Lap Splice & Development Length Calculator
This calculator is based on the provisions of TMS 402/602-16 and TMS 402/602-22, Building Code Requirements and Specification for Masonry Structures. As there is no functional difference between the requirements of these two editions of the masonry design standard pertaining to the determination of minimum lap and development lengths, either edition is applicable.
Thermal Catalog of Concrete Masonry Assemblies, 2nd Edition
Energy codes continue to evolve and requirements for building envelopes continue to tighten. Fortunately, concrete masonry construction provides a wide variety of options to meet the energy needs of nearly every project. This catalog of assemblies provides code-supported R-values and U-factors for thousands of concrete masonry assemblies. Single-wythe, multi-wythe, various insulation locations, and additional finish systems are all included. Assemblies from R-3 to R-30 and more can be found in this guide.
Outdoor-Indoor Transmission Class of Concrete Masonry Walls
Providing a quality indoor acoustic environment is becoming a higher priority in many cases; particularly in urban environments where noise from traffic and other outside sources can be a significant distraction, especially in schools, homes and the workplace. Concrete masonry walls provide excellent noise control due to their ability to effectively block airborne sound transmission over a wide range of frequencies.
Noise Control with Concrete Masonry
Sound control is an important design consideration in most buildings. Sound control involves two important properties: sound transmission and sound absorption, as depicted in Figure 1. The International Building Code (IBC, refs. 1, 2) contains minimum requirements for sound transmission in certain situations (see Sound Transmission Class Ratings of Concrete Masonry Walls, TEK 13-01D, ref. 3). However, the IBC does not contain minimum requirements for sound absorption, although proper control of sound reflected back into the room is a very important design function in many buildings as well, such as concert halls, gymnasiums, places of assembly, rooms containing loud equipment.
Sound Transmission Class Ratings for Concrete Masonry Walls
Unwanted noise can be a major distraction, whether at school, work or home. Concrete masonry walls are often used for their ability to isolate and dissipate noise. Concrete masonry offers excellent noise control in two ways. First, it effectively blocks airborne sound transmission over a wide range of frequencies. Second, concrete masonry effectively absorbs noise, thereby diminishing noise intensity. Because of these abilities, concrete masonry has been used successfully in applications ranging from party walls to hotel separation walls, and even highway sound barriers.
Concrete Masonry Unit Shapes, Sizes, Properties, and Specifications
The most widely used standards for specifying concrete masonry units in the United States are published by ASTM International. These ASTM standards contain minimum material and property requirements that assure quality performance. These requirements include items such permitted constituent materials, minimum compressive strength, maximum linear drying shrinkage, maximum absorption, permissible variations in dimensions, and finish and appearance criteria.The letter and first number of an ASTM designation is the fixed designation for that standard. For example, ASTM C90 (REF. 1) is the fixed designation for loadbearing concrete masonry units. The number immediately following indicates the year of last revision (i.e., ASTM C90-16 would be the version of C90 published in 2016). Because significant changes can be introduced into subsequent editions of standards, the edition referenced by the building code or by a project specification is an important consideration when determining specific product requirements. For the discussion presented here, the ASTM requirements reviewed have remained relatively static unless otherwise noted.
Design for Dry Single-Wythe Concrete Masonry Walls
Single-wythe concrete masonry walls are cost competitive because they provide structural form as well as an attractive and durable architectural facade. However, because they do not have a continuous drainage cavity (as do cavity and veneered walls), they require special attention to moisture penetration.
Joint Sealants for Concrete Masonry Walls
Successfully sealing joints, such as control joints and around door jambs and window frames, in concrete masonry walls depends on the overall design and construction of the entire building envelope. Movement joints (also called control joints) are needed in some concrete masonry walls to accommodate drying shrinkage, thermal movements, and movements between different building components. Movement joints, joints around fenestration, doors and penetrations, and isolation joints (joints at dissimilar material interfaces) rely on joint sealants to help preserve the overall weather-tightness of the building envelope. In addition, properly sealed joints may be required to meet a specified fire resistance rating or sound transmission class.
Flashing Details for Concrete Masonry Walls
At critical locations throughout a building, moisture that manages to penetrate a wall is collected and diverted to the outside by means of flashing. The type of flashing and its installation may vary depending upon exposure conditions, opening types, locations and wall types. This TEK includes typical flashing details that have proven effective over a wide geographical range. The reader is also encouraged to review the companion TEK 19-04A Flashing Strategies for Concrete Masonry Walls (ref. 1) which addresses the effect of moisture on masonry, design considerations, flashing materials, construction practices, and maintenance of flashing.
Flashing Strategies for Concrete Masonry Walls
The primary role of flashing is to intercept the flow of moisture through masonry and direct it to the exterior of the structure. Due to the abundant sources of moisture and the potentially detrimental effects it can have, the choice of flashing material, and the design and construction of flashing details, can often be as key to the performance of a masonry structure as that of the structural system.