Masonry Magazine May 1970 Page. 28
Calgary, Alberta. (Architect-Abugor & Sunderland: general contractor S. Hashman Ltd.; mason contractor- Pockar Brothers Ltd.)
A new thin-bed mortar system, the Monowall Construction System, also is gaining acceptance by contractors and designers. This method, which has the advantage of using standard production block, has been developed by Intercon Research Inc. of Indianapolis specifically for use with Threadline adhesive mortar.
In Monowall construction, the blocks are stacked vertically (i.e., turned on end 90°) from the normal horizontal position. This eliminates the grinding operation, because the block ends have sufficient dimensional accuracy as molded for thin-bed mortar joints. An initial leveling course with conventional mortar is usually required, after which the block is stacked vertically in a running bond pattern on subsequent courses.
Monowall construction is comparable in strength to walls built by conventional methods. The compressive strength of the block in the vertical direction is slightly less, but not enough to require altering the wall thickness. The excellent tensile strength of the Threadline mortar joint meanwhile increases the bending strength of the wall to ten times that of conventional construction.
Two low-income housing projects in the Detroit area are using Monowall for both exterior and interior load- bearing and nonload-bearing walls. These projects, the recently completed 24-unit Nagel Plaza apartments and the 480-unit Martin Luther King Homes now under construction (architect/general contractor-Campbell Group; mason contractor-Monte Costella & Company), are being closely observed by local and national authorities for new techniques that can help to lower the cost of new housing.
Surprisingly, one of the many ways Monowall is reducing costs on projects is for interior partitions, both load-bearing and nonload-bearing. Partitions of four-inch Monowall are being erected at in-place costs equal to or less than partitions erected with lower performance materials. And these interior walls provide the same excellent fire resistance and acoustical characteristics as a conventional masonry wall. They are superior to dry wall systems at approximately the same cost.
Mechanicals are accommodated by installing vertical runs first and building the wall around them by using bond beam blocks or U-blocks. Lateral runs can be installed after the wall is completed, because the block cores are now horizontal.
The new 14-story Education Building in Calgary, Alberta (general/mason contractor-Burns & Dutton), was recently constructed with Monowall partitions throughout. This choice was made only after a thorough study of the relative cost and performance characteristics of metal stud partitions.
The vertical joints of Monowall are open, so the surfaces of these walls are finished. Nonload-bearing interior walls can be finished with a variety of materials, including wood paneling, dry wall, insulation board and plaster. Load-bearing interior walls should be finished with plaster. Only a 3/16"-thick coat is necessary to provide a durable, attractive finish. Such thin plaster is possible because there are no wide mortar joints to cause differential suction between the block and joint.
Exterior load-bearing walls should be finished with stucco modified with Styrocrete brand mortar additive. A 14"- thick coat of this modified stucco is adequate for a weatherproof, crack-free finish. An excellent finish for the inside of exterior walls consists of a layer of Styrofoam brand plastic foam insulation followed by a coating of plaster. This was the system used on the Nagel Plaza and Martin Luther King apartments in Detroit.
The advantages of adhesive mortar are not limited to the interior and exterior walls of a building. Decorative elements, such as solar screens, are more attractive and easier to erect with thin-bed mortar. The sides of the block, which are the joint surfaces, are accurately molded and suitable for thin-bed mortar joints. The early bond of a mortar such as Threadline expedites construction and the absence of thick mortar lines enhances the finished appearance of the unit-proving block is beautiful.
Code approvals of construction systems using Threadline adhesive mortar are progressing at a rapid pace. The Ground Block System for load-bearing walls has been approved by the FHA for more than six years, and it has been granted similar approval by all the other material codes. Nonload-bearing walls of Monowall construction also have the approval of FHA and most other building codes.
Load-bearing Monowall has been granted approval by a growing number of codes such as the Southern Building Code Congress and by many local codes. In a number of areas where approval is still pending, releases for specific projects have been granted. Work is continuing at both the national and local levels to obtain complete code approvals for this lower-cost, efficient construction method.
One section of Martin Luther King Apartments under construction in Detroit. The 480 unit complex is expected to be completed in 1970.
Prefabricated panels of block, held together with Threadline ad. hesive mortar by The Dow Chemical Company, were produced at a plant and trucked to the job site at the Village West Project, Louisville, Kentucky.
masonry May, 1970