The wiring in your home is act like a main road of power that feeds everything electrical in the household. Over time, parts of it can become damaged or deteriorated and may present a serious fire or shock hazard. But age alone doesn't mean wiring is inherently unsafe, nor does old wires and cablesautomatically have to be replaced. It takes an experienced professional to properly assess the condition of old wiring and its ability to handle the electrical loads of your home, but there are a few things you can check for that can give you an early indication of where it stands.
Here are some typical problems with old wiring that are possible hazards and may indicate the wiring should be replaced:
1. Broken, absent, or injured wire insulation, revealing the metal part of the wires: This is a very common issue, and wires with damaged insulation should be addressed by a professional.
2. Wiring bounded by building insulation of any type, be very cautious when insulating a loft to make sure you are not surrounding active knob-and-tube running in joist cavities wiring with loose fill or batt insulation.
3. Visible connections (not in an electrical box) wrapped with modern plastic electrical tape, usually indicating the wires are not soldered: Exposed splices should be soldered.
Fuses in the fuse box that are bigger than 15 or 20 amps: old wiring wasn't sized for today's big applications, which may require 30-, 40-, or 50-amp amenity. A 30-amp or larger fuse used in a knob-and-tube system indicates an "overused" circuit, which is highly dangerous.