Final answer:
When a flat roof has water stains, it indicates signs of previous leaks, pointing to water damage. These stains necessitate immediate inspection to prevent further issues and costly repairs.
Step-by-step explanation:
When a flat roof has water stains, these are signs of previous leaks
. Water stains typically appear as dark or rusty patches on the ceiling underneath the flat roof, and they indicate that water has at one point penetrated the roof's surface and caused damage.
This could have been due to a variety of reasons such as heavy rainfall, melting snow, or poor drainage. Spotting these signs of water damage early is crucial to prevent further structural issues and potentially costly repairs.
It is important to address any water stains promptly by inspecting the roof for current leaks or vulnerabilities.