Vinyl Siding – The Good, the Bad and the Ugly


Vinyl siding as been around since the 1960s, and it is growing in popularity each year. It was originally designed to be a re-cover siding, intended to be installed over the top of an existing water-tight siding material as a means of quickly enhancing the exterior of a house. Unfortunately, the easy application and relatively low cost enticed builders into using this material as a primary waterproofing material. At this time, nearly 30% of new homes now have vinyl siding.

Over the years, roofers have witnessed the effects vinyl siding has had on the building industry. Multiple times every year, roofers are asked to investigate roof leaks, only to discover that the source of the leaks are a nearby vinyl-clad wall! Many homeowners and contractors are discovering that their initial cost savings by installing vinyl will ultimately cost them many times more through water damage to their homes. How can this possibly be the case? Let’s take a look at the three “faces” of vinyl siding.

The Good

Vinyl siding is a contractor’s dream material. It installs quickly and it is much less expensive than other siding materials on the market, resulting in both cheaper installation and material costs. With vinyl siding, no painting is required. This means a contractor can avoid painting-related scheduling delays that are often caused by cold and wet winters. Vinyl siding is available in a great variety of colors, and the newer generations of vinyl are less prone to fading. It is also available in a variety of faux wood grain finishes to mimic natural materials. With all of these positive attributes, it sounds like the ideal siding material, right?

The Bad

Vinyl siding is not a watertight covering for a variety of reasons. The material expands and contracts with temperature fluctuations. The result of this is that vinyl siding cannot be caulked and sealed at wall penetrations like windows and doors. Wind-driven water can be forced into these gaps around the unsealed window and door trims, as well as into the overlapping ends of the siding pieces. In addition, the installation of vinyl siding requires the use of several pre-made trim pieces. These trim pieces have limitations in their applications, and they cannot possibly be bent, trimmed, and formed to meet every conceivable installation requirement. The Washington Post explains some of the problems that vinyl-clad homes face these days:

“…for most people, the real surprise is that vinyl siding leaks — a lot. The industry puts a positive spin on this issue, describing the siding as a ‘supplemental rain screen’ that works by ‘reducing the amount of water that reaches the underlying weather-resistant barrier.’ The Vinyl Siding Institute says, ‘vinyl siding is designed to allow the material underneath to breathe; therefore it is not a watertight covering’ — which is to say, it leaks. Water enters through overlapped joints, but mainly at open-sided edge trim. Anticipating this, manufacturers provide weep holes along the bottom edges of clapboard panels. You can’t stop water infiltration by caulking because, unlike stationary trim seams in wood or masonry, vinyl has to move freely.”

Since vinyl siding itself is not waterproof, the building is ultimately protected by a water-resistant underlayment (house wrap), with additional protection provided by peal and stick waterproofing membranes that are used at high-risk areas such as window and door openings. Unfortunately, the water-resistant underlayment is punctured by several hundred siding nails. Also, any installation mistakes with the underlayment, or the way the underlayment is integrated with the peal and stick window/door membranes, will ultimately result in leaks.

The number of lawsuits being filed against contractors and vinyl siding manufacturers has been on the incline for many years now. Many condominiums and housing developments have experienced lawsuits involving vinyl siding installations. Raynproof Roofing is called quite often by people throughout Seattle and King County to investigate phantom “roof” leaks, only to discover that the problem is the result of the siding.

The Ugly

Vinyl siding does not increase the value of one’s home, and in some cases, can actually diminish its value if the home has historic value or is located in a nicer neighborhood with more traditional siding material such as wood, brick or stucco.

When used as a recovering material, many of the defects of the base siding will be reflected in the vinyl covering. In addition, using vinyl as a recover material “thickens” the wall and many window and door trims actually get buried so you start to lose some of your home’s character.

Squeaking and even clattering has been heard when the wind blows strongly against vinyl-clad homes. This is due to the way vinyl must be installed leaving the width of a dime between the nail head and the vinyl panel to allow for movement.

The other “ugly” reality that homeowners sometimes forget to consider is that the color of the vinyl will be the color of their home forever — or until they decide to reside it with something else. Yes, it could be painted, but then you lose the low maintenance quality that it provided in the first place. Vinyl siding can also be easily damaged either by windblown debris, lawnmower debris, ladders or anything else that is harder than the vinyl. Once damaged, the entire panel must be replaced and new replacement panels will not be an exact match since vinyl does tend to fade within five years or so.


As you can see, there is a lot to consider when facing vinyl siding and the possible effects it has on your home. If you do own a vinyl-clad home, be sure to check it out on a regular basis and in a variety of weather conditions, because trapped water behind the vinyl siding can cause all kinds of problems, including structural damage, mold, mildew and insect infestations.

If you suspect water intrusion into the interior of your house, have a professional siding company inspect your home. You might also consider having a thermal imaging analysis done to identify the extent of any leaks and/or damage. Finally, don’t assume that all water leaks are due to a roof leak.


Source by David Buckles