Design Considerations

Section Contents:

Product characteristics. A standard vinyl siding panel has three main components:

  • A nail hem at the top of the panel where nailing slots are located.
  • The face, which is the area of the siding that will be visible once the installation is complete.
  • The buttlock, located on the bottom edge of the panel, which locks onto the previously installed panel.

The panels interlock to create an aesthetically pleasing and durable exterior for a home or building. When installed correctly, vinyl siding systems protect the structure of a building from the elements and water penetration. Accessories such as J-channels, corner posts and soffit are aesthetic, functional or both, hiding seams, providing an architectural accent to the siding or enclosing eaves or overhangs. Vinyl siding panels are manufactured in a range of lengths and widths. The average panel length is 12' to 12-1/2', but some panels can range from 14' to 16' or can even be as long as 40'. The typical width of panels is between 6-1/2" to 10".

Although many architects and specifiers think of vinyl siding as an option only in residential projects, it can actually be incorporated into a wide variety of light commercial and institutional designs as well. Assisted living facilities, retail buildings, churches, schools, libraries and office parks striving for a residential "feel" are a perfect fit for vinyl siding and accessories.

Today's vinyl siding is available in a multitude of colors with many embossed surface textures. Architectural scallops, shutters and detailed accessories such as corner posts and fascia are also available to coordinate easily with any design. Vinyl siding can be used to create a classic colonial style or a post-modern look, and virtually anything in between.

Today's vinyl siding products have lifetime warranties backed by more than 35 years of outdoor exposure. These guarantees are often transferable between owners of a home or building.

Since vinyl siding and accessories will melt when exposed to a significant source of flame or heat, home and building owners should take care to keep sources of fire - such as outdoor grills - and easily combustible materials - such as dry leaves, mulch and trash - away from vinyl siding. However, rigid vinyl siding has a relatively high ignition temperature (736 F) as compared to other materials like wood, cotton and other plastics. This means that even when exposed to an open flame source, vinyl will resist ignition much longer than most materials, which could serve to slow or even stop the spread of a fire.

If vinyl siding catches fire, it has a much lower flame spread rate than some comparable siding products - two and a half times lower than that of cedar siding and three times lower than hardboard siding. This relatively low flame spread rate slows the growth of a fire, allowing occupants more time to escape. Wall structures with installed vinyl siding have been tested according to the American Society for Testing and Materials (ASTM) standard ASTM E119 and found to have fire endurance ratings comparable to walls without vinyl siding installed. In other words, vinyl siding does not degrade the fire performance of a typical wall; in some fire situations, it could improve a wall's fire performance.

Technical data. The standard for technical performance of vinyl siding products is ASTM D3679, Standard Specification for Rigid Polyvinyl Chloride (PVC) Siding. This standard has established requirements and test methods for the materials, dimensions, warp, shrinkage, impact strength, expansion, appearance and windload resistance. For more information, see "Selection and Specification Guidance."

Installation. Proper installation is critical to the appearance and long life of vinyl siding. Certainly, vinyl siding products may vary, but there are some general guidelines to follow for any vinyl siding installation job. A siding installer should always contact the siding manufacturer to determine whether there are specialized installation instructions for that product. A complete vinyl siding installation manual is available on the Vinyl Siding Institute's (VSI's) website at, or by calling VSI's Vinyl Siding Information Center at (888) FOR-VSI-1.

Because of vinyl's expansion and contraction properties, one of the key challenges during vinyl siding installation is to allow room for the siding to move in changing weather conditions. The following tips are important to keep in mind when installing vinyl siding, but for more detailed instructions and estimating information, consult VSI's installation manual.

  • When transporting and storing vinyl siding at a job site, be sure to keep the cartons dry, rest them on a flat surface and provide support for the entire length of the carton. Do not stack more than two boxes on top of one another.
  • Be sure that installed panels can move freely from side to side, allowing for expansion and contraction of the panel.
  • When installing a siding panel, push up from the bottom until the lock is fully engaged with the piece below it. Without stretching the panel, reach up and nail it in place.
  • Place nails or other fasteners in the center of the nailing slot.
  • Do not force the panels up or down when fastening in position. Allow them to hang without strain.
  • Do not drive the head of the nail tightly against the siding nail hem. Allow 1/32" (about the thickness of a dime) clearance between the fastener head and the siding panel. Drive nails straight and level to prevent distortion and buckling of the panel.
  • Leave a minimum of 1/4" clearance at all openings and stops to allow for normal expansion and contraction. When installing in temperatures below 40 F, increase minimum clearance to 3/8".
  • Do not caulk the panels where they meet the receiver of inside corners, outside corners or J-trim. Do not caulk the overlap joints.
  • Do not face-nail or staple through siding. Vinyl siding expands and contracts with outside temperature changes. Face-nailing can result in ripples in the siding.
  • When re-siding, adding furring strips to a wall or removing uneven siding may be necessary.
  • In new construction (for the best aesthetics), 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.

Cost. Nearly every architect, specifier and building professional faces the challenge of creating quality buildings or homes on a budget. Vinyl siding and accessories help meet the cost containment demands of the home or building owner. One recent study comparing vinyl siding to brick, aluminum siding and wood sidings in the residential market in terms of initial installed costs and 20-year maintenance costs found vinyl offered a cost savings of up to 60 percent compared to these alternatives. (include bar graph from Marquest study) R.S. Means 1999 data indicate that the installed cost of vinyl siding is among the lowest of the various siding options. At an estimated $2.02 per square foot installed, vinyl siding is less costly than fiber cement ($2.46 to $2.69 per square foot), wood siding ($2.37 to $5.30 per square foot), aluminum siding ($2.09 to $4.00 per square foot) and steel siding ($2.53 to $3.24 per square foot).

Maintenance requirements. Because color is blended throughout the product during the manufacturing process, vinyl siding and accessories do not need to be painted or stained and will maintain a uniform color throughout their life. The vinyl siding industry's efforts have been focused on minimizing color change within the first two years after installation. Research has shown that change after that period is negligible.

From time to time, building managers and homeowners will need to wash their vinyl siding to eliminate dirt and dust, mold and mildew, grass and other stains. For tougher stains, vinyl siding can be cleaned with a soft cloth or soft-bristled brush (recommended for textured surfaces). Avoid abrasive cleaning products or cleaners containing organic solvents or other aggressive ingredients. Below are some suggested common cleaning products that can be used to remove stains from vinyl siding.

Cleaners for Stain Removal of Vinyl Siding


Bubble Gum Fantastic®, Murphy Oil Soap®, solution of vinegar (30%) and water (70%), and Windex®
Crayon Lestoil®
DAP (Oil-based caulk) Fantastic®
Felt-tip Pen Fantastic®, water-based cleaners Grass Fantastic®, Lysol®, Murphy Oil Soap®, Windex®
Lipstick Fantastic®, Murphy Oil Soap®
Lithium Grease Fantastic®, Lestoil®, Murphy Oil Soap®, Windex®
Mold and Mildew Fantastic®, solution of vinegar (30%) and water (70%), and Windex®
Motor Oil Fantastic®, Lysol®, Murphy Oil Soap®, Windex®
Oil Soft Scrub®
Paint Brillo® Pad, Soft Scrub®
Pencil Soft Scrub®
Rust Fantastic®, Murphy Oil Soap®, Windex®
Tar Soft Scrub®
Top Soil Fantastic®, Lestoil®, Murphy Oil Soap®
*cleaners listed in alphabetical order

If a home or building owner wants a new look but does not wish to replace the siding, vinyl siding can be painted with the appropriate pre-treatment. However, doing so may void the product warranty and joints will show differently with expansion and contraction.