Soffit, fascia What is a soffit? A fascia?In simple terms, the definition of fascia is a flat band that goes around the roofing surface right under your rooftop. Fascias wrap around the roof surface that is perpendicular to the earth. A soffit is installed in the under-side of the rafters/overhang.PBA HOME SIDING! Our metal soffit and fascias are designed to complement your rafters and provide added energy efficiency. Fascia Covering wood fascia with aluminum provides a superior alternative to painting. Fascia is an important element in your roof structure and soffits, and deciding how to protect it is more important than just deciding which color to use. Fascia boards can be covered using pre-formed aluminum fascia or field-formed aluminum trim coil. And it completely covers the fascia board from the drip edge to the soffit. Professional installers will tell you that properly-installed aluminum fascia looks better than painted wood from the first day of installation, and looks better over the years.