Many siding contractors simply use bleach and water when dealing with the Lp siding problem or EIFS stucco in the portland vancouver metro area.  Although that may help with some of the mold or fungus, quite simply this just isn’t enough.  Superior Exterior Systems has been using a special industrial strength fungicide for almost 19 years with great success in that we have had ZERO callbacks and that mold has never grown back.  Often times the subwall behind the house wrap of horizontal Lp siding can have traces of  mold spores growing on them so they must be killed even though the actual siding is removed.  Because mold grows in wet dark areas we have always felt a strong conviction that all the mold remidiation is done professionally and thoroughly.  Although this sounds a bit corny, the product we have used for the past 2 decades is found in the salt mines of California and then shipped to us.  Becasue it is so close to the northwest it doesn’t cost much to get it here.  It is then thoroughly mixed and applied on all outside walls successfully killing any mold spores on the subwall or panel siding.  This should always be thoroughly completed before installing any new siding including Hardie Plank, Certanteed Weatherboards, vinyl, stone or replacing Eifs stucco.  For more information on this problem  and to see detailed pictures log into   www.superiorexteriorsystems.com or call  (503) 285-0875 or  (360) 687-8936  for a free no obligation inspection of your siding.  We service the entire Portland Oregon and Vancouver metro area along with the outskirt cities.We hope this helps & thanks for listening.