At the time set for hearing by the board of condemnation in section 2.26.030 of this chapter, the mayor shall meet and hear the matter and receive evidence. The mayor shall find and determine what removal, repair or alteration is necessary or whether partial or total destruction of such building or structure, or any part thereof is required in order that the same shall not constitute a nuisance. The mayor shall also determine and find the length of time necessary to complete any such repairs, alterations, removal or destruction; such time to begin to run upon the service of findings of the mayor which shall be by certified mail addressed to the owner of the property at the owner's last known address. (Prior code § 6-2-3)