Properly installed stucco can last many decades; at least 40-50 years under normal conditions. This long life can be shortened dramatically by certain influences.
Typically, the influence with the greatest impact is moisture intrusion. Of course stucco is designed as a “building envelope” which, by its nature, protects against the rain and other sources of moisture from the outside (like normal overspray from sprinkler systems). In these scenarios, the stucco immediately sheds the bulk of the water, and only minor amounts are absorbed, and that which is absorbed is typically dried out by the sun and breeze – thereby removing the possibility of damage to the stucco system. Unusual and early deterioration of stucco systems almost always takes place when water finds its way inside the building envelope. Water that enters the system and remains there will be unable to dry out quickly can do serious damage to all components of the stucco system, including wood framing, metal components like lath, and of course the stucco itself.
Properly installed stucco DOES NOT allow liquid water to permeate its thickness – except for areas with extreme cracking that allows water to pass through the cracks (typical stucco cracking does provide a path for water).
Ask your San Diego stucco company how they can fix this stucco problem.