New Cast Iron Plumbing

Industrial lofts are commercial buildings and have different plumbing and electrical standards than residential buildings. In a house, the drain pipes are often black plastic (ABS) that can be cut with a hacksaw and connected with pipe cement. In a commercial building, however, the California building code requires cast iron drain pipes.

Since we are plumbing a new bathroom and kitchen on the ground floor of our loft, we need to use cast iron, but we lack the appropriate tools and experience. So we sought the help of an experienced commercial plumber.

How is cast iron cut to length? Amazingly, it is snapped with a chain! The simple and clever tool used for this purpose is called a "snap cutter." The pipe is marked where it needs to be cut, the chain is wrapped around the pipe with its special raised links sitting on the mark and the chain is then tightened with a ratcheting action. After a few cranks, the pipe suddenly snaps in a clean break, shooting a foot or two across the floor.

Pipe Snap Cutter

To connect two lengths of cast iron together, no pipe cement is used. Rather, a rubber coupler sleeve with a metal strap jacket is use to connect the two ends together and seal them shut against leaks.

Pipe Coupler

Since we are retrofitting the cast iron plumbing, we are surface mounting the pipes and need a system to hold the pipes in place against the wall to maintain the proper drainage slope and eliminate movement. We are using Uni-struts - load-bearing channels that attach to the metal studs in the wall with screws. Our Uni-struts were cut in one foot lengths to carry several pipes at once. In our case, they carry the copper water lines that bring water in, and the cast iron that drains graywater out. The copper pipes are wrapped in a felt sleeve before they are attached to the Uni-strut because two dissimilar metals will corrode when left in contact. The felt protects the copper from the galvanized steel. The cast iron and Uni-strut are both iron-based, so they don't need a felt buffer.

Uni-Strut

We now have over 50 feet of new pipe running along one side of the loft to service the bathroom and kitchen. We could paint it to match the walls, but we are planning to cover it with a long run of cabinets that will serve as a place to store office supplies as well as display artwork.