Residential Property Management/Mold in shower/bathroom
Have had a 2BR/1 bath rental house for close to 15 years. Current tenants (2 adults, 2 teenagers) have been there for 4 years. About 2 years ago the lady complained of mold in the tub/shower area. Never had been an issue before this family but I replace all the caulking in the tub shower area. She called last week and mention that there is mold again in the same areas. I went and looked at it and yes there is mold. I asked her if she is running the bath fan and she said yes. What I think is happening is they all take showers in the morning, shut the fan off and leave for school/work so the moisture just sits in the tub area and starts to mold. See stated matter of factually that "this is starting to be a health issue" which I take she may call the rental inspector if it happens again which it probably will. I will be replacing the caulk again this week but what should I do if she calls the inspector for mold that is in fact being caused by the tenant?
Much will depend on the source and the extent of the problem. If there are no water leaks (or prior water leaks that were allowed to persist and grow into a mold issue), then the cause is probably what you suggested in your question. Showers that are not adequately ventilated often will result in mold/mildew along grout lines. In that situation, it can usually be easily cleaned with a product designed for that purpose. You probably don't need to remove/replace the grout unless it is in bad condition, although taking that step may put your tenant more at ease. Yes, you will need to educate the tenant on the importance of running the exhaust fan (or opening a window) when showering, and for a time after. One trick would be to tie the light and fan together so that they both run concurrent every time the bathroom light is turned on.
There's nothing to stop the tenant from calling an inspector, but if the problem is as minimal as I'm envisioning based on your description, you shouldn't encounter any serious problems. You could also call in a mold expert to do testing (which can be expensive), but again, it depends on the extent of the problem and its source.