How to Select Vinyl Siding
Vinyl siding has been an important part of the home building and remodeling industry for decades, yet there are strong feelings for and against the material. Supporters state that it never needs painting, while its detractors insist that houses should never be covered with anything but real wood.
Vinyl siding was introduced in the late 1950s as a substitute for aluminum siding. But it suffered early on when problems arose due to cracking, fading, and buckling of the new material. Modifications to the formula and installation techniques have improved its performance and made it an acceptable choice for builders and homeowners alike.
Currently vinyl siding accounts for 32 percent of the U.S. siding market for new homes.
A mid-grade vinyl costs about $1.60 per square foot to install, not including the trim pieces, while the installed price of mid-grade cedar clapboard, excluding trim and paint, is about $4.00. There are premium vinyl siding panels that cost about the same as cedar, but the installed cost is still lower.
Vinyl Siding Material
Vinyl is a polymer formed between ethylene gas and chlorine, which produces a powder called vinyl resin. When it's melted and mixed with different additives, the resulting compound can be rigid as pipe, flexible, or durable.
New vinyl siding has other key additives that impart flexibility and resistance to UV degradation. Some manufacturers will tout their product as 100 percent virgin vinyl, but most siding is made with a core of re-melted vinyl top-coated with new virgin material.
Typically, vinyl siding is extruded through a die, but for panels with deeper patterns and crisper edges, panels must be molded from polypropylene, which is a more expensive plastic. Molded panels are typically no more than 4 feet long, while vinyl extrusions can be virtually any length, but are sold in boxes of 10-foot or 12-foot lengths.
Most vinyl siding material is thin with no backing support. The thinnest siding that meets code is .035 inch thick. Premium siding can be .044 to .048 inch, and a few manufacturers sell .055-inch siding. The thicker sidings tend to be stiffer, and therefore more resistant to sagging, but stiffness depends on other characteristics as well.
Panels with a folded-over, doubled nailing hem and a relatively deep profile tend to be stiffer as well as panels with more than 2 clapboards in the face. Although claims are made that thicker siding is also more impact resistant than thin siding, test results suggest that it has more to do with its chemical makeup, which, unfortunately, is not available to consumers who want to compare products.
Thinner siding panels can be ripped off during high winds. The manufacturer's warranty should give you a good indication of the product's ability to handle severe weather. Some vinyl siding even complies with the 146-miles-per-hour wind code in hurricane-prone Miami, Florida. Wolverine Millennium, comes with a “won't-blow-off” warranty, and its literature states that it will withstand 180-mph winds, when nailed properly.
Several manufacturers are trying to make their vinyl siding stronger and more damage resistant. Heavy gauge vinyl, additional bends, and new types of nailing hems are a few of the ways that they make their products stronger.
Sliding Fiberglass Rod locks adjacent panels together and improves stiffness
Flexible fabric nailing hem allows for tighter nailing
A folded nailing hem doubles the thickness (left) of the vinyl so windstorms are less likely to rip off the siding.
Insulated Vinyl Siding panels – Some vinyl siding panels can have R-Values of up to R-5. Insulated panels can withstand high wind speeds and they can handle up to four times the impact compared to that of regular siding. The insulation also provides a good acoustic insulator and will reduce high frequency noises and wind sounds by up to 45%
Some panels can be made to look like cedar shakes.
While wood siding is fastened tightly to the house, vinyl siding hangs from nails driven through horizontal slots at the top of a panel's nailing strip, called a hem. Vinyl siding is not designed to be nailed tightly to the structure as it needs to expand or contract as the temperature changes: A 12-foot length of vinyl siding can expand as much as 5/8 inch with seasonal temperature swings. If nailed tight to a wall, it can buckle on hot days.
Buckled Vinyl Siding
Nail heads shouldn't contact the hem, but should be left about 1/32 inch above it. Conversely, if nailed too loosely the panels will rattle whenever the wind blows and can cause the bottom locking strip to separate from the panel beneath it.
Due to its design vinyl is less likely than wood to trap moisture since there are tiny weep holes in the butts of the panels and due to the fact that the panels are hung loosely to allow air movement behind the siding.
Vinyl's tendency to move means that panels can't be butted tight to trim, either. During installation, a gap of about 1/4 inch, or 3/8 inch in temperatures below 40°F, at the end of panel courses. Where siding panels end at corners and door and window openings a trim piece called J-channel conceals the gap.
In addition to J-channels, one characteristic that distinguishes vinyl from other siding is its overlaps. While lengths of wood or cement siding meet in a butt joint, vinyl panels must be overlapped by about 1 inch wherever they meet, resulting in noticeable vertical lines. The thicker the vinyl, the more obvious the overlap. Since most vinyl siding panels are molded to mimic double or triple widths of clapboards to reduce installation time it also makes panel overlaps more visible. When installing vinyl siding orient overlaps away from dominant views, for example, by running the siding from a back corner to a front corner. On the front of the house, panels should be installed so seams are least visible to someone approaching the front door.
To keep vinyl siding looking its best, it should be washed periodically to remove any mold, mildew, dirt, and chalky oxidation that collects on the surface. Use a soft-bristle brush and a bucket with a mix of vinegar and water (1 part vinegar to 3 parts water). The Vinyl Siding Institute suggests mixing 1/3 cup laundry detergent, 2/3 cup powdered household cleaner, 1 quart liquid laundry bleach, and 1 gallon water if the vinegar and water fails to clean the siding. Work from the bottom up and don’t use a power washer on their siding. The high-pressure equipment is likely to drive water behind the panels.
All vinyl siding will fade somewhat. After 10 to 15 years, the change can be significant. When that happens, or if you simply want to change its color, vinyl can be painted. Check with the manufacturer first as many companies void the warranty if siding is painted. Wash the siding first, and use latex paint, which will flex with the vinyl's movement. Avoid using dark colors that will absorb more heat than lighter ones and can cause panels to expand too much and buckle. Limit your color selection to lighter colors.
Vinyl Siding Institute