I am having an addition put on my house. The block wall has brick veneer to match the exisitng brick band around the base of the house. The mortar joints seem too large, 3/4" and after a few days I was able to pull up the brick on the corners by hand. No adhesion of the mortar to the brick. The courses under the immediate corner is solid or at least I can not pull up by hand. Is the mortar mix bad or has it not cured yet? Is there a maximum joint size?