Where work to be performed, excluding regular maintenance work, which would otherwise be subject to the State Contract Act, does not lend itself to the preparation of plans and specifications to enable bids to be taken on a lump sum or unit basis, and the director so finds, the department may perform such work by the use of rented tools or equipment, either with operators furnished or unoperated. Contracts for such work may include provision for equipment rental and in addition the furnishing of labor and materials necessary to accomplish the work. Such contracts shall not be subject to the State Contract Act, but shall be subject to all of the provisions of Section

136.5 of the Streets and Highways Code, and of Article 2, Chapter 1, Part 7, Division 2 (commencing at Section 1770) of the Labor Code.