This is one of the scary parts about buying an as-is foreclosure. You should definetely hire a certified mold inspector to take a look and assess the extent of the damage. Don't look for a general home inspector, but an actual mold inspector. Sometimes they can be both. You should be able to arrange for an inspection even if you aren't in conract yet. Ask your agent about it. If the mold has entered the house/basement then there could be much more damage than meets the eye. There are several different types of mold, and many are very bad for your health. Also, go ahead and try to secure an insurance quote on the property. If there is an extensive history of water damage and possibly several past insurance claims due to this, then you may have trouble insuring the property, and therefor securing your financing. Your mortgage company will definetely have to document insurance on the home before they give final approval. Good luck!