cause permanent damage to the siding panel. If you need to lengthen the nail slot, you can do so with a nail-slot punch. Drive fasteners in straight. Nailing at an angle will distort siding panels and cause buckling. Be careful not to stretch panels. Apply slight upward pressure until the lock is fully engaged, then secure allowing panels to move freely without strain. Use fasteners long enough to penetrate a minimum of 3/4" into the nailable base. In residing, furring or removal of uneven original siding may be necessary. In new construction, avoid the use of green lumber as the underlayment. Keep in mind that siding can only be as straight and stable as what lies under it. Materials Sheathing/Backerboard -- Vinyl siding should be applied over a sheathing that provides a smooth, flat surface. Consult local building codes for sheathing requirements. Vinyl siding should never be applied directly to open studs without sheathing. As an alternative, installation of specific types of contoured foam underlayment for various styles of vinyl siding are available. Weather Resistant Barrier -- Vinyl siding should be installed over a continuous weather resistant barrier to stop the intrusion of incidental water. Consult your local building code for requirements in your area. Flashing -- Code-compliant flashing should be integrated with the weather resistant barrier and applied around windows, doors, and other openings. Flashing should also be applied to inside and outside corners, and the intersection of walls and roofing to prevent water infiltration. Preparing to Install Preparing