If you are designing a gymnasium, big-box retail, or one of several other building types, you can still utilize integral-insulated exposed single-wythe concrete masonry (CMU) walls for code compliance. This cost-effective wall system remains a prescriptive path design option in the latest Washington and Oregon energy codes.
The links below give more information about these energy codes.
NWCMA Tek Note
Article by Tom Young
The following Guide Specifications were written as the framework for a specifications section. The Guide Specifications appear in the CSI three-part format on the left hand pages with explanatory information on the adjacent right hand pages titled NOTES TO SPECIFIER.
Each Guide Specification addresses a particular type or use of masonry construction. They should serve as a guide only and they must be revised and customized for each particular project.
When using any specification the Specifier must consider applicable building codes, local practices and the particular features of the project. The Specifier may find it useful to combine some of these specifications into one specification for smaller projects.
This technical bulletin discusses the application of concrete masonry units in anchored veneer construction. Concrete masonry can provide a durable, aesthetically-pleasing exterior facade over various backing surfaces for a variety of building types. This bulletin focuses on the control of non-structural cracking of concrete masonry veneer to maintain the appearance and water resistance desired.
The following Guide Specification was written as the framework for a specification section. It appears in the CSI format on the left side with explanatory information in the Notes to Specifier on the right. When using this Guide Specification, the specifier must consider applicable building codes and particular requirements of each project. A complete reinforced concrete masonry construction Guide Specification is available from the NWCMA office.
Ground-face concrete masonry units (CMU) provide architects and designers with an attractive architectural block texture. Ground-face CMU are produced by grinding the top 1/16 inch off the face of standard block with an abrasive cutting head to reveal the natural colors of the aggregates. This process provides a smooth textured unit available in a wide range of integral colors.
Concrete masonry is a noncombustible construction material possessing excellent fire-resistive properties. The resistance of concrete masonry to fire is well established by extensive testing to be a function of the type of aggregate used in the manufacture of the masonry units and their equivalent thickness.
Integrally colored concrete masonry is commonly used as an architectural material in the Pacific Northwest. By combining different block sizes and shapes, colors or surface treatments, architects have designed many striking buildings. The interest in architectural block led to the development of industry recommendations for rain resistance. This updated technical note addresses the design and specification of a concrete masonry wall system for the western portion of the states of Washington and Oregon where rain resistance is a major concern. Some of these recommendations may not be applicable to the more arid regions of the Northwest.
This publication focuses on weather-exposed, single-wythe concrete block walls. These walls are assumed to be coated with a clear water repellent rather than an opaque coating for aesthetic reasons. They are designed as barrier walls and reinforced and grouted to withstand the forces of wind and earthquake, making the use of internal wall flashing impractical.
Architectural concrete masonry units (CMU) are available in a wide variety of sizes, shapes and surface treatments. Integral color can be added to concrete masonry units further increasing the design potential. Integrally colored concrete masonry block units provide a long lasting, low maintenance, attractive finish to masonry structures.
A proper understanding of the benefits and limitations of integrally colored CMU can assist in meeting satisfactory expectations for the finished masonry wall assembly. This will help to avoid possible disappointment in the wall’s appearance.
The sustainable building movement has gained momentum over the past several years. Rating systems such as LEED and Green Globes have helped to drive this movement. Masonry materials can contribute significantly toward rating system compliance. (See Figure 1.)
Now we must consider the implications of new green building codes that are being developed. ASHRAE/USGBC Standard 189.1 has been published as has the International Green Construction Code (IGCC). At times there have been unintentional consequences of using the rating systems. Most notably, in their misapplication in the form of requirements rather than providing guidance. Codes and standards on the other hand are legal documents with mandatory provisions that can be directly adopted by a city or state government.
Cracking in buildings normally results from restrained movement. This movement may originate within a building material due to temperature change or shrinkage or may result from movement of adjacent building elements. In most cases, movement is inevitable and must be accounted for during design if cracking is to be controlled.
Control joints placed in concrete masonry walls are one method of crack control. Control joints are vertical separations built into a concrete masonry wall to reduce restraint and permit longitudinal movement. They are located where cracking is likely to occur due to excessive tensile stress.
For more information, see our Tek Note below, updated April 2023.