How to connect the new pipes to the old ones.
Synopsis: A guide to techniques and materials that allow new plumbing lines to be connected to old ones, not necessarily of the same material. It would be especially helpful for anyone working around old houses, where some worn-out plumbing invariably needs replacement.
At some time in just about every remodeling job, new plumbing has to be joined with the old. You might be replacing a corroded supply line, plumbing a bathroom addition or relocating the lines for a remodeled kitchen. Most plumbers agree that remodel plumbing is far different from doing new work. Sometimes it’s as simple as connecting new fixtures to the old lines, but often it’s an excruciating exercise in Murphy’s Law. The old-pipe diameters aren’t the same as the new ones, the pipes aren’t made of the same materials and your workspace is ideal for a dwarf contortionist. Fortunately, these are common problems, and those who have been down this road before have figured out some good solutions. This article is a stew of advice, products and tools that can make your remodel plumbing connections work out for the best.
Checking out the old system
Before hooking into the old system, you have to look at what’s really there. Check for obvious leaks and look for traces of rust or corrosion on the outside of galvanized fittings. Reduced water flow and rusty tap water are signs that the water-supply system may be ready to rupture. A rust-weakened pipe that might otherwise last for years will often break apart with the first torque of the pipe wrench.
Restricted flow can be caused not only by rust buildup but also by non-corrosive mineral deposits. But in either case, when you start knocking around the old pipes you will often dislodge enough crud to…