Vinyl siding

Vinyl siding is plastic exterior siding for a house, used for decoration and weatherproofing, imitating wood clapboard, and used instead of other materials such as aluminum or fiber cement siding. It is an engineered product, manufactured primarily from polyvinyl chloride (PVC) resin. In the UK and New Zealand a similar material is known as uPVC weatherboarding.

Approximately 80 percent of its weight is PVC resin, with the remaining 20 percent being ingredients that impart color, opacity, gloss, impact resistance, flexibility, and durability. It is the most commonly installed exterior cladding for residential construction in the United States and Canada.

Vinyl siding was introduced to the exterior market in the late 1950s as a replacement for aluminum siding. It was first produced by an independently owned manufacturing plant called Crane Plastics in Columbus, Ohio. The process was originally done through mono-extrusion, a process of forming the profile from a single material into the desired shape and size. At that time, blending of colors was done manually.

This original process made it difficult to produce and install a consistent, quality product. Beginning in the 1970s, the industry changed its formulation to improve the product's production speed, impact resistance, and range of colors.

In the following decade, vinyl siding grew steadily in popularity in large part due to its durability, versatility, and ease of maintenance. However, in many European countries, for instance Germany, vinyl (PVC) is rarely used or phased out because of its negative environmental profile.

Today, vinyl siding is manufactured by co-extrusion. Two layers of PVC are laid down in a continuous extrusion process; the top layer is weatherable and durable material, which comprises up to 25% of the siding thickness. This capstock can include about 10% titanium dioxide, depending on the color, which is a pigment and provides resistance to breakdown from UV light. Vinyl siding, like anything that is exposed to the sun, will inevitably fade over time, but the fade rate is a lot slower with vinyl than most other claddings. Most manufacturers offer 50 year warranties that their products will only fade a little over that period of time. In the past darker colors tended to fade more than lighter ones, but advancements in technology and materials this is no longer the case. With these advancements darker colors like dark reds or blues show very little change in color, but they do cost a little more. The lower layer, known as substrate, is typically about 15% ground limestone (which is largely calcium carbonate). The limestone reduces cost, and also balances the titanium dioxide, keeping both extrusion streams equally fluid during manufacturing. A small quantity of tin mercaptan or butadiene is added as a stabilizer to chemically tie up any hydrochloric acid that is released into the PVC material as the siding ages. Lubricants are also added to aid in the manufacturing process.

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