A gate valve for a property usually has to be closed if plumbing repairs or maintenance are needed inside the building. In some instances, particularly if the main control valve is a gate type valve, the valve may not close completely. In many cases a gate valve repair or replacement may be needed. But many times other remedies are available.
A gate valve not closing completely is typically due to sediment that has built up inside the body of the valve. The sediment becomes lodged between the gate that lowers, and the inside of the valve body itself. Ball type valves do not suffer from this problem, as they operate on a different principal than a gate that raises and lowers inside of the valve body .
The typical reaction when a gate valve will not close fully is to exert addition force on the handle. Using force to close a valve is absolutely the wrong response. Brute force can cause permanent damage to the valve and a loss of water supply to the building.