If the supports are spaced more than 300 mm apart, what is the advised minimum thickness for ceramic tile underlayment?

The advised minimum thickness for ceramic tile underlayment, when supports are spaced more than 300 mm apart, is 12 mm. This thickness provides adequate structural support and resistance to bending forces that may be encountered. When the spacing between supports increases, the likelihood of deflection in the subfloor also increases. A thicker underlayment helps to minimize this deflection, ensuring that the ceramic tiles are laid on a stable, supportive surface, which is crucial for preventing cracking and maintaining the integrity of the tile installation.

In certain scenarios, thinner materials might not offer the necessary support, leading to premature failure of the tile installation under varying loads or stress. Therefore, adhering to the minimum thickness guidelines helps achieve a durable and long-lasting floor.