Tuesday, 14 April 2015

A Lesson on Vinyl Siding


The Benefits of Vinyl Siding
There are few subjects in the whole realm of residential and commercial construction products that draw battle lines as sharply as vinyl siding. Proponents harp on the fact that it never needs painting, while its detractors insist that houses should never be covered with anything but real wood. 

As a building material, vinyl siding is relatively new — it was introduced in the late 1950s as a substitute for aluminum siding. However, its reputation was tarnished in the early days when it cracked, faded, buckled, and sagged due to lack of industry knowledge on how to perfect the product. Thankfully, ongoing changes in the product's chemistry and installation techniques have improved its performance and furthered its acceptance by builders and homeowners.

Today, a mid-grade vinyl costs about $1.60 per square foot to install, not including the necessary trim pieces; while the installed price of mid-grade cedar clapboard, exclusive of trim and paint, is about 2.5 times higher. For many people, price isn't the issue at all; the real seduction of plastic siding is reduced maintenance.

All Plastic Siding is Not the Same
New, so-called virgin vinyl siding has a greater complement of the key additives that impart flexibility and resistance to UV degradation. Some manufacturers will boast their product as 100 percent virgin, but most siding is made with a core of remelted vinyl top-coated with virgin material. Rap on a vinyl-sided wall with your knuckles, and it will flex and sound hollow. That's because, in most cases, only a relatively small area of a vinyl panel is actually resting against the sheathing. 

A thin panel, or one without support, is more likely to sag over time. However, 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 than others, as do those with narrow “clapboards”: The more bends the better. 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, less-stiff sidings can also be sucked off a house when high winds blow. Reading the manufacturer's warranty should give you a good indication of the product's ability to handle heavy weather.

While wood siding is fastened tightly to the house, vinyl siding literally hangs from nails driven through horizontal slots at the top of a panel's nailing hem. The reason for the loose nailing has to do with the vinyl's need to expand or contract as the temperature changes.
One characteristic that distinguishes vinyl from other siding is its overlaps. While lengths of wood siding meet in an unobtrusive butt, vinyl panels must be overlapped by about 1 inch wherever they meet, resulting in telltale vertical lines. The thicker the vinyl, the more obvious the overlap. Compounding the problem, most vinyl siding panels are molded to represent double or even triple widths of clapboards. This slashes installation time dramatically, but it also makes panel overlaps even more visible. A good installer will 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.

Every quality vinyl siding job starts with the contractor. Don't hesitate to ask potential installers for their certifications — most of the large manufacturers certify installers in proper installation techniques — and for the names of satisfied customers.

Not Entirely Maintenance Free

To keep vinyl siding looking its best, it should be washed periodically to remove the mold, mildew, dirt, and chalky oxidation that collects on the surface. Avoid using high-pressure equipment such as powerwashers to clean your siding as it can compromise the integrity of the product. Thankfully, repairing a damaged panel is simple. With a zip tool and a flick of the wrist, you can simply unhook it from the ones above and below, then pull out the nails. A new panel can then be snapped in place, nailed, and rehooked. The biggest problem is matching the replacement to the surrounding pieces, which will undoubtedly have faded.

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, as self-defeating as it may seem. Wash the siding first, and use latex paint, which will flex with the vinyl's movement. But don't count on changing a pale-yellow house to hunter green; dark colors absorb more heat than lighter ones and can cause panels to expand too much and buckle.

Going with Vinyl

Much of what appeals to us about older historic houses, apart from their architectural style, is the graceful moldings, well-proportioned trim, subtle shadow lines, even the slight irregularities in the spacing of the siding — testaments to the skills of this country's housewrights. But in countless slipshod re-siding jobs, where vinyl is slapped up over the existing shingles or clapboards, these details have been obliterated, making the facades of handsome gingerbread houses as plain as sheet cakes.

For those contemplating having a house re-sided, find a contractor who specializes in old-house work not just in vinyl siding, pending that all the architectural details remain in place. A proper paint job may make more sense, if that's the case. Sometimes, re-siding jobs are sold as a way to “tighten up” the house and reduce energy bills. The installers simply nail up a layer of foil-faced foam before the vinyl goes up. The final word: If you have any doubts about its effects, don't put vinyl siding on your old house. 

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