Capability

Roof Zone Mapping

A roof zone map is the baseline document that makes every subsequent inspection, repair, and capital planning conversation more efficient. We produce them for Atlanta commercial buildings that have never had one and update them for buildings where the existing diagram is outdated.

Most commercial buildings in Atlanta do not have a current, accurate zone map of their roof. They have whatever was in the closeout package from the last replacement — which may be a sketch on a photocopied floor plan from 2006 — and a folder of inspection reports that reference zones by description rather than by diagram location. When a leak occurs, the facility manager is describing the location by reference to the nearest HVAC unit or the corner of the second-floor conference room. When a contractor walks the roof, they are finding the breach by walking the probable path from the interior complaint to the roof surface. This process works, but it is slower, more error-prone, and less useful for capital planning than a building with a current, photographically documented zone map.

A zone map divides the roof into discrete areas — typically defined by drain catchment, by membrane section, by construction vintage, or by maintenance priority — and assigns each zone an identifier that carries through every subsequent inspection report, work order, and capital planning document. When zone 7 shows up in this year's inspection report, the facility manager can pull the zone diagram and see exactly where zone 7 is, what the condition was two years ago, what repair was done last spring, and what the capital forecast shows for that zone in the next 5-year horizon.

We produce zone maps as standalone deliverables for buildings that have never had them, as part of baseline inspection packages, and as part of capital planning and asset management program setup. For Atlanta's Class A office and institutional building inventory, a current zone map is increasingly a baseline expectation — the major property management firms operating in the Buckhead and Midtown corridors maintain zone diagram standards that their contractor relationships are expected to meet.

What a Zone Map Contains

Base drawing: A dimensionally accurate overhead view of the roof, showing the building perimeter, all rooftop equipment locations, all parapet walls and changes in elevation, all drain locations and scupper locations, and all major penetration groups. For Atlanta Class A buildings with dense rooftop equipment inventories — multiple large air handlers, chillers, cooling towers, telecom equipment — the base drawing requires field measurement rather than reproduction from an existing floor plan.

Zone boundaries: The roof area is divided into numbered or lettered zones with clear boundaries. Zone boundaries follow natural division points — drain catchment areas, expansion joints, changes in membrane vintage, transitions between membrane types on buildings with multiple systems. For buildings where a prior replacement covered only part of the roof, the zone boundary follows the original versus replacement membrane line.

Zone attributes: Each zone carries its current attributes — membrane type and approximate age, insulation type, attachment method, current condition rating, known warranty status, and known repair history within the zone. These attributes update with each inspection cycle, so the zone map is a living document rather than a static diagram.

Drain and penetration inventory: Every drain bowl and overflow scupper is numbered and noted on the diagram with current condition. Every penetration group — pipe clusters, equipment curbs, vent clusters — is marked and labeled. For Atlanta buildings with large and complex rooftop mechanical systems, the penetration inventory is often the first coherent record the facility manager has seen of what is actually on the roof.

Photograph indexing: Key photographs from the most recent inspection are indexed to the zone diagram. A condition anomaly in zone 4 references photograph 4-B in the appendix. This makes the inspection report and the zone diagram a single integrated document rather than separate artifacts that have to be cross-referenced manually.

Zone Mapping for Atlanta's Multi-Vintage Buildings

Atlanta's commercial building stock includes a significant inventory of buildings that have had multiple re-roofing events over different eras, often covering different portions of the roof at different times. A 1985 warehouse in the Forest Park industrial district might have the original 1985 BUR on the north half, a 1998 EPDM recover on the south half, and a 2015 TPO replacement on the loading dock canopy. A Perimeter Center office building might have the main roof on third-generation TPO from 2019 while the mechanical penthouse is still on the original modified bitumen from 1991.

For buildings with this kind of multi-vintage complexity, a single-zone map that treats the whole roof as one system is not useful for capital planning or warranty management. The zone map needs to reflect the different vintage sections, their different remaining service lives, their different warranty statuses, and their different maintenance requirements. This is the kind of documentation complexity that only gets resolved when someone sits down and maps the actual system — which often has not happened, because each prior contractor only documented their own scope.

We have produced zone maps for Buckhead Class A buildings where the previous maintenance contractor had a single inspection report that described the entire 80,000 square foot roof as a uniform system when in fact it had four membrane vintages ranging from 1998 to 2019. The zone mapping exercise resolved 15 years of conflicting inspection data into a coherent asset record.

Zone Maps for Warranty and Insurance Documentation

Manufacturer NDL warranties require that warranty claims be documented with a location reference traceable to the installation documentation. A zone map keyed to the manufacturer's closeout inspection photographs is the standard format for this documentation. Without it, warranty claims that involve areas of the roof with overlapping repair history can become genuinely difficult to adjudicate — the manufacturer's inspector is trying to determine whether the leak origin is in the warranted installation area or in a prior repair that falls outside the warranty.

For insurance purposes — property damage claims, storm damage claims — the zone map is the document that allows the adjuster to match the claim description to a physical location, and allows our condition report to locate damage in a way that is unambiguous to a claim reviewer who has never been on the roof. The March 2021 tornado claims cycle across Atlanta's south corridor underscored this: buildings with current zone maps had faster claim resolution because the damage location was unambiguous; buildings with no zone documentation had longer adjustment cycles.

We maintain zone maps in our project records for every Atlanta building we inspect or maintain. When a building changes ownership or property management, we can transfer the zone map — updated to current conditions — to the new owner or manager as part of the asset handoff. For Atlanta commercial real estate transactions, the existence of a current, accurate zone map is a meaningful piece of due diligence documentation that reduces the risk discount a buyer applies to an unknown-condition asset.

Frequently asked questions