Common low-slope roof concerns
- Ponding water, clogged drains, scuppers, or gutters
- Open seams, punctures, shrinkage, blisters, ridges, or surface deterioration
- Failed wall, parapet, curb, edge, or penetration flashings
- Leaks near HVAC, vents, drains, skylights, or roof access
- Wet insulation, recurring repairs, or unknown prior roof layers
Repair or restoration
Localized repair may be reasonable when the surrounding assembly is dry and serviceable. A coating or restoration system requires compatible and adequately prepared conditions; it should not be used merely to cover widespread wet insulation or failing attachment.
Replacement planning
- Core cuts, moisture survey, or other investigation when needed
- Tear-off versus recover decisions and code limits
- Insulation value, taper, drainage, cover board, membrane, fastening, and flashings
- Occupied-building protection, equipment coordination, phased work, and temporary water control
- Manufacturer and contractor warranty requirements
Maintenance records
Keep inspection dates, photographs, leak locations, repair history, warranties, drawings, rooftop-work records, drain cleaning, and invoices. These records improve diagnosis and capital planning.
Four different decisions, often presented as one
A moisture survey is the instrument that separates them. Commonly infrared, nuclear or capacitance, it identifies suspected wet areas within the assembly, and test cuts confirm the findings. Ask about method, limits, interpretation and whether cuts were taken — a survey is evidence, not a verdict.
The reason this matters commercially is that wet insulation does not dry. It stays wet, loses thermal value, corrodes deck, and expands the eventual replacement scope every season it remains. A coating applied over it conceals the problem while adding cost and complicating the eventual replacement.
| Option | When it applies | What rules it out |
|---|---|---|
| Repair | Defined failures in an otherwise serviceable assembly | Widespread wet insulation or failed attachment |
| Recover | A sound existing assembly with layer count and code allowing | Existing layers at the limit; wet or compressed insulation |
| Coating | A sound substrate needing maintenance and reflectivity | Wet insulation, failed attachment, incompatible membrane |
| Replace | Wet assembly, end of life, or drainage that must be corrected | Nothing — but it is the most disruptive and costly |
Why leaks are hard to locate on a low-slope roof
Water that gets beneath a membrane — particularly on a mechanically fastened assembly — can travel a long way from its entry point before finding a path through the deck. The interior evidence therefore says very little about where the breach is, and a proposal that promises a precise diagnosis before investigation is overselling.
This is also why a leak log is the cheapest cost control available on a commercial roof. Recording location, date, weather conditions and what was done turns a vague argument about roof condition into a specific one, and it reveals recurring locations, roof-traffic patterns and drainage problems that individual callouts never surface.
- A dated leak log with location, weather and action taken
- Records of every trade that goes on the roof, especially HVAC
- Drain, scupper and overflow condition before and after leaf fall
- Seam, flashing, curb and edge-metal condition documented over time
- Warranty terms, and what rooftop activity could void them
What a replacement proposal must resolve
Drainage deserves particular attention, because a new membrane laid over an assembly that never drained will pond exactly as the old one did. Tapered insulation, additional drains, or crickets between drains are how the geometry actually changes, and they belong in the conversation explicitly rather than being inherited by default.
- How many membrane layers already exist and what the code position is
- Whether a moisture survey was done, by what method, and whether test cuts confirmed it
- Substrate, attachment method, insulation type and taper for the new assembly
- Whether a cover board is included — an easy place to reduce a bid price
- Whether drainage is being corrected or inherited
- Which warranty is offered: manufacturer system, material only, or contractor workmanship
Published August 12, 2026 and last reviewed August 16, 2026 by Greater Burlington Roofing. General roofing information; an on-site inspection is required for property-specific recommendations.