What is a MACS? No, it has nothing to do with fast food.
Behind the scenes of national product and trade associations lies an obscure, but dedicated and successful, group championing code development initiatives and preserving markets for the masonry industry. This organization is the Masonry Alliance for Codes and Standards (MACS). It is supported by funding and active participation from national, regional, state, and local masonry industry associations, producers, contractors, suppliers, and installers.
MACS works through a committee structure formatted in a way that addresses multiple technical issues and areas in the codes and standards arena affecting masonry. It is constantly multi-tasking to accomplish these goals.
The majority of the work and investment is dedicated to structural, fire safety, and energy conservation change proposals related to the I-codes, such as the International Building Code, and referenced standards, such as ASHRAE 90.1. In addition, there is work on issues related to fireplaces and chimneys, masonry veneers, and items that may be unique to residential construction.
MACS is comprised of individuals representing national, state, and local industry associations and groups. Much of its technical work is with and through code consultants and researchers. They develop strategies, tactics, and substantiation to influence the development of code provisions that may provide building occupants a comfortable, productive, safe, and secure environment. These efforts are also intended to increase safety for emergency responders and minimize the depletion of community, personal, and business resources in the event of a disaster.
To accomplish its mission, MACS often works with groups outside the masonry industry. This approach is typical when code change proposals will impact more than just masonry. Sometimes these groups are even outside the construction industry because the proposals may have a community impact or affect specific occupancies.
Often, the activities of MACS are behind the scenes and preclude the organization from gaining recognition for its efforts in the industry.What has MACS done for you lately?
A lot! MACS has preserved your markets. While this article does not permit an exhaustive listing or explanation of everything MACS has done, the following discussion highlights several major interest areas.
Energy Conservation: The MACS energy consultant, working with the PCA representative on ASHRAE 90.l, had their appeals on Addendum Z upheld. Addendum Z contains provisions requiring air barriers for building envelopes. They were found by some to be arbitrary, technically unfounded, and not economically justified. The appeal prevented these requirements from advancing to publication and being placed in the standard.
If the provisions had advanced as written, single-wythe masonry in any jurisdiction that adopted the new ASHRAE 90.1 Energy Standard for New Buildings Except Low-rise Residential Buildings would be required to apply coatings and single-wythe construction would be priced out of the marketplace.
While efforts to require air barriers will not disappear, they will continue to be addressed in the ASHRAE standards and I-codes. The successful appeal has given the masonry industry additional time to develop appropriate test methods and design and construction procedures to effectively and affordably reduce airflow through single-wythe masonry.
In addition, the appeal should lead to refinement of the provisions to ensure, to the best degree possible, correct technical substantiation and economic justification.
Other high priority energy issues include continued efforts to retain and improve thermal mass benefits, and to ensure that thermal resistance requirements for opaque walls are cost effective.
Fire Protection: MACS supported efforts in the International Building Code (IBC) that resulted in the minimum number of exit stairways in high-rise buildings (those more than 420 ft) being increased from a minimum of two to three. Adding an additional stairway increases the total interior egress width of exit stairway shafts that may be used for evacuation downward while emergency responders on the same stairways are traversing upward. This change significantly improves life safety and the ability to control and extinguish fires.
Stairway enclosures are required to be fire-rated construction. While such enclosures may not all be constructed of masonry, the product is an option to satisfy this requirement. However, like any code provision, once changes are included, they do not necessarily stay there.
The extra stairway provision is being challenged. Stairways use space and reduce the rental or useable space per floor. Challenges are being made in this code cycle to eliminate the additional stairway.
Other high priority fire safety code issues for masonry include retaining appropriate building height and area requirements, and minimizing trade-offs of passive fire protection for fire sprinklers.
Structural Design: One of the biggest issues that affects the structural design of masonry being addressed by MACS is splice lengths in walls, which are a problem when the minimum amount calculated is larger than the height of the wall. Temporary relief was provided via code changes submitted by MACS to modify the IBC while the issue was being addressed in the structural design standard (MSJC).
Other key structural issues address anchorage, maximum percentages of steel reinforcement, and grouting.
Wind Issues: Sometimes the potential benefits of MACS code efforts are somewhat obscure. For example, MACS is supporting a code change that prohibits the use of gravel ballast for roofs exposed to high winds, thus requiring other alternatives for these systems. While one alternative may be an adhered single-ply roof in lieu of a ballasted single-ply roof, another option would be the use of interconnected masonry roof pavers.