Categories of Commercial Wall Assemblies

Montgomery, Texas construction professional William “Bill” Starkey served as the CEO of Starkey Construction, a high-quality builder of custom luxury homes, for more than 35 years. William Starkey is also interested in green building practices, such as improved thermal performance of buildings and how certain wall assemblies, including mass walls, barrier walls, and hollow walls, may aid in this.

In commercial buildings, moisture is handled differently by the three primary wall assemblies: mass walls, barrier walls, and hollow walls. In mass walls, the bulk of the wall components is used to prevent moisture intrusion. Although there are exceptions, such as holes inside double-wythe brick walls, there are often no additional mechanisms in place to prevent moisture from entering the structure of those materials fail.

The only moisture barriers in barrier walls are the cladding material and joint seals. Precast concrete panels and external insulation and finish systems (EIFS) are barrier walls. Early EIFS installations demonstrated the difficulties with these systems, as moisture leakage was common due to fractures in the outer layer, earning them a bad reputation. New EIFS systems, on the other hand, frequently include drainage.

Cavity walls, which vary from mass and barrier walls in that they have an air gap below the sheathing, are the most common. Moisture that gets past the cladding is prevented by a weather barrier and drains away from the structure, and moisture is not pushed into the assembly since the air pressure is equalized in many of these systems.