Which tile adhesive to use for floors, C1 or C2?

On floors, just as on walls, the wrong adhesive doesn't always fail at the moment of laying: it may take months to show, when some tile starts to sound hollow underfoot.

When C1 is enough and when C2 is needed

• C1, standard: consumption of 4.5 kg/m². Enough for conventional ceramic paving on a firm substrate.
• C2, improved/large format: consumption of 6 kg/m². Necessary with large-format or low-absorption tiles, where C1 doesn't give enough adhesion.

Calculation example: for 22 m² with C2 adhesive: 22 × 6 = 132 kg, rounding up to 6 bags of 25 kg. This is the same calculation the PresupuestoYa calculator applies automatically for the Floor Layer trade.

A useful tip if you work alone

Besides the C1/C2 class, consider an adhesive with extended open time if you work alone: it gives more margin to place the tile before the adhesive starts to form a surface skin, which reduces the risk of poor adhesion from working against the clock.

Glued vinyl: a different adhesive from ceramic

For glued vinyl plank or tile (as opposed to the floating click system), thin-spread contact adhesive consumes 0.4 kg/m². The glued system gives a more stable result in heavy-traffic areas or with wheels (offices, shops) than the floating click system, at the cost of being more laborious to remove if it has to be changed in future.

Frequently asked questions

How much C1 tile adhesive do I need for 15 m² of standard floor? 15 × 4.5 = 67.5 kg, rounding up to 3 bags of 25 kg.

Why does glued vinyl use so little adhesive compared with ceramic? Because it is applied in a much thinner layer (thin spread), very different from the thickness of a ceramic tile adhesive.

When is the glued system worthwhile compared with floating in vinyl? In heavy-traffic areas or with wheeled traffic (offices, shops), where the greater stability of glued makes up for being more laborious to remove in future.

Conclusion

Choosing C1 or C2 according to the real tile format —not out of habit or to save money— is what prevents paving from starting to sound hollow months after installation. In vinyl, deciding between glued and floating according to the real use of the room determines both stability and how easy it is to replace in future.