A useful knob and tube inspection checklist covers five things: which circuits are still active, how each one is protected at the panel, what condition the accessible wiring is in, where old and new wiring connect, and what the electrician could not see. If the written report leaves any of those out, ask for it before you rely on the report for an insurer, a sale or a quote.
Philly Knob & Tube arranges knob and tube assessments and replacement across Philadelphia, and licensed electrical contractors carry out the work. Use the lists below to prepare for a visit and to check the finished report, item by item. Nothing here asks you to open, touch or test wiring; every item is something the electrician does and writes down.
Before the visit: what to gather
The electrician can see the wiring. They cannot see the house’s history unless you supply it. Gather what you can:
- The year the house was built and any known renovation dates, especially kitchens, baths and additions
- Any previous inspection reports, including the home inspection from your purchase
- The insurer’s letter or email, word for word, if an insurer has raised knob and tube
- A list of symptoms you have noticed: lights that dim, plates that feel warm, fuses or breakers that trip, outlets that stopped working
- Notes on access: where the attic hatch is, whether the basement ceiling is finished, which closets back onto which rooms
- Plans you have for the next few years, such as insulation, a renovation or a sale
If the building has more than one unit, add one more item: access to every unit, the common areas and any basement storage, arranged in advance with residents. Old circuits in converted houses do not always respect unit boundaries, and a map with a locked apartment in the middle of it is incomplete. The multi-unit page covers that coordination.
The insurer’s exact wording is the item people most often forget. “Is there knob and tube?” and “Is there active knob and tube?” are different questions, and the report should answer the one that was asked.
Questions to ask the licensed electrician
Ask these when you book, so you know what kind of visit you are paying for:
- Will the panel cover be removed so the conductors leaving each breaker or fuse can be identified?
- Will every circuit be mapped to the rooms and devices it feeds, or only a sample?
- Will the attic, basement and any crawl space be entered, and what will happen if one is not reachable?
- Will a few device covers be removed for inspection, and which ones?
- Will the report separate active, abandoned, partial and mixed wiring?
- Will the report say what was not inspected and why?
- Is the report written so an insurer or buyer can read it, or is it a field note?
- If replacement is recommended, will the report be specific enough to price from?
The answers tell you whether you are getting a walk-through with an opinion or an assessment with a record. Both have a place, but they are not interchangeable. The inspection service page describes what that visit involves.
How active circuits should be confirmed
Whether old wiring is live or dead cannot be decided by looking. The checklist below is what the report should show the electrician did. For why each step matters, the active versus abandoned guide goes deeper.
- Circuit identification at the panel. Each breaker or fuse is listed with the type of conductor leaving it.
- Room-by-room mapping. Each circuit is matched to the lights and outlets it feeds.
- Status per circuit. Each circuit is marked as modern, original knob and tube, or mixed.
- Old runs that appear dead. Any conductors found disconnected are noted, along with whether they were confirmed dead at both ends or only at one.
- Method stated. The report says how status was determined, for example by switching circuits off one at a time and testing with proper instruments, not by appearance alone.
Be wary of conclusions drawn from outlets. A three-prong receptacle does not prove a circuit is grounded or modern; it can sit on a two-wire knob and tube run. The three-prong outlet guide explains why. Likewise, old cloth-covered cable is not always knob and tube; the cloth wiring comparison shows how the two differ.
Access, panel and connection questions
These are the conditions that change a recommendation from “monitor” to “replace soon.” A thorough report addresses each one, even if only to say it was not found.
Panel and protection
- Fuse or breaker size on each knob and tube circuit, and whether any appear oversized for the conductor
- Signs of heat at the panel, such as discoloration or melted insulation
- Available space and capacity if new circuits will be needed
Connections and splices
- Splices found in attics, basements and accessible ceilings, and whether they are in boxes
- Places where modern cable joins old conductors, which the splices and junction boxes guide explains
- Evidence of shared or crossed neutrals between circuits; see the shared neutrals guide
Condition of accessible wiring
- Brittle, cracked or missing insulation on exposed conductors
- Conductors that have lost their spacing or support, or rest against framing or pipes
- Damage from rodents, water or earlier renovation work
Surroundings
- Insulation in contact with or covering knob and tube in attics or walls
- Stored items piled on or against exposed runs
- Access paths for replacement: open joists, chases, closets and spaces with no access
If anything on this list turns up heat damage or scorching, the right step is to stop using that circuit and have it dealt with, not to wait for a full plan. The guide to signs old wiring needs attention covers that line.
Documents to request afterward
The visit is only as useful as what is written down. Ask for:
- A circuit list with each circuit’s status, the rooms it serves and its protection
- Photographs of the panel, key splices and typical runs, labeled by location
- A limitations statement naming the areas not inspected and why
- Findings ranked by urgency, separating safety issues from planning items
- A scope recommendation in terms of circuits, not just “rewire the house”
- The electrician’s name and license information, so the report can be traced
If an insurer is waiting, ask whether it wants this report or a separate letter. The insurance letter guide explains what a completion letter can and cannot say, which is a different document from an assessment.
Matching the assessment to its purpose
The same house can need different reports depending on who will read them. Before the visit, tell the electrician which of these applies, because it changes what the report should emphasize.
For an insurer. Underwriters usually want a direct answer to a narrow question: is there active knob and tube, and if so, where? The report should state that answer in the first lines, in the insurer’s own terms, and attach the circuit list. Opinions about condition help, but they do not replace the yes or no the carrier asked for. The homeowners insurance guide covers how carriers tend to phrase the question.
For a purchase. A buyer working inside an inspection contingency needs scope and urgency more than a full map: roughly how many circuits, how reachable, and whether anything needs attention before closing. Time is short, so say so when booking. The buyer’s guide explains how those findings are used in negotiation.
For planning a project. If you already own the house and intend to replace the wiring, the report should be detailed enough to price from: circuit by circuit, with access notes for each floor. That level of detail takes longer to produce and is worth more later, because every bidder can work from the same document.
Red flags in a finished report
Some reports look complete and still leave you without an answer. Watch for:
- “Knob and tube present” with nothing else. Presence is what the home inspector already told you. The assessment should say whether it is active.
- Conclusions with no method. If the report says “circuits appear modern” without saying how that was determined, you cannot tell whether anything was tested.
- No limitations section. Every assessment of an old house has places that could not be reached. A report that names none is overstating its certainty.
- Recommendations without circuits. “Full rewire recommended” with no circuit count gives you nothing to compare quotes against.
- A panel recommendation presented as the answer. A new panel may be useful, but it leaves the branch wiring in place.
None of these makes the visit worthless. Each one is a question to send back before you act on the report.
Reading the report against the checklist
Go through the lists above with the report open. Every box should either be answered or marked as not applicable or not accessible. Gaps are not necessarily a sign of a poor inspection; sometimes an attic is sealed or a ceiling is finished. But each gap should be named, because the next decision depends on knowing what is confirmed and what is assumed.
When the report is complete, it becomes the basis for a quote. If you are weighing options, the partial versus full replacement guide uses the circuit map to set scope, and the hiring guide covers choosing who does the work. To arrange an assessment of your own house, use the contact page.
