What is the typical minimum end bearing for a joist on masonry?

The typical minimum end bearing for a joist on masonry is 50 mm. This amount of bearing is crucial for ensuring the structural integrity and stability of the joists. With at least 50 mm of end bearing, there is adequate support to prevent potential failure or deflection of the flooring system. This measurement helps distribute the load effectively across the masonry and minimizes risks associated with settling or shifting over time.

The other options do not reflect standard practices. A bearing smaller than 50 mm may not provide sufficient support, leading to structural issues. While 89 mm and 100 mm are larger than necessary, and while these could be acceptable in certain situations depending on design requirements and local codes, they are generally beyond the typical minimum required. Therefore, adhering to the 50 mm standard is both effective for performance and commonly accepted in the construction industry.