A concrete-tiled roof may have replaced an older slate roof
Blackpool Council notes that some roofs have been re-covered over the years while many original slate roofs survive.
Parapets and high-level gutters can be difficult to inspect from the street
From street level it can be difficult to see hidden outlets or defects behind a roof edge.
Changing an older roof covering may need consent
In conservation areas, replacing slate with a different material or adding rooflights can affect the appearance of the building and may need consent before work starts.