By Jay Fox
Exterior insulation and finish systems (EIFS) have become more common within the last ten years as more owners have become interested in energy efficiency and optimizing the performance of their buildings. At their most basic, EIFS can be thought of as enhanced cladding systems that shed water, allow drainage, and improve thermal performance by integrating a layer of continuous insulation into the exterior wall system, thereby minimizing thermal bridging.
In North America, the insulation contained within EIFS has typically been expanded polystyrene (EPS) or extruded polystyrene (XPS). These options are also available in Europe, but European EIFS have also used high-density stone wool. More recently, ROCKWOOL has begun working with EIFS manufacturers in North America to incorporate their stone wool products into EIFS that are available in the U.S. and Canada. As explained during a recent Component Spotlight featuring ROCKWOOL, this is a boon to builders in North America, especially if they are operating in states or provinces where building and energy codes are more stringent and fire resilient wall assemblies are in higher demand.
Stone wool’s fire resilience is well known. It can maintain performance levels even at temperatures of up to 1200°F (650°C) and is capable of withstanding temperatures exceeding 1000⁰ C (1832⁰ F), so it naturally lends itself for use as a fire blocking material within exterior wall systems. This makes it an ideal building material in areas that are adjacent to undeveloped spaces (e.g., the wildland-urban interface [WUI]) and densely populated cities where buildings are separated by limited or even no lot lines. Beyond that, there are several advantages to using stone wool over other types of insulation. Stone wool:
Is vapor permeable and dries easily
Maintains consistent thermal performance
Has exceptional acoustic performance
Does not expand, warp, or contract
Is UV stable
Cannot serve as a food source for mold, mildew, or pests like termites