Feature All images courtesy CertainTeed Fibre Cement Siding 101 By Allison Barlaz, MBA, and Neil J. Sexton, AIA or light commercial or multi-family projects, brick, stone, or wood exterior claddings have time-honoured visual appeal. However, these natural materials each have drawbacks. Brick and stone cladding can be expensive and engineered wood siding can suffer from performance problems. Solid wood siding requires significant maintenance. Without regular upkeep, wood-based products can become brittle, split, swell, and deteriorate over time. Fibre cement siding emulates the traditional look of wood, but with considerably lower maintenance expenses. It is extremely durable, dimensionally stable, and resistant to damage from everyday impact. While fibre cement must be primed and painted or stained like wood, the material’s adherence properties reduce the frequency of re-coating. The only additional maintenance required is simple cleaning—the exterior may be washed with a common garden hose to remove dirt and debris as necessary. All wood-based products absorb water when exposed to moisture, causing expansion that places continuous stress on the material over the years. More importantly, the subsequent growth of internal mould and fungus in wood siding can foster decay that goes unnoticed until the damage requires expensive replacement. In contrast, fibre F cement neither rots nor experiences this type of swelling and warping. The material resists the damaging effects of salt spray and ultraviolet (UV) rays and does not succumb to the stress of freeze-thaw cycles. Another attribute that sometimes goes unnoticed is the material’s non-combustibility—an important feature for projects in areas where fire hazards are a concern. (This is discussed later in the article.) Due to its superior durability and resistance to damage from extreme weather conditions, the material can be used in virtually any climate. However, design/construction professionals must first understand fibre cement’s physical properties, testing methods, and how it fits into Canadian building codes. Manufacturing fibre cement Ensuring the quality of the finished fibre cement siding panel begins with the raw materials. All components are thoroughly examined and tested as part of an ongoing quality assurance process. Most manufacturers subject their products to different tests to ensure that Canadian Construction Materials Centre (CCMC), Canadian Standards Association (CSA), ASTM, and other standards are met. (These tests will be explored later in this article.) 68 January 2010 Construction Canada CC_JanFeb10.indd 68 12/22/09 11:57:14 AM