- 1). Measure the width of the underside of the fascia with a tape measure and record the measurement. Lay the soffit on a flat surface. Run a tape measure along the soffit and mark the recorded length. Most widths are around 24 inches. Measure the length of the house in feet. Write down the measurement so the proper amount of soffit can be cut.
- 2). Draw a small line with a black marker every 24 inches along the entire 12-foot piece of fascia. Line up a T-square at each mark and draw a straight line across the soffit. This will allow for an easier cut. Mark all of the rest of the pieces of soffit necessary to cover the entire house.
- 3). Line up a pair of tin snips at the first black mark and cut straight along the mark. Tin snips cut like scissors. Repeat the process for all of the other lines on the soffit. Cut the remaining pieces of soffit in the same manner.
- 4). Slide the first 2-foot piece of soffit into the J-channel beginning at either side of the house. Slip it into the channels by hand and hammer small finishing nails into the soffit. Position the first nail at the beginning of the soffit. Hammer it into the soffit and through the lip of the J-channel. Insert three nails on each side of the soffit.
- 5). Insert the second piece of soffit next to the first, and install it just like the first was installed. Continue down the house until all of the soffit is installed. Inspect the area and verify all the pieces are secure in place. Add finishing nails, if necessary.
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