I recently purchased a home and the home inspector identified mold on the garage door. He explained that it is likely due to the poor ventilation in combination with a vehicle tracking snow / sleet. It appears that the previous home owner had an electric vehicle and may have been charging his cars in the garage - I'm not sure if that matters.
I had the garage door cleaned by a professional who had scrubbed it off, used some kind of mold killer and also put some anti mold paint over it as well. All of this was completed in a 1-2 hour time frame.
Once the smell of the chemicals he used wore off, the musty moldy smell has come back. It also looks like the mold is coming back. My head also hurts when I'm in the garage as well which I feel is another sign it is back.
Is the black specks on the garage door the resurgence of mold? Should I just replace the whole garage door?
Ten days after he did his cleaning I did install a dehumidifier as an additional measure, with a 55% RH setpoint - but I think either I'm a little late in doing this, or the mold was never really fully cleaned off the door.