Basic Remodeling Techniques: Taking Out the Old: Utility Systems

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Once the surface materials have been completely re moved, electrical, plumbing, and heating systems are exposed and accessible. At this point you can evaluate what you’ve got and decide whether to reroute or remove them.

Electrical Wiring

Before you disconnect any wiring, be certain the current is shut off for that particular circuit. Use a voltage tester on all wires to check for power. If the entire circuit is to be removed, the problem is solved simply. First pull the main switch to shut off all power coming into the house. Next disconnect the circuit’s wiring from the service panel. Then remove all switches, outlets, and junction boxes for that circuit. If possible, pull out all wires.

In most cases you need not remove an entire circuit, but only individual outlets and switches. If an outlet to be removed has only one cable coming into the box (which means two wires, one black and one white). it’s wired at the end of the run. Trace the cable back to the nearest box, disconnect it from both boxes, and pull it out. If the outlet box has two incoming cables (four wires), it’s wired in the middle of the run.

If you intend to save any outlets or switches connected on either side, first disconnect and pull out the unneeded cable. Then, if possible, reroute the remaining cables to a new location. This often requires pulling the wiring behind existing wall or floor surfaces with a fish tape. (For information on running electrical cable see discussion below.) If the cable isn’t long enough. pull it out and start over with new unspliced cable. The electrical code demands that all connections be made inside approved outlet or junction boxes, which must be accessible, not hidden behind a finish surface.

If the wiring involved is particularly complex, see Basic Wiring Techniques for additional information. Or call an electrician to sort out the problem. In many instances you can pull the wiring to one side, proceed with the demolition, and have the electrician reroute the system later.


Using a Voltage Tester--A voltage tester has no power of its own but tests for the presence of power in wires or appliances. Use it to be sure the power is off before making repairs, to see if an outlet is hot, or to test for proper grounding. To test for power at an outlet, put probe In each slot.

Plumbing and Heating Pipes

Rerouting plumbing and heating pipes generally re quires removing all or portions of the old system and then running new lines. The existing pipes can’t be pushed or pulled into new locations, so you don’t have the same flexibility as with electrical wiring. Occasionally pieces of the old system can be salvaged and reused. That depends on the type and condition of the material.

Often you can save money by doing the preparatory work yourself. This section describes how to remove various types of pipes, ducts, and heating fixtures you may encounter. Instructions for installing new plumbing lines, however, are beyond the scope of this guide. For that you should consult our guide Basic Plumbing Techniques or call a professional.

Before you remove any water pipes, shut off the sup ply to the branch run. Then locate the appropriate drain valve and remove the water from the pipe.

• Copper pipe. Pipes connected with flare fittings can be disassembled with two wrenches. If the pipe has soldered fittings, cut it with a tube cutter or fine hacksaw blade. You can also disassemble soldered fittings by heating them with a propane torch if there’s enough room. Once the solder melts, pull the fittings apart.

• Plastic pipe. The cement between plastic fittings is so strong that disassembling is impossible, so cut the pipe near the fittings with a hacksaw blade. Long lengths of pipe in good condition can be reused. Fittings must be thrown away.

• Galvanized pipe. Cut galvanized pipe with a hack-saw. Because the pipe is heavier than either copper or plastic, you may need to brace a long length to keep the saw blade from binding. Use pipe wrenches to disassemble unions and other fittings. If the pipe is so corroded that it’s frozen solid, try putting an extra length of pipe over the wrench handle to gain greater leverage. Or expand the fittings by heating with a propane torch. Lubricating oil may also help loosen the fittings.

• Cast iron pipe. If the cast iron is hubless,. you may have enough space to disassemble the clamps and couplings. If there is no access, or the cast iron is joined with lead and oakum, you’ll need to rent a chain pipe cutter. You can also try chipping the lead and pulling out the oakum. although usually there isn’t enough room to pull the pipes apart. Another way to cut cast iron pipe is with a power circular saw and a special metal cutoff blade. The disc-shaped blade, which has no teeth, fits on the saw like a regular blade. It creates a lot of sparks but works very well.

• Heating ducts. Sheet metal ducts can be cut easily with tin snips. You may need to drill or punch a hole first to gain access. Some runs can be disassembled by re moving the connecting sheet metal screws. Rerouting is generally a job for a professional. Not only does estimating the proper heating capacity require specialized knowledge, but fabricating the new ductwork requires a professional’s tools.

• Radiators. The entire system must be drained back to the boiler. Then disconnect the pipes and lift the radiator out. Cut and cap the pipes at the joists or remove them completely, whichever is more convenient.


Removing Plastic Pipe; Removing Copper Pipe


Removing Cast Iron Pipe; Removing Galvanized Pipe

Monday, June 7, 2010 9:37 PST