Masonry Magazine April 1997 Page. 49
Inspection
The code requires inspection, but the degree of required inspection is not stipulated. The proposed inspection guidelines take care of this by requiring a level of inspection based on the importance of the structure and on the method of design (engineered or empirical). Structures are divided into three groups: Non essential structures including agricultural facilities, certain temporary structures, minor storage facilities empirically designed; non-essential engineered structures like movie theaters, small business; and essential engineered structures such as, fire stations, police stations, hospitals, etc. Three levels of inspection are proposed:
Level 1
These requirements would be the least stringent, and would verify that the masonry construction complies with the plans and specifications. This level of inspection would apply to empirically designed masonry, glass unit masonry and veneer for non-essential facilities.
Level 2
Periodic-type inspection would be required for engineered masonry of non-essential facilities and empirically designed masonry, glass unit masonry, and veneer of essential facilities. Key inspection items would be assurance that required reinforcing steel, anchors, ties, and connectors are in place and that appropriate grouting procedures are used.
Level 3
Full-time inspection would be required for engineered masonry of essential facilities to verify compliance of proportions of site mixed mortar and grout, placement of masonry units and construction of mortar joints, placement of reinforcement and connectors, grout space and placement of grout.
Masonry Foundations of Chapter 18
The masonry foundation wall provisions will not be found in Chapter 21, but instead will follow the common code format and will be found in Chapter 18 of the IBC. This section is based on the 1996 BOCA National Building Code foundation wall provisions. In these the designer can either design according to AC1530/ASCE 5/TMS 402 or use the prescriptive table contained in the section. As described above, these tables specify minimum thickness for unreinforced masonry based on wall height and soil loading. For reinforced masonry, reinforcing steel size and spacing is specified for an eight inch nominal wall thickness for certain wall heights and soil loading.
Masonry Fire Resistance of Chapter 7
The fire safety subcommittee of the IBC is responsible for developing the fire safety related chapters. These chapters deal with fire resistance and fire protection. To date, MACS has focused on the provisions contained in Chapter 7, Fire Resistant Materials and Construction. In this Chapter are provisions that allows the fire resistance ratings of materials or assemblies to be established by calculations as an alternate to full-scale fire tests. The masonry industry supports this alternative to these full-scale test with published equivalent thickness tables and the fire ratings in hours for each equivalent thickness.
The Chapter 7 provisions were developed by a side-by-side comparison of provisions in the BOCA National Building Code (BNBC), Standard Building Code (SBC), the Uniform Building Code (UBC), and provisions developed by CABO Board of the Coordination of the Model Codes (BCMC). This matrix was reviewed item-by-item and the IBC subcommittee agreed which language they thought appropriate.
MACS has been monitoring this process very carefully, and through industry personnel and consultants has influenced the first draft of this chapter. The Chapter contains prescriptive details of fireresistance rated assemblies based on Table 7-B of the UBC. This table lists the fire resistance ratings consistent with masonry industry published values. Also, it allows equivalent thickness increases when block cells are fill with approved materials. Chapter 7 also contains a section on calculated fire resistance based on the current values listed in Section 709 of the SBC. In the future, MACS will propose to reference a consensus standard, ACI 216, currently under review and expected to be published by mid 1997, for provision on calculated fire resistance ratings. MACS also has a representative on the subcommittee that developed the ACI 216 standard.
Summary
The ICC is planning to promulgate to a single set of building codes. This is evident based on the commitment of staff personnel from the three model building code organizations. As a result of their commitment, the process to develop these codes is on schedule. The first working draft is expected by June 1997. Once the working draft is released for public review, many of the masonry design and construction provisions discussed will be subject to change.
The building code environment is changing and as pointed out, building codes do effect market share. Building codes can open up new markets and, without a vigilant position, close certain markets for building systems The masonry industry through the Masonry Alliance for Codes and Standards is participating in this changing code environment. MACS continues to review, revise, suggest changes in order to put forth masonry provision based on sound thinking and technical accuracy. We will continue to maintain a vigilant position through the development, adoption, and enforcement of the building codes.
Editors Note: Jeff Greenwald is the Codes Engineer for the National Concrete Masonry Association. His duties and responsibilities include monitoring the code development process for all the model codes and representing NCMA at the respective code development hearings. Mr. Greenwald also submits code changes that reflect the interests of the masonry industry. Additionally, Mr. Greenwald aids in the development of technical publications on the design of masonry structures.