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: Causes
Thermal bridging is most often caused by improper installation or by material choice/building design. An example of improper installation leading to thermal bridging is gaps in insulation, which allow heat to escape around the insulation and may also allow air leakage. For this reason, insulation materials should be installed without gaps at the floor, ceiling, roof, walls, framing, or between the adjacent insulation materials. Further, insulation materials should be installed so that they remain in position over time. Although thermal bridging is primarily associated with conduction heat transfer (heat flow through solid materials), thermal bridging effects can be magnified by heat and moisture transfer due to air movement, particularly when warm, moist air enters the wall. For this reason, buildings with typically high interior humidity levels, such as swimming pools, spas, and cold storage facilities, are particularly susceptible to moisture damage. Proper installation of vapor and air retarders can greatly reduce moisture damage caused by thermal bridges. Concrete masonry construction does not necessarily require separate vapor or air retarders: check local building codes for requirements. Minimizing moisture leakage will also alleviate thermal bridging due to air leakage for two reasons: