We have a customer with exterior flagstone. In one area water tends
to gather and puddle causing lots of efflorescence and molds to grow
as it is also under lots of mature trees where the sun will not see it
much. It looks as if the builder graded the yard in such a way that
all the rain water and sprinkler water gathers in that same spot on
the flagstone. Do you have any thoughts or recommendations that might
help get the water to another location?