Question: If I cannot see the mold is it still a problem?

ANSWER:  YES!  If mold is in your building it is a problem even if you cannot see it.  The main health threat from mold is mold spores.  Mold spores are microscopic.  In other words you cannot see spores.  Once dispersed the spores can be spread through the air.  If mold is in your building you should make every effort to have the mold removed or killed.  Not only is mold a health threat but mold can also cause damage to your building.  Remember mold can "eat" your building materials for a food source.