We have white garage doors (double car garage) and they have mold on them.

We have washed them with soap and water and even repainted them and the mold still comes back.

Is there a trick to getting the mold off and preventing it from coming back?

Thanks so much

~Heather

2 questions Heather to Help clarify things
1) Are they Wood or Metal?
2) Which direction do they face? Towards the Sun of a Day? or Away from the Sun ? (in the shade)
And is it a Black or Greenish? color(the Mold)

they are metal

they face north

the mold is not really black but more of a black with green tinge

and we live at the beach

Thank you so much, Mike.

~Heather

Ok the reason for the spots appearing could be
related to an overhanging bush or tree shedding pollen?
NO tree or plant and you live by the seaside rules out damp But the sea air is corrosive..
So what to do?
If this is rising from the foot of the Door.
then paint a foot high barrier strip of the same color paint from the bottom up with "Anti Fungal" paint(after cleaning) there is also Mold inhibitor paint. Both I expect will be pricey? But I think (not checked) a clear coating version of the same products may be for sale?
I think your Local Diy superstore will have these in stock and have some leaflets on how to apply
I expect a Medium sized tin will be adequate for this Job

Thanks for the info. There's no over hanging trees near there,althoughwe have alot of trees on the property.I don't think we tried anti fungal paint,we just cleaned,the painted. Again, thank you so much,I will try your suggestions.Have a great day!

Heather.

Hey Heather - The maintenance guy at the Inn I used to work at (with the same conditions present as what you have) used a 4-1 solution of bleach and water. He'd apply it, scrub, and re-do if needed. Then rinse well with just water.