Deterioration generally occurs for 2 reasons, total neglect of the structure over time and the biggest one is improperly installed stucco process. When water is entering behind the plaster excessively the deterioration of the stucco and more and importantly the home occurs at an expedited rate.
Maintenance schedules and the degree of maintanace veries by region, weather conditions as with all materials is a major factor on the amount and the time frame for maintenance. Such things as proper sealants at penetrations, doors, windows, exterior panel box’s and at bond breaks, etc, etc is key, the more water we keep on the surface of the materials the less damage that can occur.
Remember caulk/sealants will do little to nothing to protect your structure when proper flashing details are missing or improperly installed. When we lack proper flashing details we cannot stop water from entering behind the plaster, the more water we allow behind our siding materials the greater chance wee will have of damage that will increase the deterioration of the structure.
Water at all aspects is the kiss of death to a structure not just with stucco, roofs, windows, doors, brick/stone, fiber cement siding, electrical, moisture adjacent to a foundation, etc, etc is all dependent on controlling the water for longevity, failures and for safety.
Other factors can affect the quality of the stucco causing a more rapid deterioration that is been described on other pages and that is the lack of a proper drainage plane, improper window and door installation as well as improper installation of the 3 plaster coats, installation of coats to thin, to thick the lack of cure time between coats and the lack of retarding the curing time with proper hydration of the plaster coats with water all will affect the stucco and can cause issues with cracking letting to much water in behind the cement plaster resulting in deterioration.