Be sure to understand the messenger before you trust the message; a simple statement with meaning. We, as consumers, receive messages at all times of day; the world is FULL of information…internet searches, news stories, e-mail blasts. We have become mechanical in our presenting of findings, ‘have you seen this’, ‘have you read that..’, and are quick to trust worthy sources without any further understanding.
As you’ve come to imagine, this week’s blog is fueled by a similar matter and today we hope to provide further understanding. In a recent article written by the Construction Specifier titled, “Selecting Polystyrene Foam Where Moisture Exposure Occurs,” XPS and EPS are compared in building applications where moisture is expected.
In an effort to further promote our partnership with the EPS Alliance Industry, we would like to highlight a few of their comments regarding the inaccuracies found in the article. According to a recent release by Tyler Merchant, Public Relations Manager of the EPS Industry Alliance, “Several claims are made regarding XPS’s resistance to moisture absorption, and that “industry experience has shown XPS to provide superior performance in the exterior foundation insulation application”. This is hardly an accepted fact, as shown by EPS insulation’s significant market share. Furthermore, an important consideration when comparing XPS and EPS is that when subjected to moisture absorption and drying in accordance with ASTM C1512, EPS is better suited to release moisture than XPS.”
Also stating that, “the article makes the assertion that “long‐term exposure to moisture makes it imperative the insulation of vegetative roof systems retains R‐value”, and therefore XPS is the material of choice for vegetative roofs. If R‐value retention is such an important factor for vegetative roofs, it should be mentioned that XPS – as a closed‐cell foam insulation with a blowing agent or gas other than air – is known to lose its R‐value over time “…due primarily to diffusion. This results in a general reduction of the thermal resistance of the foam due to an increase in the thermal conductivity of the resultant gas mixture”. Conversely, “rigid gas‐filled closed‐cell foam insulation products produced using blowing agent gases that diffuse very rapidly out of the full‐thickness foam product, such as expanded polystyrene…”, retains a consistent R‐value. A fair and balanced comparison would make mention of these facts.”
Here at Plymouth Foam, we are proud supporters of educational information that enhances the knowledge of EPS foam and the benefits it brings to our communities. Thank you to the EPS Alliance Industry for providing our industry with a factual overview of the Construction Specificer’s article; we look forward to seeing it published as a letter-to-the-editor correction in the near future.