Electrical Safety in Existing Homes

Many owners of older homes have experienced “small” renovation projects that have morphed into much larger projects due to identification of safety related issues. Existing structures can present challenges to homeowners, as they make changes over time. Unfortunately, as both homeowners and contractors delve into a project, they find a variety of latent issues — from mold to hidden safety issues. As an expert, it is important to be able to help homeowners navigate and resolve the electrical safety issues they uncover. From the simple to the complex, it is critical to be a part of the solution as a resource, and to provide guidance on how to best address the electrical issues at hand. As we apply new code changes to existing homes, your skills and knowledge are ever so important to safety. Understanding your boundaries are also very important as areas of the structure that may be exempt from your inspection may still present safety violations that you may need to address in some way. Renovation work in existing homes presents challenges to all involved.

Do-It-Yourself Electrical Solutions May Yield Safety Issues

Although home owners frequently will not attempt plumbing or drywall projects, they often feel comfortable doing electrical work. To some it may seem as though connecting electrical cords together, routing them through rafters and holes in studs is simple and straightforward. Throughout the life of the structure, these changes occur and are typically covered up and hidden, awaiting the reveal during a future renovation project. Contractors and inspectors often encounter slipshod and unsafe electrical installations when walls and ceilings are opened up during renovations. It is critical to be able to identify work that does not meet code and that poses safety concerns.

Imagine being the contractor hired to renovate a bathroom. The electrical inspector arrives to review the installation and finds a variety of issues — from junction boxes in the ceiling to a few illegal splices with knob-and-tube wiring tucked neatly away in some nook or cranny. These were not installed by the current contractor, yet the safety concerns exist all the same. They are likely to hold up the project and add additional costs. These situations can present a challenge to the inspector and contractor on the project, as all work together to arrive at a safe and acceptable solution.

The application of the arc-fault circuit interrupter (AFCI) in an existing home can present challenges as well. Much like the AHJ who spots code and/or wiring issues when visible, the AFCI can detect wiring issues that are hidden from plain sight. Unlike the AHJ who can physically show the problem to those involved and explain the violation, the AFCI detects and isolates problems that may be behind walls and cannot offer the extensive information that may be necessary to resolve the identified problem. The investigation and resolution, although not planned for by the contractor, is worthwhile as resolution of wiring problems can prevent loss of life and property.

Facts and Figures, Scope of the Problem

According to the American Housing Survey for the United States (2010 version), there are more than 130 million homes in the U. S. — 111 million are occupied year-round, 13.9 million are vacant, and 4 million are seasonally occupied. Approximately one-third of these homes are more than 50 years old, and some of these were built without an inspection.

Aging Infrastructure

In 2008, the Fire Protection Research Foundation issued the “Residential Electrical System Aging Research Project” report, which presents a summary of a study on existing homes and is available from the NFPA web site www.nfpa.org. This project conducted a detailed review of homes across the U. S., ranging in age from 30 to 110 years. We can all learn from this research, as both professionals and homeowners. Instances of corrosion and damaged conductors were documented. The investigation revealed: Some of the knob-and-tube wiring found could not hold up to dielectric tests conducted on retrieved samples. The knob-and-tube in some instances had brittle insulation which was worn off at entrances to electrical boxes and luminaires. Service enclosures were found in poor repair and not suitable for their installation. The images and findings included within this study reveal a reality that many of us face when walking into a renovation project as a homeowner or as an electrical professional. A key finding was that numerous dwellings built over the last century are still relying on an electrical infrastructure that is original to the building and is antiquated. The electrical systems of the early or mid-twentieth century are not designed to accommodate the demands of today’s electrical loads and appliances. Upgrades to this infrastructure rarely occur for there is no incentive to address the many problems inside the structure. Unlike energy related changes in the home, modifications to improve the safety of the dwelling unit is not rewarded in tax rebates.

Renovation — The Critical Eye

It is important to keep in mind that the electrical distribution system of a home changes over time. As both inspectors and homeowners, we should be keenly aware of potential electrical concerns, and we should exercise caution during renovation projects.

Often, wiring in many older homes may not have been installed and/or inspected according toNECrequirements and, moreover, was modified or installed without knowledge or understanding of current electrical safety concerns. Modification of a circuit that has been installed and inspected to a version of theNECcan be uneventful and result in a very sound installation. On the other hand, modification to a circuit that has problems may be accomplished per theNational Electrical Code, while at the same time pushing the limits of the installation due to the changes made over the years. For example, a length of wire was found behind a wall that was spliced into an existing circuit, and then covered up with plaster. The splice was illegally performed, hidden, and included a wire selection that had a smaller ampere rating than the rated conductor to which it was connected. Additions to a circuit such as this may present a problem. Adding load to this circuit could push the limits of the wire that was poorly chosen in the hidden splice. The integrity of the infrastructure is important when adding or modifying circuits in holder homes. We assume a level of risk when extending a circuit in an older home without the comfort of knowing the condition or history of changes to the entire branch circuit. Unfortunately, many homeowners do not have the technical knowledge required to understand the impact that their changes may have on the integrity of the electrical distribution system of their home. As electrical professionals who do know and understand, we are faced with the opportunity to educate and guide through our involvement. Unfortunately not everyone pulls a permit and not every jurisdiction requires an inspection.

Is Your Foundation Strong?

Knowing the current code and being able to identify an appropriate (and unsafe) installation is both an art and a great skill. When inspecting older homes, getting back to the basics and finding safe compromises may be necessary as we mesh the latestNECrequirements with the realities of 1953 construction practices.

Identifying the problems and violations can seem like a disaster for contractors and homeowners alike, as they see their hopes of completing the job on time and budget diminish. For the homeowner or even the contractor, the violation or problem that inspectors identify could be uncharted waters. Your guidance and experience is important. For example, your contractor may not have included AFCIs on the project because he/she thought it would not function on a two-wire system. Knowing AFCIs are required but not sure if they will function should lead you to leverage your resources to determine the correct answer and offer accurate guidance.

Your communication skills are just as important as your technical capabilities once code violations or safety issues are located. Marrying good technical knowledge with good communication skills can ensure a balance is reached that will not compromise safety and not break the budget for the project. Everyone needs to be involved in the decisions made to address problems found including the owner, contractor, inspector and any other vested parties. Resolution of found problems will take a commitment of funding and time. Your resources can be your best asset when formulating your message and direction for resolution. Proper guidance and product knowledge can go a long way to getting the project to pass inspection and making for safer homes.

Thomas A. Domitrovich
Thomas Domitrovich, P.E., LEED AP, is vice president of technical sales at Eaton, as well as an electrical engineer. He is actively involved with various electrical industry organizations, focusing on the continued growth of electrical safety. He sits on NFPA Code Making Panel 2 for the continued development of the National Electrical Code (NFPA 70).