Because most roof flashing is required to extend up the wall a minimum of 4 and some a minimum of 5.
Roof to brick wall connection.
The most common roof to wall intersections involve either a gable roof with its ridge running perpendicular.
Roof trusses attach to a ledger that is on top of a block wall.
Walls that are constructed of concrete block that need to be covered with a roof will require the use of a ledger.
The direct bearing connection is the simplest and most common connection in the home building industry.
The roof flashing is then placed up behind this through the wall z bar flashing on the outside of the vertical blocking backing material.
It takes coordination between the masons and roofers and it requires lots of custom fabricated metal flashing with soldered joints.
A ledger is a horizontal board that is attached to the top of the the wall.
A direct bearing connection is used in instances where the wall below does not continue beyond the roof level i e no parapet.
This detail is used when masonry continues above either as part of the wall or as a parapet the connection location and eccentricity is to be minimized.
Most simply use a nominal 6 piece of lumber.
Pocket connection a pocket connection consists of framing the floor or roof system into a void in the masonry wall.
A ledger board is a horizontal member that supports the ends of joists or rafters where they meet a.