Prior Fix by Another Company Rework vs Flag vs Decline Decision Tree

Why this matters

You open a system and find work another company did, and it is wrong, substandard, or unsafe. What you do next carries real liability. Rework it silently and you may assume ownership of a problem you did not create and the customer never authorized you to touch. Ignore it and proceed and you may be signing off on a hazard or a code violation that later traces back to your visit. Tear it all out and redo it when a flag and a quote would have served, and you have overstepped scope and overcharged. The prior-work decision is where technical judgment, customer authorization, and legal exposure collide, and the safe path is rarely the reflexive one.

The situation

While doing your authorized job, you encounter pre-existing work by a third party that affects your task, the system's safety, or its code compliance. The prior work might block your repair, might be unsafe regardless of your job, or might simply be ugly but functional. You must decide whether to rework it, flag it for the customer to address, or decline to touch it, and you must keep your own work clean and authorized throughout.

Decision factors

• Safety severity. Is the prior work an active hazard (exposed energized conductor, unsupported gas line, backflow risk) or merely substandard? An active hazard cannot be silently left, full stop.
• Code or permit status. Does the prior work violate code, and would your continuing make you the one who "last touched" a non-compliant assembly? Jurisdictions and inspectors care who signed off last.
• Dependency on your task. Must the prior work be corrected for your authorized repair to function or be safe? If your fix depends on it, you cannot ignore it.
• Authorization scope. What did the customer actually hire you to do? Reworking unrelated prior work without new authorization is outside scope and unbillable as a surprise.
• Liability transfer. Touching prior work can make its future failure your problem. Understand where the line of responsibility moves before you pick up a tool.
• Customer awareness. Does the customer even know the prior work exists or is flawed? Often they do not, and the flag itself is the most valuable thing you provide.

The decision

Stop and flag immediately, regardless of scope, when the prior work is an active safety hazard. Do not silently fix it and do not quietly proceed past it. Inform the customer, document the hazard with evidence, and if it makes continuing your work unsafe, pause until it is addressed. Some hazards (a gas leak, an energized exposed conductor) require making safe on the spot for life-safety reasons, but even then you document and notify rather than absorb it.

Rework it, with new authorization, when the prior work blocks or undermines your authorized task and correcting it is the only way to deliver a safe, functional result. Quote the rework as a separate, clearly described item, get explicit approval, and document that you are correcting third-party work so the liability line is recorded. Never fold it invisibly into your original scope.

Flag and defer when the prior work is substandard or non-compliant but not an immediate hazard and does not block your task. Describe it plainly, show the evidence, recommend correction, and let the customer decide. Record that you identified and reported it; that record protects you if it fails later.

Decline to touch when the prior work is unrelated to your task, not a hazard, and the customer has not authorized you to address it. Reworking it would be out of scope and would needlessly transfer its liability to you. Note that you observed it and leave it for a future authorized visit.

The liability line is the part techs most often get wrong. When you modify, correct, or even significantly disturb someone else's installation, you may become the party who "last worked on" that assembly, and a later failure can land on you regardless of who built it originally. That is why silent rework is dangerous even when it is technically easy: you absorb the risk of work you did not design and the customer never knew changed hands. The protection is explicit authorization that names what you are correcting and why, so the record shows you took on the third-party work deliberately and with consent rather than by accident.

Keep your own work documented as clean even when the surrounding work is not. If you must connect to, build on, or pass through substandard third-party work to complete your authorized task, record the condition you found it in before you touched it and the limits of what you corrected. This separates your contribution from the pre-existing defect, so that if the older work fails later, the record shows your scope and its condition at handoff rather than leaving a single ambiguous "the system failed" that gets pinned on the last name on the invoice.

What to document

• The prior work found, described factually, with photos showing condition and context.
• Whether it is a hazard, a code issue, or merely substandard, and the basis for that classification.
• Whether it affected your authorized task and how.
• The decision (rework, flag, decline) and the reasoning, including the liability consideration.
• For rework: the separate authorization obtained before proceeding.
• For a flag: the recommendation given and the customer's acknowledgment.

References

• Occupational Safety and Health Administration, general-duty and hazard-recognition obligations on identifying and reporting unsafe conditions encountered on a job (osha.gov).
• NFPA 70B, Standard for Electrical Equipment Maintenance, on assessing and documenting the condition of existing electrical work before continuing.
• Plumbing-Heating-Cooling Contractors Association (PHCC), guidance on handling pre-existing and third-party work and the scope-authorization line (phccweb.org).
• National Association of the Remodeling Industry (NARI), standards of practice on documenting existing conditions and obtaining authorization for additional work (nari.org).