The answer to 'flat roof curling' is that the most common causes are poor installation, exposure to UV rays, and age. Symptoms include the roof material lifting or pulling away from the edges or seams. Solutions can range from simple DIY repairs to full roof replacement, depending on the extent of the damage.
If the curling is mild and localized, you may be able to repair it yourself by re-adhering the material or applying a sealant. However, for widespread or severe curling, it's best to call in a professional roofing contractor to evaluate the roof and provide the appropriate repair or replacement recommendations.