Then you just slide the piece of siding in until your cut mark on the siding aligns with the kerf you want and make the cut.
How to make a jig for cutting vinyl siding.
Hold the piece in place and screw the jig to the 1 by 2 from the other side using three 1 1 2 inch drywall screws.
Run the saw through once to create a kerf in the channel.
The jig is pretty simple it requires two pieces of plywood can be same thickness a couple boards of the same thickness for risers two boards to use as runners and a handful of screws.
Place the narrow edge against the middle of the jig so it runs from side to side on the same side as the 1 by 3 piece that overlaps the jig end.
Put a piece of 1x1 on one of the 1x4s to act as a saw guide.
The risers need to be taller than the profile of the material you re cutting.
Attach the riser boards to a large piece of plywood.
This piece is the handle.
Accommodates full length sidings and soffits.