Repair or Replace? How to Decide

Step 1 — Establish the facts before anyone quotes you

Commission the evidence before soliciting proposals: an independent condition assessment, a moisture survey (infrared or capacitance) to map wet insulation, core samples where the survey is ambiguous, and a review of remaining warranty coverage. A proposal written before this evidence exists is a guess with a price on it.

Step 2 — Run the four decision tests

1. Condition test. How much of the assembly (membrane, insulation, deck) is actually compromised?
2. Economic test. Compare repair cost + remaining life against replacement cost + new life.
3. Risk test. What does failure cost you (tenants, inventory, operations, insurance position)?
4. Timing test. Can the decision be staged, or does deferral compound the damage?

Step 3 — Interpret the results

Evidence picture	Typical path
Dry assembly, localized defects	Targeted repair + proactive maintenance
Dry but UV-tired field, sound adhesion	Restoration coating
Meaningful, spreading saturation of the insulation	Replacement analysis begins in earnest
Widespread saturation, attachment or structural issues	Replacement (staged if evidence supports it)

One hard constraint anchors the analysis, and it is not a rule of thumb: building codes (IBC reroofing provisions) prohibit recovering a water-soaked roof, and trigger full code compliance once work exceeds prescribed thresholds — meaning a “big repair” can legally become a replacement-grade project. That is why the moisture survey, not the proposal, decides this question.

Percentage rules of thumb circulate widely in the trade — a repair-cost share of replacement cost, or a share of roof area found wet, beyond which replacement is said to win. CRI does not publish specific figures for them, because we have not yet identified a citable primary source that establishes them. Ask any consultant quoting one which study it comes from; the answer is informative either way. The four tests above do not need a magic number to work.

When the answer is genuinely “it depends”

Boundary cases are real: a 60%-sound roof with a failing section, a dry roof at code-minimum insulation, a saturated roof on a building being sold next year. In these cases the honest answer is condition-dependent, and the professional assessments — moisture survey, structural review, consultant’s repair-vs-replace analysis — are worth their fee precisely because the downside of guessing is measured in six figures. Per our Methodology, CRI states uncertainty rather than forcing false confidence — and this decision has genuine uncertainty at its boundaries.