This Masonry Designers' Guide (MDG) is intended to assist those involved in the design, construction, and regulation of masonry structures. The Guide was prepared to help users apply the provisions of Building Code Requirements for Masonry Structures (ACI 530-92/ASCE 5-92/TMS 402-92) and Specifications for Masonry Structures (ACI 530.1-92/ASCE 6-92/TMS 602-92). Emphasis in the MDG is on application of the two documents. Background information on the development of the Code and Specifications provisions is not emphasized. For such information the reader is referred to Commentary on Building Code Requirements for Masonry Structures (ACI 530-92/ASCE 5-92/TMS 402-92) and Commentary on Specifications for Masonry Structures (ACI 530.1/ASCE 6-92/TMS 602-92). One section of the handbook covers materials and testing. Another section on construction addresses quality assurance, quality control. and hot and cold weather construction. The section on design, which comprises the bulk of the book, shows how to apply masonry code provisions to the structural design of beams, walls, columns, and pilasters. It also covers different types of construction (multiwythe composite and noncomposite, single wythe, unreinforced and reinforced) based on the structural analysis of three typical types of masonry buildings: a one-story shopping center, a one-story gymnasium, and a four-story hotel. There are 87 design examples.