Replacing a damaged panel
To replace a cracked or badly stained panel of vinyl siding, buy from a siding dealer a zipper tool along with the replacement panel. Repair weathered siding with a panel from an inconspicuous part of the house and replace that panel with the new one.
Replace a section at least 4 feet long. Use a combination square to mark cutting lines on the damaged panel. Let an edge fall along an existing joint if one is close. Work the zipper tool under the edge of the panel above the damaged one. Pull down on it and draw it along the edge to unlock the panel. Prop the unlocked panel open with wood blocks. Remove the nails in the damaged panel’s top edge. Cut out the damaged area with in snips.
Cut the replacement panel 1 1/2 inches longer than the opening to allow for a 3/4-inch overlap at each end. Slip the panel under one adjacent panel’s edge and overlap the other. Follow the existing pattern of overlaps. Make sure the panel’s bottom edge locks in place. Secure the panel’s upper edge with aluminum nails at 16-inch intervals. Center each nail in an oval slot. Stop hammering when the head is about 1/32 inch from being flush. Relock the panel above with the zipper tool.