Stucco will crack when the imposed tensile stresses exceed the tensile strength of the stucco and lath combination. Tensile stresses are caused primarily by shrinkage of the stucco during the curing process. Shrinkage of stucco has been studied over the years and is well documented.
It is impossible to eliminate all stucco cracking. Hopefully all of these points are helpful and lead to improved stucco wall performance and greater satisfaction to architects, building owners and the lath and plaster trade.
Hence the need to follow good work practices to minimize the stresses on the stucco and minimize cracking potential. Here are some of those fundamental factors: