Essentials to the Owner. The owner, on his part, is under the economic necessity of obtain ing most or all of the following valuable things as a result of his contract: (a) Quantity of work.
(b) Quality of work.
(c) Time of completion.
(d) Special privileges.
(a) Quantity of Work. In a construction contract, when the work has been completed, the owner is to have something that he did not have before; and the amount of what he is to have, secured for him by the contract, should be most carefully understood before the work is commenced. If the structure is to be built of concrete, the owner must receive enough cement, enough sand, enough stone, enough steel, and enough of all the various materials that are going into the structure, to justify him in his expenditure, or it will not be a financial success. Moreover, he must have the quantity that his original understanding with the con tractor guarantees. His architect, for this pur pose, lays out elaborate plans showing in detail a very large portion of the finished work; and the specifications, which accompany the plans, and which are regularly made a part of the contract, are intended to insure, among other things, that there shall be no skimping in work below the understood and agreed-upon standard. In actual fact, as the practice runs to-day, it is not at all easy to guard against errors in and violations of the original arrangement in this regard. Take the simple case of cement, for example. The architect may specify that the concrete shall be made of a 1:3:5 mixture, meaning one part of cement, three of sand, five of stone. If the ma terials are specified as of these parts by weight, it will be difficult to enforce the rule with exact ness, because of the ordinary difficulty of weighing upon the ground, and also because of the fact that these materials, except stone, weigh considerably more when they are wet than when they are dry. When, on the other hand—as is usually the case—the materials are specified by measure, there is room for mis understanding, because the space which a given amount of sand or cement will take up depends to a considerable extent upon the degree to which it is packed. A packed barrel of Portland
cement contains about 3.8 cubic feet, more or less, of cement; but, if sifted, the dry cement in one barrel may easily amount to considerably over 4 cubic feet; and, depending upon the way in which such a term of the specification is inter preted, will the owner get more or less material for his money.
Sometimes the contract may provide that the mixture is at the discretion of the contractor, and that the owner is satisfied if the finished concrete will pass certain tests, in which case there is less room for misunderstanding. Such practice, however, has not yet become general in the United States.
A contract for structural steel work may be for a lump sum or for so many cents per pound. If on the lump sum basis, the owner is inter ested in receiving the number of pounds of material as covered by the plans. Now, it hap pens that the steel mills cannot roll the sections with absolute uniformity, and there is sometimes a difference of several per cent between the esti mated standard handbook weight per foot of steel shapes and the actual weight of those steel shapes when shipped. The difference is caused by the variations in the adjustment of the rolls in which the material is made. In a case of this kind, it is generally conceded that varia tions in the estimated weight amounting to per cent are permissible, except in the case of such material as sheared plates more than 100 inches wide, in which case 5 per cent variation from the theoretical weight is ordinarily allowed. In a large piece of steel work, some of the ma terial will be over-weight and some under weight, so that in the long run the errors will tend in some degree to balance each other.
In the case of a brick building where the contract is upon the unit-price basis, there is likely to be some discussion as to what allow ance must be made for the spaces of doors, win dows, and other openings; and it is essential, in a contract of this kind, to specify carefully how the number of units of performance in the work shall be estimated or determined.