# Knob and Tube Removal in Los Angeles

> Knob and tube removal in Los Angeles: disconnecting old runs, clearing dead wire from attics, proving runs are dead. Start with a circuit map of your house.

URL: https://laknobandtube.com/knob-and-tube-removal/

Disconnect old runs for good, prove they are dead, and pull out the ones that are worth removing.

Questions answered

Last Updated: October 24, 2026

**19.1%** of homes in the City of LA were built before 1940, by the Census Bureau's count

**Express** LADBS issues nearly every house rewire permit as an express permit, with no plan check

**394.12** California's rule on insulating over knob and tube, explained in plain terms

[LA Knob and Tube](https://laknobandtube.com/) handles knob and tube removal across Los Angeles, Pasadena, Glendale and South Pasadena: disconnecting old runs so they can never be energized again, proving they are dead, and taking out the ones worth removing. The work is carried out by licensed and insured electrical contractors. Removal is not the same thing as replacement. It deals with wiring that no longer needs to carry power, either because new circuits have already taken over its job or because a remodel left it orphaned years ago.

An attic over a pre-war house can hold both kinds. A run of porcelain knobs crossing the joists might be the live feed for two bedrooms, or it might be a circuit that was cut off when the kitchen was redone in the 1980s and simply left there. From a ladder, they look the same.

## What happens on the first visit

The first visit maps live, dead and mixed circuits before anyone talks about removal. At the panel, each circuit is identified. In the attic and crawlspace, the visible runs are followed to see where they start, where later wiring was tied in, and where they end. Outlets and lights are matched to circuits, so the map shows which runs still feed something.

That map sorts the old wiring into three groups. Live runs have to be replaced before they can be disconnected, and the [partial replacement](https://laknobandtube.com/partial-knob-and-tube-replacement/) or [whole-house rewiring](https://laknobandtube.com/whole-house-rewiring/) pages cover that work. Dead runs can be removed or abandoned in place. Mixed runs, where modern cable feeds a stretch of knob and tube or the other way round, need the most care, because cutting the wrong end can take power from a room that still depends on it.

## Disconnection and physical removal are separate choices

Disconnection is the step that matters for safety. A retired run is cut off at its source, at the panel or at the splice where it joined a live circuit, and again at its last device, so there is no path for it to be energized by accident. Once both ends are dead and the conductors are cut back, the old wire is inert. It cannot carry current, overheat or arc.

Physical removal is a second, separate choice about what to do with that inert wire. In an open attic or crawlspace, the accessible conductors, knobs and tubes can be taken out with no openings at all. Inside a closed plaster wall, removing a dead run would mean opening the wall for no electrical benefit, so the usual answer is to leave it where it is and record it. The guide to [active and abandoned knob and tube](https://laknobandtube.com/guide/active-vs-abandoned-knob-and-tube/) covers how the two states are told apart.

## Abandoned runs in attics and crawlspaces

Dead runs in open spaces are the ones most worth removing. They get in the way: an attic about to be insulated or a crawlspace about to get a [seismic retrofit](https://laknobandtube.com/guide/seismic-retrofit-and-rewiring/) is easier to work in without old wire strung across it. They mislead: the next electrician, inspector or buyer’s home inspector who sees porcelain in the attic has no way to know it is dead without testing it, and a report that says “knob and tube observed” can cause trouble at a sale or renewal. And they hide things: a tangle of retired wire makes it harder to see the live wiring that remains.

Removing them is also a chance to look. Where old runs come out, the framing they crossed and the condition of any remaining live wiring nearby are easier to see.

## Remodels and open walls

A remodel changes the math. When a kitchen or bathroom wall is opened to the studs, any knob and tube inside it is exposed, and removing it adds little to the work. The same goes for ceilings opened for new lighting. The thing to settle before demolition is whether those runs are live. A wall opened for a remodel can contain an old circuit that still feeds a room on the other side, and cutting it without knowing leaves that room dark or, worse, leaves a live end buried in debris.

If the remodel is the trigger, the circuit map should come before demolition, not after. The [replacement process guide](https://laknobandtube.com/guide/knob-and-tube-replacement-process/) explains how wiring work is sequenced around other trades.

## How dead runs are verified

A run is called dead only after it has been checked at more than one point. The first check is at the source: the circuit is switched off or the splice is cut, and the run is tested to confirm nothing is present. The second is at the far end, at the last device or the cut end in the attic. The third is along the run wherever it can be reached.

The reason for more than one check is that old houses are not always wired the way the panel suggests. A later owner may have tied a knob and tube run into a second circuit, or shared a neutral between two circuits, so a run can read dead from one end and still carry current from another. Testing is done by the electrician with the right instruments. If you find old wire in your attic, do not touch, pull or cut it to see whether it is live; the [identification guide](https://laknobandtube.com/guide/how-to-identify-knob-and-tube/) covers what can safely be seen from a distance.

## What stays inside closed walls

After a rewire, some dead knob and tube is normally left inside plaster walls and ceilings, since taking it out would mean opening them. That is expected and, once disconnected at both ends, it is inert. The useful thing is a written record: which runs were retired, where they were cut, and which rooms they used to feed. Where a dead run disappears into a wall from the attic, the short visible end is left identified, so the next person who sees it knows what it is.

That record is what a buyer’s inspector or an insurer can rely on, and it is the difference between “knob and tube observed” and “knob and tube present, disconnected and abandoned.” If the house is going on the market, the [seller’s guide](https://laknobandtube.com/guide/selling-a-house-with-knob-and-tube/) covers how that record is used in escrow.

## Permits and inspection

Disconnecting old runs is part of the permitted electrical work that replaces them. In the City of Los Angeles, that permit comes from LADBS, and the inspector checks the new wiring before walls are closed and at the end. Pasadena, Glendale and South Pasadena issue their own permits. Whether removing already-dead wiring on its own needs a permit is confirmed with the building department for the address. The [Los Angeles rewiring permit guide](https://laknobandtube.com/guide/los-angeles-rewiring-permit/) covers who pulls the permit and what is inspected.

## Access and cleanup

Removal in an attic or crawlspace needs room to move. Where attic clearance is low or the crawlspace is tight, removal takes longer and may be limited to the runs that can be reached safely. Blown-in insulation already covering old runs makes removal slower and dustier, and the [attic insulation page](https://laknobandtube.com/knob-and-tube-attic-insulation/) covers how that interacts with live wiring. Removed material is bagged and taken out, and the attic or crawlspace is left clear of it. No plaster is opened only to remove dead wire unless you ask for it, and if you do, the quote should name each opening and who patches it.

## What removal costs

Removal has no single published price, because it is usually part of a larger job. What moves it is how many retired runs there are, how open the attic and crawlspace are, whether insulation already covers the old wire, and whether any walls are opened for it. The [quote checklist](https://laknobandtube.com/guide/rewiring-quote-checklist/) explains how to make sure removal is written into a quote rather than assumed, and the [LA cost guide](https://laknobandtube.com/guide/knob-and-tube-replacement-cost-los-angeles/) covers the rewiring it usually accompanies.

## What's included

- A circuit map that separates live, dead and mixed runs before anything is cut
- Disconnection of retired knob and tube at the panel or splice point and at the last device
- Verification that each retired run is dead at its ends and at accessible points along it
- Removal of accessible abandoned conductors, knobs and tubes in the attic and crawlspace where agreed
- Short ends left visible and identified where a run continues into a closed wall
- A written list of abandoned runs that remain in walls and ceilings
- Cleanup of removed material from the attic and crawlspace

## Leave it in place or take it out

|  | Disconnect and abandon in place | Disconnect and physically remove |
| --- | --- | --- |
| What it means | The run is cut off from power at both ends and left where it is | The accessible conductors, knobs and tubes are taken out |
| Where it fits | Runs inside closed plaster walls and ceilings | Open attics, crawlspaces and walls already open for a remodel |
| Openings | None beyond the rewire | None in open spaces; more if walls would have to be opened only for removal |
| Later confusion | Dead wire can be mistaken for live by the next person | Nothing left to mistake in the areas cleared |
| Before insulation | Leaves the question of whether attic runs are truly dead | Clears the attic floor before insulation goes in |

## Related resources

- Decision Guide [Is knob and tube still active in your house, or abandoned?](https://laknobandtube.com/guide/active-vs-abandoned-knob-and-tube/)How live, dead and mixed wiring is told apart, why the answer is rarely visible, and what it changes for an insurer, an insulation job and removal.
- Learn [How does knob and tube replacement work, from the first visit to the final inspection?](https://laknobandtube.com/guide/knob-and-tube-replacement-process/)Each stage depends on the one before it. Here is what has to be known before the next step starts, and where the path splits by house.
- Learn [How do you identify knob and tube wiring?](https://laknobandtube.com/guide/how-to-identify-knob-and-tube/)A look-only guide to the clues in attics, crawlspaces, fuse boxes and rooms, and why what you can see is never the whole answer.
- Decision Guide [What should a rewiring quote include, and how do you compare two of them?](https://laknobandtube.com/guide/rewiring-quote-checklist/)Two quotes for the same house can be thousands apart because they describe different jobs. This list shows what to look for and how to line them up.

## How a job runs

1. First call What you have seen, the age of the house, and any inspection, insurer or escrow deadline.
2. Walk-through and circuit map Which runs are live, which are dead, the panel, attic and crawlspace access, and where openings would go.
3. Permit and rewire Circuits are replaced in sequence, so most of the house keeps power on most days.
4. Inspection and patching The city inspection, a labeled panel, and the openings closed as the quote describes.

## What this work looks like

Removed white porcelain knobs and tubes laid out on a wood workbench

An attic floor cleared between the joists before new insulation

A gray junction box with a blank cover mounted on an attic rafter

The cut, taped end of an old cloth-covered cable on an attic joist beside red-handled pliers

## Removal questions

### Can disconnected knob and tube be left inside the walls?

Yes. Runs that are disconnected at both ends and verified dead are usually left inside closed walls and ceilings, because pulling them out would mean opening plaster only to remove wire that can no longer carry current. What matters is that they are truly dead and recorded.

### Is knob and tube removal the same as replacing it?

No. Removal deals with wiring that no longer needs to carry power. If a run still feeds outlets or lights, it has to be replaced with new circuits before it can be disconnected, or those rooms lose power.

### How is old knob and tube proven dead before it is removed?

It is checked at more than one point: at the panel or splice where it was cut off, at its last device, and at accessible spots along the run. A run can be dead at the panel and still live through a later splice into another circuit, which is why one test is not enough.

### Should knob and tube be removed before attic insulation goes in?

It often makes sense. Clearing dead runs from the attic floor removes any doubt about what the insulation is covering, and it is easier to do before insulation than after. Live runs are a different question, covered on the attic insulation page.

### Does removing abandoned knob and tube help with insurance?

It can help the paperwork, because a carrier usually cares about active knob and tube and cleared runs are easy to show. It does not guarantee acceptance. Ask your carrier what it needs in writing before deciding how much to remove.

## Related services

### Partial replacement

Replace the live circuits that matter now and document exactly where the old system stops.

### Attic insulation

Certify the old wiring under California's exception, or replace the attic circuits first and insulate without conditions.

### Whole-house rewiring

Replace every old branch circuit, knob and tube or not, and add the circuits and protection a modern house needs.