Block wetness Q: Is there a point when block is too wet to be put in a wall?
A: Currently, there are no accepted industry standards for determining “how wet is too wet.” But let’s use plain old common sense.
To create a good bond between concrete masonry units and mortar, units have to have enough suction to draw in the mortar’s moisture. Too much suction leaves too little water in the joint to develop strength; too little suction means not enough strength. Too much moisture may create shrinkage cracks; too little means dry outs.
Then there’s weather, one of the most critical, variable, and uncontrollable factors in a construction project. Complicated? Yes!
This is where skilled craftworkers come in. Mortar can be adjusted to accommodate some moisture variations in units or humidity, as can the spread length of the bed joint.
Resource: International Masonry Institute – IMI – www.imiweb.org