Supply and fit a felt overlay system to effected area of Flat 3 roof area (24 sqr mtrs)
Supply and fit new felt flashings to the effected side of the water tank above Flat 3.
Lance any areas of felt which have blown and are trapping water ready to be resealed around tank room.
Ensure overflow pipe does not allow any water to track back into tank area.
Seal and water tight overflow pipes to water tank room.
Clear site and leave clean and tidy of any debris.