Dow Finds Moisture in Commonly Built Homes

Breathable walls are not necessarily better walls.

Midland, MI - March 21, 2016 -  Dow Building Solutions (DBS), a business unit of The Dow Chemical Company (NYSE:DOW), challenged the norm for residential building science through its latest findings of moisture in home durability. Through its Building Better Homes Challenge, formally referred to as the Twelve Energy Efficient Test Homes (TEETH), Dow discovered moisture content exceeding 20 percent on the surface of the oriented strand board (OSB) in most homes in the study built with 2x6 R19 fiberglass insulation, OSB and housewrap. The study has been an ongoing project in collaboration with Cobblestone Homes and DBS to investigate the performance of commonly built wall assemblies. Beginning in 2012, and announced by Dow in 2013, the study has evolved to provide insight into the effects energy codes play in eliminating, and alternatively, potentially creating moisture in the wall cavity.

Dow collected four consecutive years’ worth of data showing homes built with OSB and housewrap, regardless of the building code standards, retain high levels of moisture content throughout the winter season in a cold climate zone. Meanwhile, homes built with continuous insulation using STYROFOAM™ Brand Extruded Polystyrene (XPS) Insulation did not. Contrary to the industry’s popular building beliefs, permeable wall layers – “breathable walls” – are not drying fast enough to the outside to overcome the interior moisture condensing on the OSB.

“What we learned from this study was that even with the best building practices and highly reliable products on the market, only four winters can lead to signs of moisture exposure in new homes built with OSB and housewrap,” said Brain Lieburn, DBS research scientist. “A breathable wall isn’t always a better wall. When it comes to moisture, continuous insulation using foam sheathing provided higher protection from condensation for the homes in our study.”

To validate the alarming amount of moisture content found in the wall cavities, samples of OSB from several homes were sent to Dow’s microbial lab for further examination. While very little evidence of active fungal decay or molding were found, the OSB sampled from the homes built with OSB and housewrap did show signs of moisture exposure that may to lead to future long-term problems which may include house mold, airborne allergens and rotting walls.

“75 years ago Dow discovered a technology that would revolutionize the building market. Today, our building science demonstrates continuous insulation using XPS helps provide the most reliable home insulation solution for the market,” said Matthew Marchel, DBS business director.


About Dow Building Solutions

Dow Building Solutions serves the residential and commercial building and construction markets with an industry-leading portfolio of products and integrated systems designed to insulate and seal the whole building envelope. Beginning more than 75 years ago with our flagship STYROFOAM™ Brand Extruded Polystyrene (XPS) Foam Insulation, Dow has continued to offer innovative insulation, weatherization and air sealing solutions that work behind the scenes – above grade, below grade – to help builders and contractors deliver more comfortable, durable and affordable buildings. Follow Dow Building Solutions on FacebookTwitterYouTube and LinkedIn or subscribe to our News Release RSS Feed.

About Dow

Dow (NYSE: DOW) combines the power of science and technology to passionately innovate what is essential to human progress. The Company is driving innovations that extract value from material, polymer, chemical and biological science to help address many of the world's most challenging problems such as the need for clean water, clean energy generation and conservation, and increasing agricultural productivity. Dow's integrated, market-driven, industry-leading portfolio of specialty chemical, advanced materials, agrosciences and plastics businesses delivers a broad range of technology-based products and solutions to customers in approximately 180 countries and in high-growth sectors such as packaging, electronics, water, coatings and agriculture. In 2015, Dow had annual sales of nearly $49 billion and employed approximately 49,500 people worldwide. The Company's more than 6,000 product families are manufactured at 179 sites in 35 countries across the globe. References to "Dow" or the "Company" mean The Dow Chemical Company and its consolidated subsidiaries unless otherwise expressly noted. More information about Dow can be found at

Stacy Coughlin +1 9896363731