Can I Reuse Old Cabling in a Retrofit? A Pro Explains
Have you ever opened a wall during a renovation and thought, “Those wires still look fine, why not keep them?” You’re not alone. At Camali Corp, we get that question all the time.
Reusing cabling might sound like a smart way to save money—less demolition, less waste, fewer delays. But there’s a catch: old wires can quietly cause big problems. They might not carry enough data, could overheat, or even cause safety issues like tripping breakers.
Real Example: When “Good Enough” Wasn’t
A regional bank we helped last spring wanted to turn 6,000 square feet of office space into a mini data center. The old Cat5e cables seemed okay, until testing showed 18% data loss. If they hadn’t upgraded, their network would lag and cameras wouldn’t power up. After a full inspection, we replaced 70% of the cables and reused the rest. That saved a full day of work and ensured their system could handle today’s speeds.
That’s the goal—keep what works, replace what doesn’t. This guide will walk you through safety checks, costs, and signs that it’s time to pull new cable.
Fact check: The NFPA reports that wiring and related equipment caused 7% of all U.S. home structure fires between 2015-2019. That same heat risk applies to commercial cable trays packed with aging PVC.
Why Owners Want to Reuse Wiring (and When It Backfires)
Reusing cables sounds great, especially since labor costs can take up 40–60% of your budget. But skipping an inspection can lead to big problems. Here’s why:
- Hidden De-ratings – Modern PoE lighting and Wi-Fi 6E draw more amps (power), pushing older 24-AWG conductors past safe temps.
- Code Drift – Cables installed pre-2002 may lack fire-resistant plenum jackets now required in today’s fire safety codes.
Before making a decision, it’s smart to talk to a structured cabling expert. Camali Corp’s structured cabling services cover inspections, upgrades, and compliance checks.
Code & Safety Checklist: 5 Tests Your Cable Must Pass
Before reusing any old wiring, test it using this list:
1. Jacket Integrity & Fire Rating
Run your fingernail down the outer jacket. If it flakes or cracks, the cable has heat damage. Per the 2023 NEC §725.144, damaged insulation can’t be reused in walls or ceilings.
2. Conductor Gauge vs. New Load
Use NEC Chapter 9 to match the wire gauge (AWG) to how much power (ampacity) your new system uses. Up-sizing equipment but not cable is the fast lane to voltage drop. Too small = overheating risk.
3. Insulation Age
PVC cables last about 25 years; better-quality ones like LSZH may last longer. If you’re not sure how old it is, plan for replacement.
4. Termination Health
Look for rust, burnt spots, or loose connectors. Even if the wire tests fine, the ends should be redone for a solid connection.
5. Documentation & Labeling
NEC §300.4(D) now requires a clear pathway ID. Unmarked cables aren’t code-compliant and can cause confusion later.
Cost Math: Replace vs. Reuse
| Full Replace | Selective Reuse | |
| Material | $550 per 100 drops | $180 per 100 drops |
| Labor | $1,100 | $450 |
| Downtime | 2 days | Less than 1 day |
| 5-Year Upgrade Risk | Low | Medium to High |
Rule of thumb: If more than 30% of test points fail, replacing all cables is usually the smarter long-term choice.
Camali’s 6-Step Cabling Inspection for Retrofit Projects
At Camali Corp, we use this proven method to assess old wiring:
- Walk-through and thermal scan
- Check cable age using the label (pull-sheet) or a tracer/testing dye
- Run data tests (Fluke DSX) to check 10-gig rating
- Spot safety gaps (like fire barriers or wire bends)
- Plan next steps: keep, re-terminate, or pull
- Provide a signed compliance letter for your local inspector (AHJ)
Expert tip: In our own retrofit projects, this process has helped us cut client change orders by 32% on average.
When to Pull and Replace: Red-Flag Scenarios
- Cables that are older than 25 years and run through ceiling plenum (space between a building’s structural ceiling and a suspended ceiling)
- Visible green corrosion on the copper
- Cable is tied directly to a sprinkler pipe (this violates NFPA 13)
- Plans to upgrade from 1 Gbps to 10 Gbps backbone
- No grounding conductor in power circuits
These are safety issues, don’t take the risk.
Next Steps & Free Site Walk-Through Offer
Still unsure about your wiring? Camali Corp offers a no-obligation, 60-minute on-site inspection. We’ll sample-test five random drops, inspect your electrical system, and give you a clear list of what to keep or replace.
We also offer ongoing service contracts to help you stay code-compliant and avoid surprise failures.
Book your inspection here → Camali Electrical Services
