Title: THERMAL BRIDGES IN WALL CONSTRUCTION - NCMA
Headings: THERMAL BRIDGES IN WALL CONSTRUCTION
THERMAL BRIDGES IN WALL CONSTRUCTION
INTRODUCTION
THERMAL BRIDGING
Causes
Effects
Requirements
SINGLE WYTHE MASONRY WALL
CONCRETE MASONRY CAVITY WALL
MASONRY VENEER WITH STEEL STUD BACKUP
SLAB EDGE & PERIMETER BEAM
MASONRY PARAPET
References

Content: CONCRETE MASONRY CAVITY WALL
In masonry cavity walls, insulation is typically placed between the two wythes of masonry, as shown in Figure 1. This provides a continuous layer of insulation, which minimizes the effects of thermal bridging (note that some references term the space between furring or studs as a “cavity,” which differs from a masonry cavity wall). Because the wall ties are isolated from the interior, the interior surface of the wall remains at a temperature close to the building’s interior temperature. The interior finish material is not likely to be damaged due to moisture condensation, and occupant comfort is not likely to be affected. As with horizontal joint reinforcement in single wythe construction, the type, size, and spacing of the ties will affect the potential impact on energy use. Figure 1—Insulated Masonry Cavity Wall
MASONRY VENEER WITH STEEL STUD BACKUP
Figure 2 shows a cross section of a typical concrete masonry veneer over a steel stud backup. Steel studs act as strong thermal bridges in an insulated wall system. Almost 1,000 times more heat flows through the steel than through mineral fiber insulation of the same thickness and area. The steel stud allows heat to bypass the insulation, and greatly reduces the insulation’s effectiveness. Just as for concrete masonry webs, the thermal bridging through steel studs must be accounted for.