Building Walls Subject to Water Intrusion and Accumulation: Lessons from the Past and Recommendations for the Future contains peer-reviewed papers that were presented at a symposium held April 14-15, 2013 in Indianapolis, IN. The symposium was sponsored by ASTM International Committee E06 on Performance of Buildings and Subcommittee E06.55 on Performance of Building Enclosures. The Symposium Co-Chairpersons and STP Co-Editors are Jeffrey Erdly, Masonry Preservation Services, Bloomsburg, PA and Paul Johnson, Smithgroup JJR, Inc., Detroit, MI. The papers that compose this STP will assist design and construct professionals better performing and longer lasting buildings. More information is available at: http://www.astm.org/DIGITAL_LIBRARY/STP/SOURCE_PAGES/STP1549.htm