Ohio Rev. Code Ann. § 5555.66

In addition to the estimates provided for by section 153.13 of the Revised Code, the county engineer may, under such conditions as he prescribes, allow and pay to a contractor a sum not exceeding ninety per cent of the value of material delivered by such contractor, and safely stored at a railroad station or siding or other point in the vicinity of the work. When such estimate is allowed, the material on which it is allowed shall thereupon become the property of the county, but in case such material is stolen, destroyed, or damaged by casualty before being used, or for any reason becomes unfit for use, the contractor shall replace it at his own expense. A contractor may insure against loss or damage, by fire or otherwise, all materials upon which estimates have been allowed under this or any other section of the Revised Code.