Record the delay
Does water appear during use, immediately afterwards or later? Describe the pattern and affected area without deliberately recreating damage.
Separate possible routes
Supply connections, wastes, trays and enclosures do different jobs. Testing should distinguish them where possible rather than assuming the hidden supply is responsible.
Check what a repair includes
A plumbing repair is different from a new enclosure, waterproofing or retiling. Agree the supported repair and any separate work.
Explore the relevant service
General information for planning an investigation. The property, instruction and findings determine the appropriate work.