When it comes to the thermal barrier, ci systems on the exterior of a building deliver the greatest R-value and overall energy performance. The American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE) defines ci as “continuous across all structural members without thermal bridges other than fasteners and service openings.”1 Thermally insulating the exterior of the wall structure with ci wraps the building in a thick, well-insulated, protective blanket, and eliminates thermal bridging, which keeps the wall structure warm and dry. Using ci on the outside of the wall maintains the temperature of the building wall structure above the dew point, effectively dealing with the potential for condensation caused by water vapor diffusion.
Advancements in material science now deliver thermal barriers for the exterior wall, providing even greater fire protection. Mineral wool insulation, which is noncombustible, inorganic, and mold-retardant can resist fire and temperatures in excess of 1093 C (2000 F). When mineral wool serves as the thermal barrier in a fully engineered assembly, it also allows the vapor barrier to do its job without creating additional traps for moisture in the wall cavity.
Cladding: the power of possibilities
Using a ci exterior system on the wall assembly broadens the range of possibilities for the exterior facade cladding. Rather than being limited to delivering a textured, stucco-looking aesthetic, architects and designers can paint with a broad brush. They can combine the traditional looks of brick, stone, concrete, and stucco with the modern appeal of metal, wood, and tile. For instance, architects may choose to create the look of brick or wood over a ci exterior system by employing resin-cast shapes. This approach maintains the timeless look of traditional brick or wood without having construction crews lay brick and mortar or cut and ship lumber. It creates an authentic-looking facade, capitalizing on the latest material science. Even the discerning eye has difficulty determining if the material used is not traditional brick or wood.
Resin-cast bricks and wood can be made to match traditional textures and colors while creating unique looks. Compared to their predecessors, resin-cast brick and wood require little maintenance. They will not warp, crack, or chip, and are not prone to efflorescence. For increased UV resistance and hydrophobicity, they can be enhanced with a wide variety of coatings as well.
The possibilities do not end with resin-cast shapes; architects can also achieve the look of brick, wood, concrete, stone, metal, and other materials using trowel-applied acrylic finishes or a variety of other exterior coatings. The result is a more durable surface delivering the desired aesthetic.
