Knob and Tube Wiring in Colorado - Should You Replace It?
Sound electrical has been a crucial part of every home since electricity was first introduced into homes in the late 19th to early 20th centuries. During those early years of residential electrical, rudimentary “knob and tube” wiring in Colorado and nationwide was the standard method of bringing power to lights and outlets. These early systems were much different than the safer and more advanced sheathed copper wire and GFCI protected plugs now used in today’s residential electrical applications.
Throughout Colorado’s Front Range, it isn’t uncommon to find homes built in the early 1900s that are still running on the knob and tube system originally wired into the house. Needless to say, 100+ year old electrical systems are not up to code; they can pose not only serious safety hazards for those living in the house and also create issues when the property is being bought or sold.
In today’s blog post, we’re taking a look at knob and tube systems to elaborate more on why they’re considered unsafe.
Active Knob and Tube Wiring: The Most Dangerous Thing a Home Can Have
Active knob and tube wiring is arguably one of the largest safety issues a house could have. This is because it poses serious fire hazards and shock hazards - and could show no signs of an issue until it is much too late.
Fire and Shock Hazards:
Every year, there are dozens of instances in which knob and tube wiring causes a house fire as a direct result of outdated knob and tube wiring. But it isn’t just one feature of knob and tube wiring that makes it susceptible to triggering electrical fires - in fact, there are multiple different issues with knob and tube systems that are considered serious fire hazards.
No Ground Wire: Unlike the systems used today, knob and tube systems are ungrounded - this means the wiring and devices (outlets) don’t use a ground wire. Ungrounded electrical systems are one of the leading causes of electrical fires.
Ground wires are an essential safety feature that have been a standard safety requirement for all electrical wiring - both commercial and residential - since the 1960s. A ground wire is a third wire (in addition to the line and neutral wire that is sheathed) that protects against fires and catastrophic damage to electrical components within the electrical system by routing excess electrical load away from devices like plugs and switches and instead sending that excess power into the ground, where it will be dispersed harmlessly.
Without grounding throughout an electrical system, wiring within the wall or at the outlets is more susceptible to unchecked arcing and shorting, which in turn can lead to burned, melting wires and electrical fires.
Unsheathed Wiring and Heat: The wiring throughout knob and tube systems are unsheathed and wound around porcelain knobs to hold wires in place. Wire sheathing dissipates heat - it prevents construction material near the wires (like insulation) from getting hot and sparking a fire. But knob and tube systems were used before sheathing was invented. Instead of relying on sheathing to dissipate heat from wires, knob and tube systems rely on open space and air within a wall to dissolve heat. But over decades, many homeowners add insulation to walls and attic spaces without realizing that doing so turns their electrical system into a serious fire hazard.
When unsheathed knob and tube wires come too close to insulation, it can create enough heat to cause a fire. In fact, it is now against N.E.C. code to allow knob and tube wiring to come into contact with insulation.
Shock Hazards: Today, wet-rated plugs protect against the possibility of being shocked while using an outlet in a wet environment such as a bathroom or kitchen. Unfortunately, the technology to prevent shocks in wet locations just didn’t exist in the electrical systems of the 1900s. Knob and tube systems are not rated for wet locations. Instead, they pose a shock hazard when being used in areas where moisture is present, especially when located directly next to a sink or shower.
Insufficient for Modern Day Electrical Needs
Between the early 1900s and today, the electrical load a home carries has increased significantly.
In the 20th century, electrical systems were really only required to handle very basic functions: keep lights on and power minor appliances. Today, however, the electrical in a home is responsible for keeping the lights on, charging phones and laptops, powering multiple large household appliances, bringing electricity to constantly plugged in devices like televisions and game consoles, and running air conditioners and water heaters - often, all at the same time.
Unfortunately, the knob and tube systems that were once cutting edge in the 20th century simply aren’t designed to handle the vast electrical load that we now demand of residential electrical systems. This constant overloading of knob and tube systems with modern day electrical needs creates more strain on an already outdated system, furthering risk of electrical issues that pose problems not only to convenience of use, but (again) the safety of using the electrical system.
A Major Obstacle When Selling (or Buying) a Home
Because of the well-documented dangers and risks associated with knob and tube wiring, selling or buying a home with active knob and tube electrical is a major obstacle.
Home inspectors and property insurance companies alike typically keep an eye out for homes that have antique electrical systems.
Hung up on Home Inspections: During the purchase of a home, buyers often (and, depending on the type of loan used, are required by lenders to) obtain a home inspection. Active knob and tube wiring is a major “red flag” that comes up on home inspections that can not only devalue a property, but also cause a buyer to terminate or renegotiate their offer due to well-founded safety concerns.
Higher Property Insurance: Homeowners insurance companies are risk averse. Often, homes with active, outdated knob and tube electrical will trigger an increase in the policy premium cost due to the well documented risks of house fires with these older systems.
Antique homes built in the early 1900s have an undeniable charm. As they say, “they just don’t build them like that anymore.” And while the aesthetics and floorplans of these older homes are timeless, they don’t install knob and tube electrical like that anymore for the simple fact that it is dangerous. If you live in - or are buying - a home built in the 20th century, having your electrical system inspected to determine if a re-wire is necessary is an invaluable investment in safety.
