Masonry Magazine February 1995 Page. 53
The Upscale Look
Continued from Page 16
treatment plant. Coffey says, "It provides an impregnable, durable surface that can be easily cleaned."
Kennedy Associates, along with Leonard Masonry Co., is currently working on an unusual masonry design project. For the St. Louis Convention Center/Stadium Addition, a ribbed unit was used in all concourse areas and alternated with ground face block. Coffey says. "The texture allowed us to accent the appearance of the block and give it a little more life than a smooth surface would."
"The Rockwood Valley Middle School project, with St. Genevieve Building Stone as mason contractors, was a combination of brick and CMU that was chosen to reflect the surrounding rocky environment," says Coffey. "Each earth tone shade of masonry on the exterior is a metaphor to emphasize the stratification of sedimentation rock in the area."
Mitchell-Hugeback Architects selected concrete masonry for two recent school projects. The 35,000 square foot Whitfield School, constructed by Swanson Mason Contractors, combines a four foot base of split face CMU and brick masonry above.
Properties of Concrete
Masonry
THE UNIQUE PROPERTIES of concrete masonry make it unlike any other wall system. CMU provides strength as a backup, and it can be used as an attractive exterior or interior wall as well. In many cases, it functions as all three.
The rigidity of the concrete masonry backup system allows it to carry the majority of the lateral load of the structure. Other systems will deflect a larger portion of the lateral load to the veneer. A flexible system like steel stud will cause the veneer to share most of the load and increase the opportunity of veneer cracking.
The mass and density of concrete masonry units render it both a fire resistant and thermal efficient building material. Concrete masonry remains structurally sound at temperatures up to 2,000 degrees. This, in turn, offers owners the benefit of lower insurance premiums over other systems, often as much as three times lower. The thermal dynamic properties of CMU help minimize heat loss in cold weather and heat gain in the summer. Its intrinsic storage capabilities help reduce heating and cooling loads. Long term energy savings can be substantial.
Concrete masonry's mass also gives it inherent soundproof capabilities. Institutions like schools, libraries, hospitals and offices find the sound reduction an added benefit.
The corrosion and impact resistant surface of CMU make it a low maintenance material. Moisture, the bane of all building materials, can also be problematic for concrete because of its porous nature. Jamie Cannon, President of Jamie Cannon Associates, and president of AIA St. Louis, says, "The key is not just specifying a moisture barrier, but in checking each phase of construction to make sure the CMU is installed correctly."
Mark Wilhelms, director of sales and marketing for F.F. Kirchner Inc., says, "There needs to be a team approach to designing moisture resistant walls." This approach includes:
The Masonry Manufacturer has to produce a good quality unit that is tight and dense. He can also put in additives to make it more moisture repellent.
The designer or architect has to design the wall system properly. This especially means incorporating flashing, weeping, coping and other details.
The quality of the workmanship in the field means the bricklayer has to use full mortar bedding and well tooled joints.
The contractor has to make sure it is built the way the architect designs it, including putting the flashing and the weepholes properly.
It is also important that the masonry units are protected and covered during all phases of construction.
During extremes of weather, Wilhelms says that extra precaution should be taken. He says, "Keeping the units dry is especially important during the winter and spring months." This includes protecting units being laid and materials stored on site.
Don Kirchner, president of F.F. Kirchner, Inc., says, "Concrete block is probably the finest building material available when you consider its properties. It provides structure for the building's roof and lateral loads, a finished wall system, a decorative appearance, low maintenance and permanence."
DUR-O-WAL®
FLASHING
SYSTEMS
Whether
you need
economical
composite flashing
or premium stainless steel,
DUR-O-WAL's got you covered.
DUR-O-WAL DCF
A unique composite flashing that provides all the benefits of copper without the negatives. Unaffected by extreme temperatures or deterioration due to acid or alkali reactions, it can be used virtually anywhere through-wall flashing is needed. Flexible, easy-to-use and less expense than most copper composites, DCF offers two economical choices:
DCF-1500S-A base material of metal foil encapsulated in a polyester film and bonded to a fiberglass scrim.
DCF-1501B-A base material of vinyl ethylene film bonded to a fiberglass reinforcement.
DUR-O-WAL STAINLESS STEEL
DUR-O-WAL stainless type 302/304 flashing for maximum corrosion resistance and longevity can be used for the most demanding through-wall flashing applications. Available in 16 ga., 22 ga. and 26 ga. sheets. Drip-edge flashing (D/A-1526) and other preformed shapes available on request.
For more information contact your factory authorized distributor or call toll-free:
1-800-323-0090
DUR-O-WAL, INC.
3115 N. Wilke Road, Suite A
Arlington Heights, IL 60004
(708)577-6400 Fax (708) 577-6418
MASONRY-JANUARY/FEBRUARY, 1995 53