A good question! Fascias are typically PVC boards which your house gutters are mounted onto. They face outward and normally run along the whole length of the roof.
Soffits are fitted adjacent to the underside of the fascia boards and face downward. Not all fascias will have soffits, as they are only required when the edge of the roof overhangs the house.
We are also able to clean most other PVC surfaces, such as cladding and panelling. If you have any questions regarding the cleaning you require, please feel free to ask.