19. Curbing to be Completed in Advance.—The setting of all new curbing and guttering and the redressing, resetting or readjustment of all old curbing must be completed at least 100 feet in advance of the construction of the street foundation.
20. Final Cleaning Up.—Immediately after the completion of the work or any consecutive portion of it, the Contractor shall remove from it all unused material, refuse and dirt placed by him on, or in the vicinity of the work, or resulting from its prosecution, and restore the street to a condition as clean as before the work was begun; and the new pavement shall be properly cleaned.
21. Measurements and Computations.—Unless otherwise distinctly provided in the contract and specifications, measurements, computations and payments will be based upon the actual quantities of completed work, customary or conventional methods of measurement and computation to the contrary notwithstanding.
The area of street pavement shall be reckoned in square yards of completed pavement surface, deducting manholes, inlets and other openings in the surface of the pavement having an area of over three (3) square feet. Unless separately paid for under the contract, stone headers and crosswalks will be measured as a part of the pavement surface.
22. The price for the pavement per square yard shall, unless otherwise stated herein, include the preparation of the sub-foundation, the construction of the foundation, the cushion course, and the pavement complete, including all the materials and labor required therefor.
23. Incidental Work at Contractor’s Expense.—All the work to be done by the Contractor for which specific unit prices are not named in the contract, specified and enumerated in Sections 4, 5, 6, 7, 8, 9, 12, 13, 14, 15, 16, 17, 18, 19, and 20, as well as any minor details of work not specifically mentioned in the specifications, but obviously necessary for the proper completion of the work, shall be considered as incidental, and as being a part of and included with the work for which prices are named in the contract. The Contractor will not be entitled to any extra or additional compensation therefor.
24. Extra Work.—The City may require the Contractor to furnish such additional materials and to do such additional work, not provided for in the contract and these specifications, but which may be found necessary or pertinent to the proper prosecution and completion of the work embraced in the contract, at prices to be agreed upon in writing, in advance. But no work other than that included in the contract and these specifications and which is covered by and to be paid for at the prices named in the contract, shall be done by the Contractor except upon a written order from the Engineer, which order shall describe the work to be done and name the compensation agreed upon therefor. In the absence of such written order from the Engineer the Contractor will not be entitled to payment for any such additional or extra work.
In the same manner the city may omit or dispense with items or parts of the work, by previous agreement with the contractor, and a like written order by the engineer. But such additions, omissions or alterations shall not together increase or decrease the aggregate cost of the whole work more than fifteen per cent. (15%). Any changes in the plans, specifications, character of material used or method of doing the work that may increase or decrease the aggregate cost of the work more than fifteen per cent. (15%) may be authorized and validated only by a formal, supplemental contract, regularly executed by all the parties to the original contract.[[4]]
25. Guaranty.[[5]]—The Contractor shall guarantee that all the materials used and all the work done under this contract shall fully comply with the requirements of these specifications, the plans herein before referred to and the instructions of the Engineer. Any defects in the completed work, or any part of it, or any failure of the work to fully perform or endure the service for which it was intended, which, in the opinion of the Engineer, are attributable to the use of materials, skill, or workmanship not in compliance with the said specifications, plans and instructions, within a period of ... years after the date of the certificate of completion and acceptance, shall be regarded as prima facie and conclusive evidence that the Contractor has failed to comply with the said specifications, plans and instructions. And the Contractor shall, at his own expense, at such time and in such manner as the Engineer may direct, repair or take up and reconstruct any such defective work, in full compliance with the original specifications, plans and instructions. And as surety for the performance of this guaranty the Contractor’s bond, required by the contract, shall remain in full force until the expiration of the period of ... years above stipulated in this section.