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Exterior Claddings

For beauty, durability, and value
By: VSI - (Vinyl Siding Institute)


Today's challenging economic times have Canadian design/construction professionals searching for ways to create diverse designs and boost curb appeal, all while on tight budgets. Building material selection-including the specification of an exterior wall cladding-plays a major role in meeting these requirements.

Vinyl siding's value and affordability have long made it popular for low-rise residential, hospitality and light commercial projects. With the advent of an increasingly diverse selection of profiles, colours, textures, architectural trim, and accessories, the material is increasingly also selected for its beauty and creative design possibilities. New perceptions regarding its durability further contribute to overall value.

Vinyl siding has the lowest total installed cost of virtually any exterior cladding, and produces little waste when installed. Further, since only modest amounts of energy are required for manufacturing and transporting the lightweight material, it is also considered to contribute less to global warming over its lifecycle.

Additionally, vinyl siding is installed without labour-intensive priming and caulking, and never requires painting. With respect to maintenance, the cladding may need to be rinsed occasionally with mild soap and water, but this is usually the only work required to keep it looking as good as when it was originally installed.


Durability and weathering
Using advanced design principles and careful material selection. Vinyl siding is engineered for durability. It provides optimum stiffness, stability and resistance to wind while maintaining its light weight and ease of installation. With the ability to withstand high. winds and a composition that resists heat, cold, and moisture, vinyl siding retains its beauty over time. Further, the material's expected service life continues to increase as improvements are made to colour retention, impact resistance, and other key durability aspects.

The National Building Code of Canada (NBC,) has recognized vinyl siding as an acceptable cladding for years- The requirements for vinyl siding are contained in several parts of IBC depending on the application. Section 9.27.I3 serv.,-s as the base for both the material standard and its installation. The siding must comply with Canadian General Standards Board (CAN/CGSB) 41.24, Rigid Siding, Soffits, and Fascia, which includes requirements specific to the Canadian climate.

The standard requires vinyl siding meet product performance criteria for attributes including:
- impact resistance;
- thermal expansion;
- shrinkage;
- dimensional stability and surface distortion;
- gloss;
- colour consistency;
- weatherability; and
- wind resistance.

Some tests are additionally applied at cold temperatures in anticipation of environmental conditions found throughout the country. For example, under the performance requirements for product listings of the Canadian Construction Materials Centre (CCMC), vinyl siding is required to be impact-tested at both 23 and 0 C (73 and 32 F) to ensure performance at lower temperatures. (1)

Most vinyl siding manuftcturers have their products approved through CCMC, which offers a national evaluation service for all types of building materials. CCMC evaluations are supported by the latest technical research and expertise and are based on NBC requirements or those of provincial and territorial codes. (Once approved, the CCMC-evaluated products used in commercial and residential buildings will have their approved listing number on a label on the package.)

Going further, the Vinyl Siding Institute's (VSI's) product certification program marks products meeting or exceeding quality consistent with ASTM D 3679, Standard Specification for Rigid PVC Siding it requires materials withstand pressures equivalent to winds of at least 177 km/h (110 mph). Nevertheless, most vinyl siding qualifies for installation in even higher wind zones; several manufacturers offer products rated for pressures equivalent to 306-km/h (190-mph) winds-such materials could be ideal for the Maritimes and other areas facing the threat of hurricanes.

Vinyl siding is also used extensively in a variety of climates, withstanding summer heat in excess of 38 C (100 F) and extended periods of winter cold lower than - l8 C (-1 F). While there are no specific temperature limitations to the use of vinyl siding, manufacturers should be consulted for any product's specific limits or advice on the most appropriate material for the application.

With respect to rain. vinyl siding is not a water-resistive barrier in itself, but it is commonly part of a holistic system consisting of the exterior cladding, the flashed wall openings and penetrations, and the water-restrictive barrier material and sheathing. Effective exterior wa.li assemblies will shed the water initially, control moisture flow by capillary and diffusion action, and minimize absorption into the wall structure. The level of water resistance required is determined by the ,applicable building code, the structure, and the climate.

Vinyl siding provides a supplemental rain screen that reduces the amount of water reaching the underlying barrier. In marine climates like coastal British Columbia or the Maritimes, rain-screening techniques have become mandatory to keep moisture from penetrating the building envelope. Vinyl siding can be one of the best moisture management claddings from a building science perspective. The material's performance in this regard allows vinyl to be exempt from current rain-screening techniques in British Columbia according to the province's Building Policy Branch under the Office of Housing and Construction Standards policy number F,07-02.

For specific product applications and recommendations, builders should reference VSI's Vinyl Siding lnstallation Manual, which is based in part on ASTM D 4756, Standard Practice for Installation of Rigid PVC Siding and Soffit, and the manufacturer's installation manual. Any product used as part of a water-resistive barrier system must be installed to meet the requirements of the applicable local building code. Additionally, some provinces and territories have special requirements depending on the climate and installation techniques unique in that area. For example, the Siding Contractors Association of Alberta (SCAA) has published a supplemental installation manual to address specific code requirements in that province.' (2)


Design flexibility
Designers use vinyl siding to achieve myriad attractive looks inspired by various periods of architecture ranging from Romantic to eclectic. Via architectural trim and accessories, designers can easily add details that accomplish the vision or period look they want.

There are three dominant vinyl siding profiles: clapboard, Dutchlap, and beaded. These traditional profiles are available in single, double, and triple courses (i.e. rows) and at varying heights (i.e. reveals). This versatility allows builders and designers to mix and match profiles within a development to deliver greater diversity. Additional design options include accents in shapes with various self-explanatory names such as:
- scallop;
- round;
- half-round;
- fish-scale;
- half-cove;
- octagon; and
- hexagon.

In some historical styles (e.g. Queen Anne and ltalianate), diverse vinyl siding shapes are used on gable facades or tower walls. Board-and-batten siding is another profile option employed in whole house applications (e.g. Folk Victorian) or as an accent on gables in the Craftsman style.

Additionally, designers are able to select textures (e.g. deep wood grain or smooth to replicate sanded, sealed, and painted wood). Specialty vinyl siding profiles also include shakes and shingles and are available in a variety of textures to simulate authentic cedar shakes. Hand split, rough-split, and rough-sawn are among the available assortment. To have the look of wood without the often-associated concerns of rotting, swelling, warping, chipping, peeling, or fading is a major factor in selecting vinyl siding.


Spectrum of colours and surfaces
Equally important as the type of profiles are the colours available. Designers using vinyl siding have an almost unlimited choice of options, more than any other pre-finished cladding. Although original pastel and neutral hues are still available, darker options such as bold earth tones (including barn reds, and hunter and sage greens) are being specified with increasing frequency. These and other shades such as heritage blue, country green, Victorian grey, or natural cedar help designers add curb appeal. There are currently nearly 350 vinyl siding hues certified for colour retention.

When Kara Landry wanted to build her Kara's Urban Day Spa on the main thoroughfare in Dartmouth, Nova Scotia, she wanted something that would stand apart from other buildings on the block. Working with installer Fred Hutchinson (Sarty Siding and Windows), she selected vinyl siding as the exterior cladding.

They chose a deep red for its warm, attention-getting properties - the double 102-mm (4-in.) traditional clapboard siding was accented with white fluted corner posts, and a 63.5-mm (2.5-in.) white decorative trim was used around windows and doors. To further create visual interest, they added vinyl mantels with keystones over the windows and doors; white sof6t, facia, and gutters were included to continue the dramatic look.

Further west, vinyl siding is being incorporated into a residential development in Mississauga, Ont. For its Garden Villas of Thomas, Great Gulf Homes envisioned streetscapes with a 'neighbourhood feel' among the l3 blocks of units. To help achieve this, the individual units within the blocks feature brick masonry along with a variety of vinyl siding profiles, including traditional clapboard, fish-scale shapes, shakes, and vinyl soffit.

"While architects often specify wood, shake, or brick exclusively as an exterior cladding, they find they can have the desired look by choosing vinyl siding, and enjoy the benefits of low maintenance, durability and affordability,"says Mike Foerster, owner of Klondike Vinyl Building Products, the company installing the siding for the project. "We used many different vinyl siding products together to achieve more originality and with a wide choice of colours from varying shades of white to deep reds, blues and greens, we had the ability to deliver a result that matched the vision of the architects and designers."

Foerster says within the last two years, newer profiles such as rough-sawn vinyl shakes have been introduced in the Toronto area and are being accepted because their texture so closely replicates authentic cedar shakes. With its more affordable price tag, designers are using vinyl shakes to keep overall costs down without losing beauty.


Vinyl - Over the Lifecycle
Polyvinyl chloride (PVC) starts with two simple building blocks: Chlorine (57 per cent) from common salt-one of Earth's most common compounds-and ethylene (43 per cent) from natural gas. Siding made from this material has scored well on tough environmental measures through all lifecycle stages.

Lifecycle analysis (LCA) is a technique evaluating the environmental impact of a material from raw material acquisition through manufacturing, transportation, installation, use, and waste management. In almost ail lifecycle stages for environmental and economic performance, vinyl siding outperformed most of the other exterior cladding when analyzed using Building for Environmental and Economic Sustainability (BEES) software.

BEES is established per International Organization for Standardization (ISO) I 4O40, Environmental Management Life Cycle Assessment Principles and Framework the criteria for the development of Iifecycle assessment and ASTM standards. This software is recognized by green building professionals as a useful tool for selecting environmentally preferable products.

With respect to energy efficiency, opting for insulated vinyl siding can boost the exterior wall's R-value, as well as improve impact resistance and help replicate the feel of solid wood plank. Many manufacturers now offer this product variation to meet growing consumer demand for energy-saving products.

Two types of insulating siding are available. One style features a foam plastic backer fused to the vinyl siding for a one-piece siding and insulation system. The other common product type has the foam backer custom-contoured for a snug fit during installation. Both types are available in a variety of profiles and reveals.


Conclusion
Improvements in colour retention, impact resistance, and other key durability aspects help ensure the enduring performance of vinyl siding. Through economic times may be tough, the material continues to be a solid exterior cladding choice for builders, architects, and owners wanting an affordable design that also offers beauty, durability sustainability, and long-term value for new construction projects.

Read the PDF - Construction Canada


(1) See "CCMC 1996-08-30 Evaluation Listings for Vinyl Siding MasterFormat Section 07 463."(2) For more information, visit www.scaa.ca .