Masonry Magazine January 1976 Page. 25
ADVANTAGES OF PREFABRICATION
Prefabrication of masonry offers several advantages over conventional construction methods.
The quality control of prefabricated masonry is generally better than that of conventional masonry. The panels are built in a shop or plant where the materials can be stored under proper conditions and the brick mason has better control of his working environment. The brick mason is not subjected to weather conditions such as rain, snow, extreme heat, or cold. The lighting conditions are better in a shop than on a scaffold. Mortar joints can be controlled more accurately and can be tooled at the proper time. The curing conditions provided are consistent since they are less affected by weather changes.
Panelization on some projects may save construction time. It is possible that on some projects the masonry panels could be built starting as early as ground breaking for the project, thus keeping far enough ahead of the in-place construction work to permit panel erection when needed. In the case of multi-story structures, construction time could be shortened due to panels already being cured when erected. This would allow the construction crews to immediately start erection of the next floor level and could speed construction.
The savings in construction time could provide economies to the building owner. Any time saving would reduce the length of time required for high interest "interim financing". Earlier completion would allow earlier occupancy which, in the case of rental or commercial properties, would allow the owner to have income production start sooner.
DISADVANTAGES OF PREFABRICATION
As with any construction method, prefabrication has inherent disadvantages as well as advantages. Prefabrication of masonry to date has not achieved the economy of construction originally desired. In the present-day construction market (1973) prefabricated masonry costs are approximately the same or a little higher than conventionally laid-in-place masonry on a square foot cost comparison.
The use of prefabricated brick masonry is limited to use with certain types of construction. The designer should be aware of the limitations of prefabricated masonry. The size of brick masonry panels is limited primarily by transportation and erection limitations. Architectural plan layout may in some cases preclude the use of prefabricated brick masonry.
The use of prefabricated masonry is also limited to some degree by its basic materials, brick and mortar. The designer must be aware of the capabilities of brick masonry to withstand loadings as they occur in the structure.
Another disadvantage of prefabricated brick masonry, as in other panel systems, is the absence of adjustment capabilities during the construction process. In-place masonry construction allows the craftsman to build masonry to fit the other elements of the structure by adjusting joint thicknesses over a large area so that it is not noticeable. This is not possible with prefabricated elements. The use of prefabricated elements sometimes requires other crafts or trades to construct to accuracy beyond the standard construction practices of those trades.
STATE OF THE ART
The use of prefabricated brick masonry in construction has become quite widespread. Prefabricated brick panels have some very dramatic and esthetically pleasing applications throughout the U.S. The panels for these projects have been built utilizing the full spectrum of methods as previously outlined. Figures I through 5 show several recent construction projects using prefabricated brick masonry panels. Most of the projects built in the U.S. have used non-loadbearing curtain wall panels. However, some load-bearing panels have been used and panelized brick construction is not limited to curtain wall applications.
The Penn Square Apartments, Denver, Colorado, pictured in Fig. 1 (Michael W. Lombardi, Architect; Gerald Schlegel, Structural Engineer; Loup Miller Construction, General Contractor; Dach Masonry Construction, Inc., Masonry Contractor). This project used over 1100 4-in. thick prefabricated pierced balcony railings. The exterior brick curtain walls of the structure were conventionally laid.
The Townsend Towers, Syracuse, New York, is shown in Fig. 2 (Chloethiel Woodard Smith & Associates, Architects; Severud Associates, Structural Engineers; Paul Construction Co., General Contractor; R. H. Viau Construction Co., Masonry Contractor). The 21-story high-rise used 4-in. thick standard modular unit curtain wall panels.
The Sheraton Inn, Youngstown, Ohio, is shown in Fig. 3 (Ronald S. Senseman. Architect; Joseph Bucheit & Son, General Contractor; Masonry Systems Inc. of Ohio, Masonry Contractor). The 24,000 sq ft of 4-in. thick curtain wall panels cover a steel frame structure.
The Denver Brick & Pipe Co. Plant, Denver, Colorado, is shown in Fig. 4 (Ken R. White Co., Architects and Engineers; N. G. Petry Construction, General and Masonry Contractors). These unusually shaped prefabricated panels give the structure a pleasing appearance. These panels were built, using stacked bond, soldier coursed standard modular units.
The Philadelphia National Bank of Philadelphia, Pa., is shown in Fig. 5 (Ewing Cole Erdman & Eubank, Architects; McCloskey and Co., General Contractor; John B. Kelly Co., Masonry Contractor; H. & L. Royer, Inc., Panel Fabricators). Approximately 1100 C-shaped panels were fabricated for column and spandrel covers for this structure. These 4-in. panels were plant fabricated off-site by a local masonry contractor, using high-bond mortar.
CONCLUSION
The designer must evaluate each project to determine the feasibility and adaptability of prefabrication to that project. Basic questions which he must answer prior to a decision should include, but not necessarily be limited to, the following for each individual project:
1. Is the building layout suitable to prefabrication?
2. Is it desirable to use off-site prefabrication