Masonry Magazine November 1963 Page. 5
The Contemporary Bearing Wall
construction techniques
During 1964 a major effort of the Structural Clay Products Institute and its regional offices will be the promotion of masonry bearing wall construction. The effort is based upon extensive research by the SCPI Engineering and Technology Department, and given impetus by the contemporary desire of designers for fresh and exciting architectural forms. Masonry bearing wall construction appeals especially to those decision-makers in the building field who want to combine the beautiful and the practical. The following series of articles have been prepared by SCPI and do not necessarily represent the editorial viewpoint of this publication.
PREFACE
this series of articles is not intended to be a complete all-inclusive "manual" of wall-bearing construction techniques for the mason contractor. It is merely an introductory discussion of some of the important items we both the mason contractor and general contractor must consider in planning and scheduling the construction of wall-bearing buildings particularly multi-story structures if the economies inherent in such systems are to be realized. The re-emergence of clay masonry as an engineered structural building material will, no doubt, require certain changes in the general operations of the mason contractor and the general contractor alike. We hope, therefore, that the discussions that follow will stimulate interest of both groups in seeking better and more efficient methods of building structures in which the structural properties of clay masonry are utilized to the best advantage.
INTRODUCTION
With the return of wall-bearing clay masonry to multi-building construction, new techniques and methods for the operations of the mason contractor and the general contractor are necessary. To analyze wall-bearing construction techniques, it is necessary first to compare it with the presently generally accepted method of building multi-story buildings - the skeleton frame system. The actual differences are in the structural frame either concrete or steel. The frame work is erected story by story and, in many cases, the floor is set and poured as the frame goes up.
If the skeleton frame is steel, it goes up quite rapidly and then things slow down again as the floors are poured and then the exterior panel walls are erected. Once these exterior walls are in place, the other trades begin their work. The advantage of the quick erection of the skeleton frame itself has now been lost because of the other operations necessary for enclosure.
When a concrete frame is used, there is considerably more time required in the erection. Figure 1 graphically illustrates why this is so. A maze of formwork, shoring and braces must first be built and remains in place while the concrete is poured and sets. There is usually a one to two weeks lag before the forms can be stripped, the shoring removed and the other trades are able to move in for their work.
Figure 2 shows the complicated form work necessary for a reinforced concrete wall. Reinforced brick masonry (RBM) can often do the same job more economically and provides a wall with a permanent and beautiful face on both sides.
Scaffold is expensive in the skeleton frame system. In addition to the swing stage usually required for exterior work, the mason contractor must also supply scaffold for the backup as well as interior walls, since these portions require that units be laid up from the inside of the building. This also requires a certain amount of double handling of materials.
In wall bearing multi-story work, the mason contractor sets the pace. He builds the structural elements for each story or portion of a story in one operation. Then the floor system is placed and, usually, the rough slab poured. This system allows a more rapid follow-up by other trades, which can result in earlier occupancy of the building.
The important interrelation of the structural wall system and the floor system requires careful scheduling by both the mason contractor and the general contractor. However, through this close coordination of efforts, and because of the simplicity of the construction sequences, definite construction economies are possible.