WAC 246-359-420
Placing of concrete masonry units (CMU). (1) CMU must be laid in a running bond pattern with the units in
each successive course overlapping the joints in the course
below. At corners the length of the corner unit must alternate
direction on each successive course.
(2) The mortar must be sufficiently plastic and the units
must be placed with sufficient pressure to extrude mortar from
the joint and produce a tight joint. Joint furrowing must not
exceed the thickness of the shell.
(3) Head joints of open-end CMU designed for use as bond
beams that are to be fully grouted need not be mortared.
(4) Surfaces to be in contact with mortar or grout must be
clean and free of deleterious materials.
[Statutory Authority: RCW 70.114A.081. 99-03-065, §
246-359-420, filed 1/18/99, effective 2/18/99.]