I. Except for city blocks, staking out the building is generally left to the contractor, but the superintendent should see that it is carefully done, and very often he is expected or called upon to assist in running the lines. The principal corners of the building should first be carefully located by small stakes driven into the ground with a nail or tack marking the exact intersection of the lines. The lines should then be marked on batter boards, put up as shown in Fig. 1. Three large stakes (2x4 or 4x4) are firmly driven or set in the ground at each corner, of the building and from six to ten feet from the line of the building, according to the nature of the ground, and fence boards nailed horizontally from the corner post to each of the other two posts. These boards should be long enough so that both the inside and outside lines of the foundation walls may be marked on them. The stakes should also be braced from the bottom of the corner stake to the top of the others. This makes a firm support for the lines and one that need not be moved until the walls are up for the first floor. These boards have the great advantage over single stakes that they are more permanent, and that all projections of the walls, such as footings, basement wall and first story wall, can readily be marked on them. It is a good idea to indicate the ashlar line by a saw mark, the basement line by a nail and the footings by a notch, then no mistake can be made by the workmen. If the top of all the horizontal boards are kept on a level it assists a great deal in getting levels for the excavating, etc.

Foundations On Firm Soils Staking Out The Building 1001

Fig. 1.

The superintendent will be expected to furnish the contractor with a bench mark, from which he can get the level for his footings, floor joist, etc. This mark should be put on some permanent object, where it can be referred to after the first floor joists are on. In giving such data to the contractor the superintendent must be very careful, as he can be held responsible for any loss resulting from errors which he may make. It is a very safe and good rule to give as few lines, data or measurements as possible to contractors, requiring them to lay out all the work themselves and to be alone responsible for the accuracy of their work.

2. Diagonals

After the batter boards are in place and properly marked, the superintendent should require the contractor or his foreman to stretch the main lines of the building, and the superintendent should carefully measure the diagonals, as A B and C D, Fig 1, with a steel tape; if they are not exactly of the same length the lines are not at right angles with each other and should be squared until the diagonals are of equal length.

On fairly level ground a building may be accurately laid out by means of a steel tape, using multiples of 3, 4 and 5 for the sides and hypothenuse of a right angle triangle. The larger the triangle the more accurate will be the work.

3. For buildings which are built out to the street line the lines of the lot should be given by a surveyor employed by the owner, and should be fixed by long iron pins driven into the street, or by lines cut on the curbstone across the street. In building close to the party lines of a lot it is, of course, of great importance that the building does not encroach upon the adjacent lot, and to prevent this it is always well to set back one inch from the line, thus allowing for any irregularities or projections in the wall.