Lead pipe is found in many older homes, as it was the most common pipe material used prior to the 1950s. Tying into or updating the lead pipe with plastic or poly pipe requires the use of a rubber coupling which are available in several sizes and shapes to accomodate different pipe diameters. Remove any old piping and hang the new poly pipe prior to making the connection.
Determine the size of rubber coupling required. Measure the diameter of the existing lead pipe and the diamter of the poly pipe. Purchase a coupler that will fit over the lead pipe and the poly pipe.
Push the end of the rubber coupler snugly over the end of the lead pipe.
Insert the poly pipe into the opposite end of the coupler.
Tighten the hose clamps on both sides of the coupler with a flat head screwdriver.