While color fade and rigidity were legitimate concerns in the past, manufacturers have improved their vinyl products to address these problems. Today’s vinyl siding comes in a variety of designs and styles to fit every taste and is available in dozens of color choices.
Before you reclad your house in vinyl, look at other houses on your street and ask local realtors how vinyl affects home values in your neighborhood.
The Top Layer
The top layer of vinyl siding is a weatherable cap stock that contains titanium dioxide to offer color and protection from breakdown caused by UV radiation. This layer also has a little tin mercaptan to help prevent color fading.
This coating also includes ingredients to give it good scratch resistance. One of the biggest issues with vinyl in the past was its color fading from sun exposure, but this is less of a problem today thanks to improved production techniques and finish options.
When installing vinyl, Tom says it’s important not to nail it too tightly or the flange on the bottom of each panel can break (Fig. 15). It’s also important to ensure that the nails penetrate at least 1 1/4″ into framing and furring.
To keep his vinyl looking good, Tom uses a mild solution of vinegar and water to wash it. He avoids using a power washer, which can drive moisture behind the panels and cause them to rot or mold.
The Bottom Layer
The second layer, or substrate, takes up about three-quarters of the total thickness and consists of 15% ground limestone (calcium carbonate). This layer balances the titanium dioxide that is incorporated in the top layer to keep both layers fluid during the manufacturing process. It also contains lubricants and small amounts of tin mercaptan to help stabilize the vinyl as it ages.
This layer is bonded to the top layer by extrusion, which pushes both layers of PVC together through a die of the desired cross-section profile. The co-extrusion process makes the substrate more resilient than a single-layer piece of siding and increases its strength.
The co-extrusion process is energy efficient and requires far less raw material than other manufacturing processes. The process also releases significantly fewer greenhouse gases and carcinogenic compounds than do similar processes for other claddings. This means that vinyl is a greener option for your home.
The Extrusion Process
Originally, vinyl siding was prone to cracking and warping, but engineering innovations in the 1970s made it more durable. Today, it holds up well against rain, wind, heat and cold, resists dents and corrodes far less than aluminum or steel siding can.
Vinyl is also a popular choice because it comes in an array of colors and textures. It is very versatile and can help a homeowner manifest their dream home. Vinyl doesn’t need a lot of maintenance and has better insulation properties than most wood and metal siding.
One of the drawbacks to vinyl is that it can fade over time from sun exposure, but most manufacturers offer 50 year warranties on their product to counteract color fading. Vinyl is also not as energy-efficient as wood, but many manufacturers now offer insulated vinyl that can prevent heat loss and keep the house cool in summer. The insulating property is a result of a layer of foam adhered to the vinyl.
From a distance vinyl siding looks like conventional wood siding. But at corners, windows and doors, wall-mounted utility equipment, and other details, it quickly becomes apparent that a home has been clad with a plastic product.
To avoid this, installers install tar paper or housewrap behind the vinyl and punch weep holes in the bottom edge to let water escape. They also flash the windows and doors, directing rain back out through flanges or casing.
When installing vinyl siding, it’s important to leave the end gaps and utility channel clearances recommended by the manufacturer so that the product can move with temperature changes. And it’s a good idea to “hang” rather than nail the product, which means to loosely fasten each piece of vinyl siding to its mounting blocks and to leave the head of each nail out 1/8 inch or so proud of the trim to allow sideways movement as well. This technique will help prevent ugly buckling of the course of vinyl siding when it warms and contracts.