I was doing some online research yesterday and ran across several interesting articles/URLs discussing the unintended consequences of tightening buildings to save energy. One thing they all had in common was that creating a tight building envelope more often than not leads to SBS. Building envelopes that can’t drain or breathe lead to entrapped moisture issues. It doesn’t take a great deal of effort to find information related to this issue, and I encourage you to do so. It is this very idea that has lead to the tremendous interest in the rainscreen or curtain wall method of building.
MTI has done a great deal of study on this issue as have many of the recognized building envelope moisture management authorities including Lstiburek, Burnett, Straube, Karagiozis and Williams. ASHRAE commissioned a study of air movement in walls recently, and the report is well worth reading. MTI has a report on Sure Cavity Moisture Testing that specifically addresses how little entrapped moisture it takes to create serious SBS problems. I also would encourage you to take a look at our short Course 1 in Drainage Plane University found on our Education page.
It’s important to build for energy efficiency! However, we need to plan and build to counter the entrapped moisture issues that come with it. Those our my thoughts, I welcome yours!