69 SECTION 9. CONTRACTS 9.1. 9.1.1. 9.2. Types of Contracts For contracts that stipulate a lump sum price, the work that is required to be performed by the Fabricator and the Erector shall be completely defined in the Contract Documents. For contracts that stipulate a price per pound, the scope of work that is required to be performed by the Fabricator and the Erector, the type of materials, the character of fabrication and the conditions of erection shall be based upon the Contract Documents, which shall be representative of the work to be performed. For contracts that stipulate a price per item, the work that is required to be performed by the Fabricator and the Erector shall be based upon the quantity and the character of the items that are described in the Contract Documents. For contracts that stipulate unit prices for various categories of Structural Steel, the scope of work that is required to be performed by the Fabricator and the Erector shall be based upon the quantity, character and complexity of the items in each category as described in the Contract Documents, and shall also be representative of the work to be performed in each category. Calculation of Weights Unless otherwise specified in the contract, for contracts stipulating a price per pound for fabricated Structural Steel that is delivered and/or erected, the quantities of materials for payment shall be determined by the calculation of the gross weight of materials as shown in the Shop Drawings. Commentary: The standard procedure for calculation of weights that is described in this Code meets the need for a universally acceptable system for defining “pay weights” in contracts based upon the weight of deliv- ered and/or erected materials. These procedures permits the Owner Code of Standard Practice for Steel Buildings and Bridges, March 7, 2000 AMERICAN INSTITUTE OF STEEL CONSTRUCTION70 9.2.2. to easily and accurately evaluate price-per-pound proposals from potential suppliers and enables all parties to a contract to have a clear and common understanding of the basis for payment. The procedure in this Code affords a simple, readily under- stood method of calculation that will produce pay weights that are consistent throughout the industry and that may be easily verified by the Owner, While this procedure does not produce actual weights, it can be used by purchasers and suppliers to define a widely accepted basis for bidding and contracting for Structural Steel. However, any other system can be used as the basis for a con- tractual agreement. When other systems are used, both the supplier and the purchaser should clearly understand how the alternative procedure is handled. . The unit weight of steel shall be taken as 490 Ib/ft3 [7 850 kg/m]. The unit weight of other materials shall be in accordance with the manufacturer's published data for the specific product. The weights of Standard Structural Shapes, plates and bars shall be calculated on the basis of Shop Drawings that show the actual quantities and dimensions of material to be fabricated, as follows: (a) The weights of all Standard Structural Shapes shall be calculat- ed using the nominal weight per ft [mass per m] and the detailed overall length. (b) The weights of plates and bars shall be calculated using the detailed overall rectangular dimensions. (©) When parts can be economically cut in multiples from material of larger dimensions, the weight shall be calculated on the basis of the theoretical rectangular dimensions of the material from which the parts are cut. (d) When parts are cut from Standard Structural Shapes, leaving a non-standard section that is not useable on the same contract, the weight shall be calculated using the nominal weight per ft [mass per m] and the detailed overall length of the Standard Structural Shapes from which the parts are cut. (ec) Deductions shall not be made for material that is removed for cuts, copes, clips, blocks, drilling, punching, boring, slot milling, planing or weld joint preparation. Code of Standard Practice for Steel Buildings and Bridges, March 7, 2000 AMERICAN INSTITUTE OF STEEL CONSTRUCTION9.3. 9.4. 71 . The items for which weights are shown in tables in the AISC Manual of Steel Construction shall be calculated on the basis of the tabulated weights shown therein. . The weights of items that are not shown in tables in the AISC Manual of Steel Construction shall be taken from the manufactur- er’s catalog and the manufacturer’s shipping weight shall be used. Commentary: Many items that are weighed for payment purposes are not tabulat- ed with weights in the AISC Manual of Steel Construction. These include, but are not limited to, Anchor Rods, clevises, turnbuckles, sleeve nuts, recessed-pin nuts, cotter pins and similar devices. . The weights of shop or field weld metal and protective coatings shall not be included in the calculated weight for the purposes of payment. Revisions to the Contract Documents Revisions to the Contract Documents shall be confirmed by change order or extra work order. Unless otherwise noted, the issuance of a revision to the Contract Documents shall constitute authorization by the Owner that the revision is Released for Construction. The contract price and schedule shall be adjusted in accordance with Sections 9.4 and 9.5. Contract Price Adjustment When the scope of work and responsibilities of the Fabricator and the Erector are changed from those previously established in the Contract Documents, an appropriate modification of the contract price shall be made. In computing the contract price adjustment, the Fabricator and the Erector shall consider the quantity of work that is added or deleted, the modifications in the character of the work and the timeliness of the change with respect to the status of mate- rial ordering, detailing, fabrication and erection operations. Code of Standard Practice for Steel Buildings and Bridges, March 7, 2000 AMERICAN INSTITUTE OF STEEL CONSTRUCTION