My husband and I are considering the purchase of a small house near us for our daughter.  The house has set unoccupied for about a year.  The electricity was off and so the sump pump in the crawl space did not work.  About 16 inches of water sat in a 24-inch crawl space for most of that time.  It has recently been pumped and is relatively dry.  Upon entering the crawlspace we have discovered a black mold on the band joist across the back of the house and out about 8-10” on the floor joist and the underneath side of the subflooring.  The rest of the floor joist and band joist around the house look very good.  These are the steps we are considering with regard to purchasing the house.  We have contacted a professor at a local university. Our intent is for him to do a total sample of the mold to determine the types of mold we are dealing with.  At that point, if we are dealing with a toxic mold, we are not planning on purchasing the house because we would not feel comfortable with our daughter’s safety regardless of the remediation techniques.  If the mold ends up being a “bread mold” variety as expressed by the professor, we intend to remediate the mold ourselves.- Peggy – Indiana 

            Purchase of this house poses a number of issues.  The potential presence of black mold is only one of them and likely only a minor one at that. 

            The apparent black mold that you observed is in most probably not the black toxic mold Stachybotrys chartarum.  If it is growing on wood structural timbers, it is likely to be Cladosporium. 

            The house that you describe has two apparent risk factors for mold infestation.  These include its vacancy with no heating/cooling for a year and the large volume of water that set under for that period of time. 

            The first factor could by itself result in mold growth in the building interior on walls and other surfaces.  The second is of course far worse as it has the potential to cause both water to wick up the walls and to be an enormous humidity-producing reservoir. 

            Many individuals think that if the “toxic mold” is not present, then there is no problem.  Unfortunately that is not the case.  Most if not all mold species can cause allergy and asthma and many can cause sinusitis.  Those are major health concerns in themselves.  Being ill from exposure to molds that are “not toxic” is common and for those who are so, it is a problem particularly if they are your children. 

            The house you describe would likely be very difficult to remediate.  As such, its purchase is not recommended.

January 31, 2003

Indoor Environmental Quality (2000), Thad Godish Ph.D., C.I.H