Application of Metal and Plastic Siding

The interlocking joints of the pieces of siding and the accessory items vary with the manufacturer. Before starting, inspect and plan the job in accordance with the manufacturers’s instructions for the material to be applied. Be sure to use the nail recommended to avoid corrosion and stains. Drive the nails firm and snug, but never so tight as to cause waves in the siding. This is very important, I don’t know how many times I have seen brand new beautiful homes have wavy siding, what an eye sore, to say the least.

The general procedure for the application of metal or plastic siding is as follows:

  1. Run a chalk line for the starter strip around the house. Install the starter strip. All nails should be driven so that the head is only slightly flush to the material. Do not drive the nails hard enough to bind the material tightly.
  2. Nail the inside corner posts 12′ on center before the rest of the siding is applied. The bottom of the corner posts should be aligned with the chalk line. The siding later fits into channels on both sides.
  3. Nail the outside corner posts 12′ on center before the siding is applied. Here also, siding fits into channels on the sides. Fill the cavity behind a wide corner post with a backer board or wood strips. To close in the open lower end of a wide corner post, cut a piece of ‘J’ channel to the proper length (about 6 1/8′). Miter it and then nail it to the wall so that the bottom end of the corner post will fit over it.
  4. Attach the door and window trim along the sides of the doors and windows. The gables are also trimmed with this accessory. The same trim is used at the base of a wall intersecting a sloping roof, as on a breezeway.
  5. Install undersill and general purpose trim under windows and at the tops of walls against soffit moldings, furring where necessary to preserve alignment with the adjacent panels. This may also be used inverted to lock lower cut edges of siding courses which are located above the level of the starter strip, such as at porch floors and cellar bulkheads.
  6. Place the first siding panel in the starter strip and lock it securely. Backerboards, if used, are dropped into place. Nail the panel and install succeeding courses similarly. Nails must never be driven so tightly as to cause distortion of the siding. Allowance should be made for expansion and contraction by leaving a 1/4′ space at joints, channels, and corner posts. On the end to be overlapped, cuts should be made according to the manufacturer’s instructions. For best appearance, overlap the siding away from areas of greatest traffic. Stagger end laps a minimum of 24′ and in such a way that one is not directly above another unless separated by three courses. The end of the uncut panel should lap over the end of the cut panel.
  7. Cut and fit the siding as necessary around windows and doors.
  8. Attach window head flashing or widow and door trim above the window and doors as application reaches these levels, furring out where necessary for alignment.
  9. Trim the last course of siding to fit under the eaves. Install undersill and general purpose trim, furring where necessary to maintain proper panel angle. Engage the top of the panel with undersill and general purpose trim and lock at lower edge of panel as usual. Nail to secure when necessary.
  10. To complete the gables, install widows and door trim above the window at the gable ends. Cut the siding to the proper angle and install.
  11. Caulk where required.
  12. Finish by washing down the siding to remove fingerprints and soil. Clean up all scrap material around the house.