Why Old Knob And Tube Wiring Is A Fire Risk In The Attic

Old Insulation in Attic - Why Old Knob And Tube Wiring Is A Fire Risk In The Attic scaled graphic

If you are the owner of an older home, the chances are you fell in love with it because of its charm. Maybe it came with beautiful woodwork, built-in shelving, or nooks. Perhaps it has unique features or flooring that you just can’t find in new homes. It also likely has some things you might not like as much, like old knob and tube wiring in the attic or the walls. Old wiring is an incredibly dangerous risk when it comes to attic insulation

What is Knob and Tube Wiring?

Knob and tube wiring was a commonly used method of providing electricity throughout a home built between the 1880s through the 1940s. It is obsolete to the point that most people these days have never even heard of it. It poses a danger to older or historic homes because the wiring is typically hidden in walls and the attic, and you may not even know it’s there.

Knob and tube wiring consists of a single copper conductor run through porcelain insulating tubes, sometimes wrapped in flexible insulating cloth sleeves where it connects to fixtures. It poses a significant fire risk when it comes into contact with things like attic insulation. Most people don’t know that it’s there and it can be overlooked when buying the home. This is why you should have your attic inspected prior to closing on a home. 

Why is Knob and Tube Wiring Dangerous?

As mentioned above, the principal danger from knob and tube wiring is a fire, often caused by a spark igniting attic insulation or insulation in the walls. Several factors heighten the danger of knob and tube wiring.

The age of the wiring plays a critical role. When installed 50 or more years ago, the average home drew far less electricity than modern appliances and electronics. This means that older wiring can quickly become overloaded, to the point that they pose a fire hazard. Add in the fact that the flexible cloth often used to coat the wires breaks down over time. The result is that you have exposed, overloaded wires that may be in contact with flammable building materials like attic insulation.

Another issue with knob and tube wiring is that they do not include a ground wire. A relatively new invention, the ground wire is a safety feature that helps prevent overloaded wires from sparking a fire. Many modern appliances require three-prong electricity, so older wiring may not even support new electronics.

Further, as mentioned above, they are easy to ignore. Since they are in the hollow spaces of ceilings, walls, or attics, you don’t necessarily see them, even when doing renovations.

What should I do if I have knob and tube wiring?

If you have knob and tube wiring in your home, you’ll want to call an attic professional immediately. We’ll come out, assess the risk, and help you craft a plan for mitigation or replacement. You certainly don’t want to tackle dangerous old wiring on your own, nor do you want to let it go unchecked.

If you have an older home, contact us today. We’ll help you make sure your charming, older home is safe and comfortable for you and your family for years to come.

Contact Your Local Attic Projects: