Stego IQ returns with the latest episode dispelling the myth about vapor barriers and slab curl. Dan Marks, Stego's Technical Director, returns to the screen to explain the short term slab curl effects with a vapor barrier as well as the long term effects of slab curl if you do not install a below slab vapor barrier.
A Narrative History of the Biggest Myth around Under-Slab Vapor Barriers
5 Tips and Tricks for Sealing the Terminating Edges of the Vapor Barrier
Photo courtesy of Chavez Concrete Contractors, Inc.
Despite its cost being measured in mere cents per square foot, project designers, contractors and building owners often disregard a high-performance under-slab vapor barrier. Yet, failing to use this vital material may be the best illustration in the construction industry of “a penny wise and a pound foolish” – unnecessarily risking costly consequences and potentially years of legal squabbling over liability.
Here are 10 critical reasons why you should always use a high-performance vapor barrier, no matter the project:
“Vapor retarder” is the term used to describe materials of varying types and classifications which impede the infiltration of water vapor into a structure. Often the term “vapor barrier” will be used interchangeably with the term “vapor retarder,” with no repercussions. But for under-slab applications, it is important to understand the distinctions between the two terms to avoid negative impacts on your project.
ASTM International, formerly known as the American Society for Testing and Materials (ASTM), is a globally recognized leader in the development and delivery of international voluntary consensus standards. Today, some 12,000 ASTM standards are used around the world to improve product quality, enhance safety, facilitate market access and trade, and build consumer confidence.
ASTM (American Society for Testing and Materials) E1745 is the Standard Specification for Plastic Water Vapor Retarders Used in Contact with Soil or Granular Fill under Concrete Slabs. This standard requires products undergo conditioning testing designed to simulate in-service (under-slab and installation) conditions, and it classifies vapor retarders based on their tensile strength, puncture resistance, and water vapor permeance ratings.