In some specifications there is a clause requiring the contractor to guarantee the installation against defects in workmanship and material for a certain period of time, usually from one to two years, after the completion of the contract. The careful estimator for a responsible contractor will not brush this condition lightly aside without considering it, but will give the item the proper charge in the cost column. Outside of the output of a very few manufacturers no goods entering into a plumbing installation are guaranteed, and of the few makes of fixtures which are, the guarantee covers only the replacing of the defective fixtures with new ones, but does not allow for the labor and materials necessary to make the change.

It will be seen, therefore, that when the plumber is called upon to guarantee work done under his contract he is called upon to guarantee materials that the manufacturer will not take that chance on, and if he is to stand sponser for other people's wares he should be paid liberally for the risk he runs. The contractor has no choice in the selection of his goods, which are specified by the architect, and having no alternative in the matter when he puts in the goods called for his work should end. If the goods themselves are inferior, so long as they are what are specified, no blame should attach to the contractor. He follows directions, and, having done so, if he is to be held responsible for the poor quality of the work turned out by some manufacturer he is entitled to payment for the responsibility.

The estimator should keep himself well posted as to the quality of the several goods on the market, and, in proportion as the goods called for are reliable or not, he should add to the sum charged under the item of "guarantee."

Where the contractor acts as guarantor, even under the most favorable circumstances when the goods are guaranteed, he is still out of pocket, for he must replace the defective goods at his own cost. Where the goods are not guaranteed by the manufacturer he has to stand not only the cost of replacing the defective goods but also the purchase of new fixtures to replace the defective ones.

Some specifications require that not only shall the contractor's work be guaranteed against defects in material and workmanship, but, furthermore, any damage caused to the building, finishings or furnishings by a defect in material or workmanship shall be made good by the contractor. This places upon him the additional burden of insuring the building against damage, and in such cases an extra allowance must be made to cover possible damage that might occur. The estimator should remember in this respect that it is possible, and not probable, damages he must allow for, so as to be on the safe side.