[LazyPup]

Although it is almost never used today, originally cast iron pipe DWV pipe and Vitreous Clay sewer pipe was what is known as "Hub & Spigot pipe". Each section of pipe or fittings have a female hub on the input (upstream end) and the discharge (downstream) end it has a "male" raw pipe diameter.

Traditionally they would begin laying the pipe at the septic tank or municipal sewer location and work backwards toward the structure. The male "spigot end" of each section of pipe is inserted into the female "hub" of then the space between the exterior wall of the male pipe and the interior wall of the female hub was packed half full of a fibrous hemp material called "oakum".which looks like frayed rope that has been saturated in a tar like substance. When the oakum was firmly packed in place the joint was then capped off with molten lead.

The plumbing codes no longer permit the use of lead to make pipe joints.

For new construction, when cast iron pipe is specified we use a type of cast iron pipe known as "No-Hub pipe" No hub pipe is straight cast iron pipe with a raw pipe end (spigot) one each end and it is connected by means of "Mission Band" clamps. Mission band clamps are simply a neoprene sleeve with an outer metal sleeve surrounding the neoprene sleeve, and held in place by screw down spring clamps similar to the radiator hose clamps used in the automotive trade.

Repairing your sewer line is a fairly easy job. The first task is to remove the defective section of pipe. Fortunately cast iron pipe is very brittle and can easily be broken out by holding a heavy hammer tight against the pipe wall on one side and hitting the opposite side of the pipe with a second heavy hammer. (i use two 3lb hand sledge hammers). Careful here, cast iron pipe is brittle and shards may fly off as it breaks. i strongly advise you to wear good quality leather work gloves and goggles when shatter cast iron pipe out.

One you have the defective section broken out you will have a raw spigot end on the cast iron pipe and there should be a cast hub in the wall of the septic tank. (see illustration).

Measure the distance from the bottom of the hub in the septic tank wall to the end of the cast iron pipe and cut a length of schedule 40 PVC pipe about 1/2" less.

Insert a "Fernco' neoprene donut into the hub of the septic tank wall and slip a "Fernco CI coupling on one end of the PVC pipe.

Now align your section of PVC with the Fernco coupling on the cast iron pipe end. (upstream end) and insert the opposite end into the donut in the tank wall. You can then align the upstream end of the PVC with the cast iron pipe, slip the Fernco over the joint and tighten the clamps.

NOTE- Be sure you use Schedule 40PVC pipe. PVC pipe is used for both pressure piping and DWV (drain, waste & vent) applications however, PVC pipe used for pressure piping is made in sched. 20, sched,30,sched.40, sched.80 sched.120 and sched.200when used for pressure pipe the pipe has to be certified as suitable under ASTM D-1785.

For DWV (drain, waste and vent) applications all PVC pipe MUST BE schedule 40 and certified under ASTM D-2665. Fortunately all sched.40 pipe is labeled as certified under both ASTM D-1785 & D-2665.