R502.6

Section R502.6 is titled 'Bearing' and covers the requirements for floor joists bearing on their supporting structural members. The dimension that the end of each joist must bear dependent on the type of material, allowed alternative bearing, options when bearing on masonry or concrete, and wood sill plate on concrete or masonry minimum bearing area is established. The purpose of this section is to prevent structural failure.

The model shows 6 examples of joists bearing on wood, metal, masonry block directly, a wood sill plate on a masonry block, a joist hanger, and a ribbon strip. The joist bears 1-1/2" on the wood top plate and metal I-beam, and 3" on the masonry blocks (both direct contact and with a wood sill plate). The masonry block wood sill plate has a minimum nominal bearing area of 48" to help spread the load across the block. (Note that even though the joist is bearing on a wood sill plate, since the sill plate is transferring load to masonry, the joist must bear onto the wood sill plate 3", not the 1-1/2" allowed for wood bearing.)