Grout Stop Installation Information
Grout Stop Benefits
The purpose of grout stop installation in a masonry wall is to create a “bond beam”. A “bond beam” is a
horizontally reinforced element in a masonry wall that provides resistance to shear loads and also helps
distribute lateral loads throughout the wall section. Reinforcement is placed in special bond-beam units that
have reduced-height cross webs and grouted solid. Bond beams are typically one course tall; grout is
prevented from filling cells below by placing a mesh-type grout stop material in the bed joint underneath the
bond beam. Bond beams are usually seen at the top of foundation walls, tops of walls, and at each floor
diaphragm connection. Intermediate bond beams are often required in higher seismic design categories.
Grout Stop and Bond Beam Blocks
Bond beam blocks are concrete masonry units that are similar to standard concrete blocks, except that the
webs are cut to remove the upper portion. In many cases, the block units are provided with knock out sections
that are removed when the units are used in the bond beam. The notch in the top of the webs creates a space
into which the horizontal reinforcing is placed in a reinforced masonry wall. The vertical reinforcing extends
through the cells in the bond beam unit. A wire mesh or fabric is placed in the bed joint just below the bond
beam unit at any of the cells that do not contain vertical reinforcing as the walls are erected. This mesh
prevents the grout from flowing down the vertical cell space so the horizontal bond beam can be filled without
filling all the vertical cells.
Construction Concerns
The intersection of a bond beam with vertically reinforced cells can be very congested, with multiple bars in
each direction. Minimize the amount of bond beam steel to improve grout flow and permit proper grout
consolidation. Use L-shaped corner bars, lapped with the bond beam steel, to provide continuity around
building corners.
What to Do at Expansion and Control Joints
For most conditions it is best to cut bond beam reinforcement at expansion joints and control joints. The
exception to this rule is at floor diaphragms, where the bond beam may be acting as the diaphragm chord and
must be continuous down the wall. It is possible to detail a slip connection around bond beam reinforcement,
but normally, lateral continuity across movement joints is not required for structural performance.
Resources
masonrysystems.org
masonryconstruction.com
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