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control joints in grouted cmu walls

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It depends on where you are located.  I would not consider using 
control/expansion joints any further apart than 15' to 20' here in southern 
Arizona.  (When I was still in school, we would pace off distances between 
cracks in masonry walls --- and it would come out to be about 15' to 20'.  
That's where Mother Nature wants them, and that is where I will put them!)

There was a fairly recent (2 - 5 years ago) technote from BIA or from NCMA 
that placed the joints much closer together than previous recommendations had.

I think that putting mortar in a control joint is unwise and I specify that 
caulking or a wide flange expansion joint material as a better choice.  
Owners tend to be unhappy if they see mortar cracking, even if it is supposed 
to crack.

A. Roger Turk, P.E.(Structural)
Tucson, Arizona

Paul Franceschi wrote:

>>what are the requirements for control joint spacing in a grouted cmu wall?  
I found general typical details in the Concrete Masonry Asociation handbook 
(recommend approximately 50' - 60' spacing), but no reference in code.  What 
are the issues with leaving the joints out all together? I have a single 
story Zone 4 "L" shaped building, 50' and 60' long on the end walls, 
longitudinal wall max length of 120', and 2 sections at the L side are 30' 
and 90'.  What is a common joint filling material if block is left exposed to 
view ? (Using split face block)<<

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