There are various types of ties used when securing reinforcing bars. Much of the tying is done on flat, horizontal formwork such as floor slabs, and many backaches can be saved if one learns to bend and tie stiff legged instead of squatting. Several of the most common types of ties are illustrated and described in the article. A snap or single tie is normally used in flat horizontal work to secure the reinforcing bars in position against displacement due to work done by other trades and by concrete placing. This is a very simple tie, an is wrapped once around the two crossing bars in a diagonal manner with two ends on top. The ends are then twisted together with a pair of pliers until they are very tight against the bars. The wrap or snap tie is normally used when typing wall reinforcement, holding the bars securely in position so that the horizontal bars do not shift during the construction progress or concreting. The tie is made by wrapping the wire 1 and one-half times around the vertical bar, and then diagonally around the intersecting horizontal bar, completing the tie in the same manner as a snap tie. A saddle tie is more complicated than the two just described but is favored in certain localities. It is used particularly for tying of footings or other mats to hold hooked ends of bars in position; also is used for securing columns ties to vertical bars. The wires pass halfway around one of the bars on each side of the crossing bar, then are brought squarely around the crossing bar, then up and around the first bar where it is twisted. The wrap tie is similar to the saddle tie except that the wire is wrapped one and one-half times around the first bar. This type is sometimes used to secure heavy mats that are lifted by crane and for securing column ties to verticals where there is a tendency for considerable strain on the ties. A figure eight tie is occasionally used in walls, instead of the wall tie but it is not particularly recommended because of the time required to make the tie. The proper tying of bars essential in order to maintain their position during work done by other trades and during concrete placing. However, it is not necessary to tie bars at every intersection., tying adds nothing to the strength of the finished structure. In most cases, a tie at every 4th or 5th intersection is all that is necessary. Ends of finished ties must be kept clear of the face of the concrete.