Initially, water vapor diffusion was seen as the likely culprit for condensation problems; designers and consultants spent hours running and analyzing wall assemblies using the dewpoint method. With such analyses came the concept the wall system should be tuned for maximum condensation resistance by altering or selecting the appropriate permeability of the wall components. However, to create a truly robust wall system with the greatest condensation resistance and drying potential, designers need to look at altering the temperature profile of the wall assembly by moving insulation as far as possible to the exterior of the wall.
The December 2013 issue of The Construction Specifier included the article, “Out of Sight, Not Out of Mind,” by Ram Mayilvahanan. The feature focused on expanded polystyrene (EPS) and included reference to a particular industry study. In response to the piece, we recently received the following e-mail from John Ferraro, executive director of the Extruded Polystyrene Foam Association (XPSA):
This article included conclusions on the long-term thermal performance of XPS in below-grade applications contrary …
Plaza construction typically incorporates various products from different manufacturers intended to provide the thermal resistance, water management, structural capacity, and wearing surface needed to meet a particular project’s requirements. This article discusses the importance of evaluating the strength and stiffness characteristics of a plaza system, particularly when heavy loading is anticipated. Designs that do not properly account for overall system strength and stiffness are vulnerable to damage, potentially resulting in cracking and displacement of the hardscape materials, reduction of drainage capacity, and reduced service life of the plaza.
For decades, the U.S. design and construction industry has turned to sprayed polyurethane foam to insulate and air seal buildings. When used as a roofing material, its monolithic nature allows for a seamless, self-flashing application that can keep out water. SPF can also improve energy efficiency, helping building owners and general contractors comply with energy codes and meet performance requirements for green building programs and certifications.