How to Boost Home Performance and Durability with Foundation Vapor Protection
Aligned with this objective are self-educated homeowners and potential buyers seeking high-performance homes. Consequently, builders, along with raters and architects who assist them, are actively seeking product solutions that:
According to the EEBA,
- Add value to their customers’ investments
- Demonstrate a core commitment to being a “responsible” builder
- Differentiate themselves in a competitive marketplace
Our hope at Stego (and the purpose of this article) is to help provide useful support and education so that EEBA builders can better understand vapor transmission at the first side of the home – the foundation – and the role below-slab vapor barriers play in achieving high-performance goals in new homes.
No, we are not talking about commodity 6 or 10-mil poly sheeting. Minimum residential code (2021 IRC Section R506.2.3) no longer allows generic poly sheeting beneath concrete floor slabs as a vapor retarder. Evaluating and selecting vapor barriers (or “retarders”), beneath a concrete slab, necessitates different considerations and product performance benchmarks compared to how we think of controlling vapor across the building enclosure (like in the walls).
Quick Note: although this article focuses on vapor protection beneath concrete slabs (on-grade or in a basement), much of the science, material performance considerations, and goals apply directly to crawl space construction as well. In many ways, effectively controlling vapor from the ground in a crawl space (any crawl space, but especially unvented, conditioned crawl spaces) is even more critical to the performance, durability, and indoor air quality of the home. You can learn much more about crawl space vapor protection at www.stegoindustries.com/blog
