Commercial roof recover systems for Louisville buildings — single-ply and modified bitumen recover over qualifying existing membranes, with core-pull eligibility assessment and manufacturer warranty paths.
A roof recover installs a new membrane system directly over the existing roof, eliminating tear-off cost and disruption when the existing insulation is confirmed dry. For qualifying Louisville commercial buildings, recover delivers a 15-20 year warranty at 60-70% of full replacement cost.
A roof recover is not the same thing as a patch job. It is a complete new roofing assembly — new insulation cover board, new membrane, new flashings, new manufacturer warranty — installed over an existing roof that has been confirmed dry through core pulls. The existing system stays in place. The new system is designed and warranted as if it is a new installation, because structurally it is.
Louisville's commercial building inventory makes recover a legitimate tool in the scope arsenal. The industrial and warehouse buildings concentrated in Jeffersontown's Bluegrass Industrial Park, the logistics corridors along I-64 and the Gene Snyder Freeway, and the older retail centers on Shelbyville Road and Bardstown Road have large flat-roof footprints where the cost difference between recover and full replacement is significant — and where the building's remaining functional life justifies a 15-20 year system rather than a 30-year full replacement.
We run recover work on qualifying Louisville buildings. The qualification step is not optional and is not abbreviatable: core pulls at representative locations across the full roof area, with wet insulation at more than 25 percent of cores disqualifying the building from recover eligibility. A recover system installed over wet insulation voids the manufacturer warranty within 18-24 months when the trapped moisture migrates into the new insulation layer. We have seen this happen on Louisville buildings where a previous contractor skipped the core-pull step. We do not skip it.
The eligibility process for a Louisville commercial roof recover starts with a moisture survey — infrared thermography or ELD depending on the substrate — followed by core pulls at a density of one per 3,000 to 5,000 square feet, with additional pulls at any flagged areas. We inspect each core for insulation moisture content, ply adhesion on existing multi-ply systems, and deck condition at the underside of the insulation.
Kentucky building code follows the single-recover rule from the IRC and IBC: one recover layer is permitted over an existing roof system before tear-off is required. We document the existing layer count in every core investigation and include that finding in the written assessment. Louisville buildings in the 30-to-40-year age range — particularly warehouse and industrial buildings in Jeffersontown and the west Louisville industrial corridor — are more likely than their owners realize to already have one recover layer in place from a mid-cycle job done in the 2000s or 2010s. Finding that layer in a core changes the scope from recover to full replacement, and the owner needs to know that before anything is ordered.
Parapet and drain condition are the other eligibility checks. Parapets on older Louisville commercial buildings have flashing termination conditions that range from sound to actively failing. A recover is not worth specifying if the parapet flashings are deteriorated to the point where new termination flashings cannot be properly anchored — in that case, the parapet work cost approaches what the flashing portion of a full replacement would cost, and recover's cost advantage diminishes. We assess parapet condition specifically and include that finding in the eligibility report.
TPO recover over existing single-ply or BUR: The most common recover path on Louisville commercial buildings. A 1/2-inch cover board is mechanically attached over the existing system to create a smooth, uniform surface and provide a fastener substrate. New 60-mil or 80-mil TPO is then mechanically attached to the cover board in a pattern designed against the building's wind-uplift zone per IBC 2021. The manufacturer's warranty (typically 20-year NDL from GAF, Carlisle, or Manufacturer Warranty Coordination) is issued on the completed assembly as a new system warrant.
Modified bitumen recover over BUR: For Louisville buildings with existing BUR systems in fair condition, SBS modified bitumen applied in a self-adhered or torch-down configuration over a cleaned and primed BUR surface is a legitimate recover path that keeps the bitumen family consistent through the assembly. Modified bitumen recover is appropriate when the existing BUR is in fair structural condition — dry cores, minimal blistering — and the owner wants a familiar system profile with a 10-15 year warranty path.
Insulation add in the recover assembly: One advantage of a recover over a tear-off is the opportunity to improve the insulation value of the assembly without removing the existing system. We regularly specify an additional layer of polyiso above the existing insulation in the recover assembly to bring the total R-value up to current Kentucky energy code requirements (R-25 minimum for low-slope commercial). This is especially relevant for Louisville warehouse and industrial buildings built before ASHRAE 90.1 required meaningful roof insulation — buildings from the 1970s and early 1980s that may have 2 to 4 inches of aged polyiso with a degraded effective R-value of R-8 to R-12.
Recover is the right scope when: core pulls confirm dry insulation across more than 75 percent of the roof area, the existing system is at its first recover (no prior recover layer in the core), the deck is confirmed sound, the parapet flashings can be properly terminated in the recover assembly, and the owner's capital horizon for the building is 15-20 years. In that scenario, recover delivers a warranted new system at 60-70% of full replacement cost with less site disruption and less landfill material.
Full replacement is the right scope when: core pulls show wet insulation at more than 25 percent of the field, the building is at its code-allowed recover limit, deck corrosion or damage found during core investigation requires repair work that is only possible with the existing system removed, or the owner's capital horizon is 25-plus years and the economics of a thicker insulation assembly and a longer-warranty system justify the full replacement cost.
We put the recommendation in writing, with the core-pull results documented and the replace-vs.-recover economics stated explicitly. Louisville building owners and facility managers who have been told to replace by one contractor and to recover by another — without core pulls to support either recommendation — need a third opinion backed by actual data. That is what we deliver.
The core pulls tell you. Until someone pulls cores at representative locations across your roof and reads the insulation condition, nobody can give you a defensible recover recommendation. Any contractor who recommends recover without core pulls is guessing, and if the insulation is wet, that guess produces a warranty claim that the manufacturer denies. We will pull the cores and give you a written eligibility determination.
Yes, from most major manufacturers — GAF, Carlisle, Manufacturer Warranty Coordination, Sika Sarnafil — provided the recover assembly is designed and installed to their recover system specifications, the substrate eligibility requirements are met, and the manufacturer's field representative inspects the finished installation. The warranty is issued on the new assembly as a warranted system, not as a repair supplement to an existing warranty. We coordinate the manufacturer inspection and warranty submission as part of every warranted recover project.
On a typical Louisville warehouse or industrial building, a mechanically attached TPO recover with cover board runs roughly $5.50-7.50 per square foot installed. Full replacement with tear-off on the same building runs roughly $9-13 per square foot depending on insulation thickness, deck condition findings, and drain configuration. The recover savings are most pronounced on large-footprint buildings — a 100,000-square-foot Jeffersontown warehouse saves $350,000-$550,000 on a recover vs. full replacement, assuming the building qualifies.
We will pull cores, run the moisture survey, and produce a written recover-eligibility assessment — with a firm recommendation and installed cost estimate if the building qualifies. We serve the full Louisville metro including Jeffersontown, St. Matthews, Middletown, Shively, and Downtown.
Tell us about the building and the roof problem. We'll document it and put a plan in writing — no pressure, no boilerplate.
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