Identify how many palings are affected and where they have detached. Refixing may be possible when the boards and rails remain sound. A moving fence section needs a wider assessment rather than simply adding more screws through the visible boards.
A repair may depend on reaching the fixing side of the fence. Explain available access and any neighbour or property-manager permission required. Do not assume entry to another property is included merely because the damaged board faces your garden.
A timber repair and a coating job are separate parts of the scope. Ask whether any finish preparation is included and follow material guidance. Repeated deterioration should prompt a review of exposure and support rather than repeated cosmetic replacement alone.
The agreed service covers suitable local paling reattachment/replacement and compatible fixing review. Exclusions: Post repair (existing intent), major panel/fence replacement, retaining structures, boundary disputes, pool barriers, unstable supports.