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Re: Masonry Expansion Joints

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If you are talking about "concrete masonry units", I generally provide 
"control joints" rather than "expansion joints".  (The main problem with CMU 
is shrinkage, not expansion.  But with clay brick, expansion is a concern.) 
I 
use a CMU lintel beam and extend it with 8-inches (min) bearing each end. 
If 
I'm using a control joint, I offset the control joint above the opening by
the 
width of the lintel bearing length and provide an unbonded sliding surface
for 
the lintel bearing on that side.  I use a masonry control joint detail which 
permits lateral load transfer between units but doesn't prevent shrinkage.   
 
Regarding spacing of CMU control joints, I use a larger spacing if I am 
providing horizontal reinforcement and moisture-controlled units.  With 
prefabricated joint reinforcement at 16-inches on center, NCMA (TEK Note 53) 
recommends a maximum panel length/height ratio of 3 with an upper limit of 
50-ft (vs a ratio of 2 and a limit of 40-ft for unreinforced).  A 
well-reinforced seismic wall with uniformly spaced bond beams should be even 
better. 
 
Any bond beam which must transmit structural loads (as opposed to being only 
for crack control or local stresses) should be continuous thru control
joints 
(e.g., roof chords or bond beams carrying lateral loads).