uPVC 405mm Soffit Board (10mm General Purpose) 2.5m - Dark Grey Dimensions Length: 2.5m. Width: 405mm. Thickness: 10mm. Material: uPVC. Guarantee: 10 years. Description The plain fascia system is a clean, modern style which includes the 10mm thick fascia board and a full range of accessories to ensure a neat and professional installation. The plain fascia system comes in a wide range of solid colours, woodgrain finishes and fascia widths.