to thermal expansion, to prevent your tiles from cracking.

How much adhesive do I need for 'back buttering'?

Back buttering involves spreading a thin layer of adhesive on the back of the tile as well as the substrate. This is standard for large format tiles (over 600mm) and adds about 20% to your total adhesive consumption.

How many bags of adhesive do I need for 10m² of floor tiles?

For 10m² of floor tiling using a 10mm notched trowel, you will typically need about 25kg to 30kg of adhesive. This equates to roughly 1.5 standard 20kg bags.

What size trowel notch should I use for wall tiles?

For standard wall tiles (e.g., 200x300mm), a 6mm or 8mm notched trowel is usually sufficient. Larger wall tiles or tiles with a textured back may require a 10mm trowel to ensure full coverage.

What is 'flexible' tile adhesive and do I need it?

Flexible adhesive contains polymers that allow for slight movement. In the UK, it is essential if you are tiling over underfloor heating, plywood subfloors, or in any area subject to thermal expansion, to prevent your tiles from cracking.

How much adhesive do I need for 'back buttering'?

Back buttering involves spreading a thin layer of adhesive on the back of the tile as well as the substrate. This is standard for large format tiles (over 600mm) and adds about 20% to your total adhesive consumption.

Tile Adhesive Calculator

Precision bag estimation for professional UK tiling results.

Total Tiling Area (m²)

Trowel Notch Size (mm)

Waste Factor (%)10%

Adhesive Estimate

Back Buttering? For large format tiles, you should apply adhesive to the back of the tile as well. Add 20% to your estimate for this.

Tiling Masterclass: Adhesive Choice & Coverage

Getting the Bond Right

Tile adhesive is the most critical component of your installation. It doesn't just hold the tile up; it must withstand thermal changes, moisture, and foot traffic. Running out mid-job can lead to the adhesive 'skinning over,' resulting in a poor bond.

Our tile adhesive calculator accounts for the "notch size" of your trowel—the single most important factor in determining how much material you will consume per square metre.

Trowel Coverage Specs

6mm Notch~1.5kg / m²

10mm Notch~2.5kg / m²

Standard Bag20kg

Trowel Selection

The rule of thumb for trowels in the UK is:

1
Small Wall Tiles (Subway/Metro): Use a 6mm square notch trowel.
2
Standard Floor Tiles: Use a 10mm or 12mm square notch trowel to ensure better coverage and bed depth.

Back Buttering

For large format porcelain tiles (600x600mm and above), "back buttering" is essential. This involves skimming the back of the tile with a thin layer of adhesive to ensure 100% coverage and eliminate voids.

Ready-Mixed vs Powder

Ready-mixed adhesive is only suitable for small wall tiles in non-wet areas. For floor tiling and any large format tiles, you MUST use a powder-based adhesive that you mix yourself.

Pro Tip: Flexible Adhesive

If your floor has underfloor heating, always buy adhesive marked as **"S1" or "S2" flexible**. This allows the adhesive to absorb the expansion and contraction caused by heat without the bond failing.

Tile Adhesive FAQ

Technical Disclaimer

Adhesive coverage depends heavily on the flatness of the substrate. If your floor or wall is uneven, you will use significantly more material to "level out" the surface as you go.