Stuccometrics: Stucco Jointing – The Why, When, Where, and How
Presented by Jeff Bowlsby, CCS, CCCA of SGH
Exterior stucco cladding can be categorized into one of two configuration types—either directly-applied to cementitious and masonry substrates (barrier walls), or applied over lathing that is mechanically fastened over a water-resistive barrier to steel- or wood-framed substrates (drainage walls). Both configurations often employ a range of stucco cladding jointing types serving different functional and aesthetic purposes. The objective facts of Why and When stucco jointing is needed or not needed, Where joints are needed, and How joints are designed and constructed are explored, including significant new information that promotes knowledge and understanding to improve the performance and quality of stucco claddings, which are often misunderstood.
This article is based on historical development, design, and installation requirements; building code and reference standard requirements; and the results of recent stucco jointing performance testing. Provided illustrations will depict stucco jointing construction detailing, lathing accessories, splicing, intersection and termination requirements, and plaster application methods used to configure stucco jointing. This presentation factually and objectively explains essential requirements and considerations for effective stucco jointing to assist stucco cladding designers and craftsmen. Jointing facilitates drainage, accommodating building substrate movement and cement plaster shrinkage movement, thus reducing cracking, while it terminates cement plaster panel areas and has decorative purposes.