Concrete for Residential ConstructionConcrete for Residential Construction
The new version of the ACI 332 Code provides prescriptive code requirements for foundation walls and design requirements for structural concrete.
November 20, 2020
Recent predictions indicate that commercial construction may suffer during 2021 but residential construction is booming in many parts of the nation. Make sure you know the code requirements for residential concrete design and construction: ACI 332-20, Code Requirements for Residential Concrete, and, of course, the International Residential Code.
Design and construction of residential buildings in the U.S. is governed by the International Residential Code (IRC). The IRC is incorporated by reference into the local codes for all counties and cities. The IRC includes provisions that apply to the design and construction of residential concrete but includes ACI 332 as an acceptable alternative. ACI 332 includes enhanced detailing and prescriptive designs as well as design of concrete construction systems that the more general IRC doesn't accommodate. When the simple prescriptive design tables in ACI 332 are used, the IRC exempts the design from needing an engineer’s stamp. This allows a concrete foundation contractor to design the walls in-house.
The 2020 version of ACI 332 has just been released by the American Concrete Institute. As with previous versions It covers the design and construction of cast-in-place concrete for one- and two-family dwellings and multiple single-family dwellings (townhouses), and their accessory structures. Among the subjects covered are the design and construction requirements for plain and reinforced concrete footings; foundation walls; slabs-on-ground; and requirements for concrete, reinforcement, forms, and other related materials. Background details or suggestions for carrying out the requirements or intent of the 332 code are provided in the commentary. The commentary discusses some of the considerations of the committee in developing the code with emphasis on the explanation of provisions that may be unfamiliar to code users or where significant departure exists from other concrete codes.
The 2020 version of ACI 332 has both major and minor revisions from the 2014 version. The minor revisions include:
The exposure categories and classes have been modified
The discussion concerning vapor retarders has been expanded
Commentary on finishing has been expanded
Commentary on hot weather concreting has been expanded
Contraction joint language and requirements have been modified
And the table o fiber reinforcement has been revised
There are also two major revisions in the 2020 version of the 332 Code:
Entire new chapters have been added that provide a comprehensive method for design of structural concrete to complement and expand on the prescriptive design, including for footings, foundations, above-grade walls, and lintels
There is detailed information on connections to lateral support systems
A technical note that details and explains the ACI 332 Code is available from the Concrete Foundations Association (TN-001). To purchase the new ACI 332-20, click here. It is $99.00 for nonmembers of ACI or $59.00 for members.