For roof slopes of 3:12 and over in clay and concrete roof tile installation, the underlayment must be what minimum width?

In the context of clay and concrete roof tile installation, when dealing with roof slopes of 3:12 and steeper, the minimum width for the underlayment is specified to be 11 inches. This requirement ensures that there is sufficient coverage to protect against water infiltration, particularly at vulnerable areas such as seams and laps where tiles can be susceptible to leakage.

Using a minimum of 11 inches allows for adequate overlap between successive rows of tiles and helps to effectively shed water away from the roof structure. Adequate underlayment width is crucial in maintaining the longevity of the roofing system, as it aids in providing a secondary barrier against moisture, which can lead to severe damage if not properly protected.

Therefore, specifying an underlayment width of less than 11 inches would not provide enough coverage to adequately guard against potential leaks, which underscores the importance of compliance with this requirement in building codes and industry standards for tiled roofing installations.