Hardness is the primary characteristic of Portland Cement Plaster. Without it, the walls will not last long. Incidental impact will deteriorate the wall prematurely and wind driven rain will wear it down. Weed eater string can open up uncured walls. This is why it’s important that the wall be cured. It’s also why one-coat stucco must be allowed to set and cure.
Why was I easily able to drive my truck key into this wall? Sometimes it’s because the sand/cement ratio is so out of compliance that there is not enough cement to bind the sand together.
In the case of the wall above with my knife buried in it, one-coat stucco flash dried because the surface of the material was sand floated. Afternoon winds dried out the walls before the cement set, no moisture was added back in, and the walls were painted with a good paint coat.
I got involved when the Home Builder called because broom handles were punching holes in the walls, ladders put against the walls were punching through the plaster, and when I tested the walls with a buck knife…. well, you can see the result.
I confirmed the inadequacy of the walls in front of 4 representatives of the Insurer by punching a hole in the plaster with my knuckle. The cost of not confirming the hardness of the wall prior to paint? $8 million dollars.
If you have questions about this condition or other situations, call or email: