Roof decking is the boarding or sheathing layer forming part of the underlying roof construction. Different sheet or board materials may be present. The term identifies a component, not its condition, load capacity or suitability for a proposed new finish.
In an existing roof, decking may be largely concealed by internal finishes, insulation or other layers. A photograph of roof tiles therefore cannot show it completely. Available drawings help prepare an investigation question but need to correspond to the actual arrangement.
Ask whether decking will be assessed when a proposal relies on retaining it. Record which sections were visible and which remain uncertain. A material name without that context is insufficient for drawing conclusions about the appropriate repair or renewal scope.
Worth asking
Frequently asked questions
Can decking be approved from a roof photograph?
Not completely. Concealed components and properties require appropriate assessment.
Is decking the same as an underlay membrane?
No. They are different components with different positions or roles in the assembly.