Replacement vs. Recover Analysis

The recover-versus-replace decision is the most consequential scope call on an aging commercial roof. Getting it wrong in Atlanta - recovering over wet insulation, or replacing when a recover would have performed - is a six-figure mistake. We make the call from data: moisture cores, deck inspection, membrane condition, and a written recommendation the owner can take to a capital committee.

Every aging flat roof in Atlanta eventually reaches the recover-versus-replace decision point. The economics of the two paths are significantly different: a recover over a sound, dry existing insulation stack typically costs 50 to 65 percent of a full replacement and can add 15 to 20 years of service life. A full replacement tears off the existing system, addresses any wet or deteriorated insulation, installs new insulation to current Georgia energy code R-value, and installs a new membrane with a full 20-year NDL warranty. The right answer depends on the condition of the existing system - specifically the moisture content of the existing insulation and the condition of the deck below it.

Atlanta's climate makes this decision harder than in drier markets. High relative humidity from June through September drives condensation into insulation stacks through minor membrane failures. Atlanta's 53 inches of annual rainfall, delivered in high-intensity afternoon thunderstorms, creates continuous moisture pressure on aging seams and flashings. The result is that Atlanta commercial roofs have higher rates of insulation saturation than comparable buildings in drier markets like Phoenix or Denver - a fact that shifts the statistical probability toward replacement in the recover-versus-replace analysis.

Our replacement-versus-recover analysis is a structured engagement with three components: a field inspection with moisture core sampling, an analysis of the findings against the recover threshold criteria, and a written recommendation with the supporting data. The recommendation is not a sales pitch for the higher-revenue option - it is a data-driven scope call based on what we find in the cores and in the deck inspection.

Moisture cores are the primary data input for the recover-versus-replace decision. A moisture core is a plug of material - membrane, any insulation boards - extracted from the roof at a representative location and tested for moisture content. We pull cores in 5 to 10 locations on most Atlanta commercial roofs, distributed to cover the full roof area including drain sumps, parapet perimeters, penetration clusters, and mid-field areas. Core locations are selected based on the roof zone diagram and any visible surface indicators of likely moisture infiltration.

Atlanta-specific core interpretation: We use a 25 percent wet-insulation threshold as the primary recover/replace decision criterion. If fewer than 25 percent of cores read wet, the recover path is viable - the wet insulation at wet-core locations is replaced prior to recover, and the recover system is installed over dry insulation. If more than 25 percent of cores read wet, full replacement is the right scope. The 25 percent threshold is a practical standard informed by manufacturer warranty requirements and the economics of the two paths - at saturation levels above 25 percent, the cost of targeted insulation replacement approaches the cost differential between recover and replace, and the risk of residual moisture voids the new warranty.

Infrared scanning as a supplemental tool: For large-footprint Atlanta roofs - 100,000 square feet and above - we supplement moisture core sampling with infrared thermal scanning conducted at dusk or dawn when thermal contrast between wet and dry insulation is highest. The infrared scan provides a moisture map of the entire roof that guides core placement for confirmation sampling. This is most relevant for the large-footprint industrial and warehouse buildings in the Marietta corridor and the Hartsfield-Jackson logistics ring, where pulling cores across the full roof area without infrared guidance is not cost-effective.