Steel framed buildings have many advantages, but the major negative is the thermal bridging losses through the steel webs. More stringent energy codes are forcing architects and designers to devise new designs to not only meet present requirements, but to strive further to achieve higher LEEDS ratings, and ultimately strive toward net zero buildings.
External/continuous insulation is now commonly being used to achieve these improved values. However, there are challenges for supporting cladding loads directly through the external/continuous insulation. As a result, sub framing must be added in the form of metal hat tracks or Z-girts. If these are oriented vertically, there is still significant thermal bridging transmission. By applying these sub components horizontally, bridging losses are most effectively reduced.
However, there are challenges in installing claddings such as stucco to horizontal members. Lathing standards require that lath be applied with the long dimension at right angles to the supports. To meet this requirement, the lath must therefore be applied vertically.
Structa Wire Corp has innovated a system with their Structa Mega lath that meets all the structural and performance requirements for this application. This installation option is now described and included in their ER 2017 Evaluation Report.
The benefits and advantages of this system are:
- Mega lath can span 24 inch framing centers. This minimizes the added metal and thermal bridging.
- Meets higher energy standards
- External/continuous insulation thicknesses can be increased
- Can be applied over cavity space to incorporate rainscreen designs
- Since product is in rolls, length of lath can be tailored to building specifics without unnecessary laps and waste
- Meets structural attachment requirements and building codes
- Fully recognized through ER approval
- Simplified constructability with viable solutions
- Proven in field with several projects
- Reduced cracking