A concrete roof deck is part of the supporting assembly, not a substitute for a specified waterproof roof. Before installing new roofing, the project team must determine what kind of concrete assembly is present and how the proposed system's substrate requirements will be assessed. Appearance alone is not a complete preparation standard.
Identify the deck before selecting the system
Collect original drawings, renovation records and any documentation of previous roof removals. Ask the contractor to distinguish structural concrete from insulating fill and other layers above it. GAF's discussion of concrete roof decks describes several different categories, reinforcing that “concrete roof” is not a sufficiently precise scope description.
If the existing assembly is uncertain, ask what investigation will resolve it and when the results will influence the bid. Avoid choosing an adhesive or insulation scheme first and leaving substrate identification until the material arrives. The order of those decisions affects how meaningful the quoted scope can be.
Make moisture evaluation a defined task
Ask the designer and roofing manufacturer which evaluation method and acceptance criteria apply to the proposed assembly. The owner should receive the written conclusion and understand who makes it. Do not substitute an unrelated floor-covering limit, a generic handheld reading or an arbitrary drying period for system-specific direction.
For example, a project with newly placed repair concrete may need a different sequence from one involving an existing exposed deck. Ask how repaired areas are identified and what must happen before they receive the next layer. Record how weather exposure during the work will be handled as well.
Agree on the response to unsuitable conditions
The contract should explain who is notified if the deck does not meet the specified requirements. Include responsibility for temporary protection, additional preparation and revised scheduling. This prevents an uncertain surface condition from becoming an improvised decision made solely to keep a crew moving.
At completion, retain the assessment records, product instructions and approved changes. Photographs should show identifiable locations, especially where repairs or preparation differ from the general roof area. A useful closeout file links those records to the roof assembly actually installed.
Perkins' commercial roofing overview explains the project starting point, and its flat-roof guide provides broader low-slope context. Bring available drawings and a timeline of leaks or repairs. Those facts help the project team define a concrete-deck scope with explicit preparation responsibilities rather than relying on an incomplete surface description.
Manufacturer references: GAF: Concrete roof deck types.