Jeff Bowlsby CCS, CCCA

Exterior Wall and Stucco Consultant

Licensed California Architect


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Introduction and the Effective Use of



Webpage Quicklinks



Stucco Metrics Definition

Effective Use of


S    T    U    C    C    O        E    X    C    E    L    L    E    N    C    E




“…Firmness, Commodity and Delight…”



These succinct, definitive Vitruvian architectural characteristics describe the essence of what stucco is and wants to be.  While is fundamentally a stucco information resource, it has the capacity to become much more.  This place is envisioned as a venue for bridging the voids between stucco theory and stucco reality, and between stucco technology and stucco creativity. explores and promotes the effective utilization of stucco materials and technology, with technical rigor, in pursuit of architectural vitality and excellence.


Stucco is an architectural skin, the outer clothing, the shielding armor of a building, and its aesthetic, functional and technical qualities are an integral part of the critical first impression of a building. You know what they say about making first impressions.  Stucco is a highly visible and tactile architectural system.  Like the finish on a new car, stucco can be crafted to exude a distinctive image as a design statement or be purely pragmatic.  Stucco’s aesthetic characteristics are significant to architects, building owners and stucco craftsman, because they are a non-verbal statement on the quality of the architectural experience and of their professional abilities and efforts.  It is the challenge to us collectively to determine the role stucco plays in the quality of the architectural experience.





Stucco:  stuc·co  [stuhk-oh]  noun, plural –coes, -cos, verb, -coed, -co·ing.  An exterior finish for masonry or frame walls, usually composed of cement, sand, and hydrated lime mixed with water and laid on wet.      (


Metrics:  [me-triks]  noun,   a combining form with the meaning “the science of measuring” that specified by the initial element: biometrics    (





Effective use of


1.               For convenience and easy access, use the Quicklinks index at the top of each webpage and other navigational links where they occur


2.               For the basic concepts and terminology used on, carefully review the Essential Principles webpage


3.               For stucco movement joints information, carefully review the webpages for Material Properties and Stucco Cracks, then the PMJS, SMJS and BMJS webpages in that order


4.               For a range of artistic expressions possible with stucco, peruse the Architectural Aesthetics & Stucco Technology, Finish Texture, and Finish Texture Gallery webpages


5.               For specific Minimum Stucco Standards of Care and Best Practices review the Suggestions sections of specific technical webpages on an applicable topic, and in general, the Best Practices webpage


6.               For additional technical stucco topic information, review Stucco & Sealant, Stucco Buckets, Stucco Submittals & Shop Drawings and Proprietary Stucco webpages


7.               For specific manufacturers products, use the Product Manufacturer Links


8.               For further stucco research, use the Reference Archives webpage which includes the Stucco Essentials Suggested Reading List and Stucco Performance Testing documentation


9.               For stucco system consultation, see Stucco Presentations, Roundtable Discussions & Work Sessions and contact me

 is conceived to be a stucco information resource that serves everyone interested in stucco in the here and now, and well into the future – building owners, design and construction professionals, artisans, craftsmen, product manufacturers, and inspectors - to advance and proliferate the art, science, quality and performance of stucco exterior wall cladding assemblies.  The vision of is to have a part in forging a new paradigm for stucco, a viewpoint that takes this stucco exterior wall cladding material that has the characteristics of being wonderfully pleasing, durable, both technically and aesthetically into the 21st century.  For much too long stucco has been relegated to service where its technical and aesthetic capabilities have been uninspired and underutilized, particularly in recent decades where it has often been used in mundane ways with mundane aesthetics on rudimentary applications.  Cracking and water intrusion will be the death of stucco if we do not intervene and take the high road, but these challenges can be reasonably overcome with reasonable care, attention to detail and technology that we can and must implement NOW.  We have the wherewithal to make stucco and its use much more prolific, rewarding and invigorating than the position it holds today, or not, it is completely up to us.  Stucco can easily hold its own as a beautiful, functionally-effective and cost effective wall cladding material well into the future:


·                 The stucco aesthetic is timeless.  Stucco holds its own when applied with traditional, mission style and other common architectural style and aesthetics.


·                 Enhanced drainage


·                 Enhanced thermal efficiency


·                 Enhanced drainage and thermal efficiency with rainscreen wall cladding assemblies that efficiently meet the full range of the highest thermal efficiency and water resistivity performance expectations.


·                 No technical reason exists that would prevent stucco from being used as an alternate to expensive stone, metal panel and even more exotic cladding materials on everything from tall buildings, commercial, governmental and institutional buildings, to modest-scale buildings of any occupancy with the highest quality aesthetics, long term durability, fire resistance and all with a low life cycle cost.


·                 Hand-applied finish materials, textures and aesthetic qualities unlike any other exterior wall cladding material are possible and have only begun to be explored, which are fully-capable of satisfying any aesthetic expression requirements.


·                 Stucco has been the exterior wall cladding of choice for generations and it can and will meet and exceed ever-increasing challenges into the future.


·                 As a wet plaster, essentially a fluid-applied wall cladding, the most creative characteristic of stucco wall cladding is to express the fluid, dynamic, undulating forms of contemporary architecture, like no other wall cladding can.  Planar surfaces are one thing, three-dimensional, undulating curves are quite another.


·                 Experimentation may allow stucco cladding as screen walls, free-form and angular perforations, ornamental decorative patterns such as sgraffitto and more.


The primary purpose of is to be a sophisticated, technical resource of the most current, objective, relevant, performance-oriented and reliable technical information addressing selected, important, stucco-related topics not covered elsewhere, serving industry professionals in the design, construction, manufacturing and regulatory communities that concern themselves with stucco.  The information presented here will hopefully inspire you with the understanding of exterior stucco wall cladding assemblies from a fresh new perspective.  It is the only known current stucco resource presented from an architect’s viewpoint that discusses Minimum Stucco Industry Standards, Minimum Stucco Standards of Care, and Stucco Best Practices.  The essence of is to focus only on what is best for stucco without other distractions; admittedly it is only one opinion among many.  Its bias is decidedly pro-stucco, and not exclusive towards the designer, installer, product manufacturer or inspection communities.  If we work together to emphasize what is best for stucco over our own personal bias, then stucco will be successful and so will we.


Unlike most other stucco resources, the secondary purpose of is to encourage the exploration of stucco aesthetic expression including choices for the selection of stucco’s unlimited palette of textural possibilities. encourages the exploration and use of stucco as an aesthetic architectural feature as well as durable wall cladding material that can result in a rich architectural expression unlike any other wall cladding system.  You may find it interesting to know that portland cement was expressly invented to be an artificial stone for cladding buildings.  In addition to durability, stone is one of the most aesthetically pleasing building materials known to mankind and we can do much more with stucco than we presently do to capture the finer aesthetics of stone, interpreted and expressed, in the unique vocabulary of stucco.  Some will want to use stucco to emulate a very ‘stone-like’ aesthetic.  Others will want to express stucco with more integrity that capitalizes on the aesthetics of what stucco is on its own merits and not try to emulate something it is not.  While even the best quality stucco may not fully achieve all of the outstanding attributes and qualities of natural stone, stucco shares many of stones’ finer characteristics and improves on many of them.  The intrinsic physical qualities of stucco have few if any variations – durability, weather resistance, fire resistance, abuse resistance, and low initial life cycle and maintenance costs.  In certain respects stucco has superior characteristics to stone – such as its ease of conforming to a buildings’ articulated and curvilinear surfaces, its low initial installation cost, low long term maintenance cost, it is easy to suspend overhead, and is easily modified during building renovations.  In these and other respects we recognize that stucco is a premier wall cladding material – be encouraged to explore its attributes advantageously.


Cruising through the links on you will find detailed information and suggestions here and nowhere else.  This website approaches stucco with a new perspectives based on research, testing and practical necessity such as:


·                   Minimum Stucco Industry Standards

·                   Essential Stucco Principles

·                   Stucco as a System, Assemblies, Subassemblies and Components

·                   Stucco finish coat texture gallery

·                   Stucco movement joints

·                   Stucco crack typologies

·                   Stucco shop drawings:  Merging the art and craft of stucco

·                   Stucco and Sealant

·                   Stucco Best Practices 

·                   Website links to stucco products and manufacturers

·                   Website links to stucco organizations

·                   StuccoMetrics Reference Archive

·          Stucco Essentials Suggested Reading List

·                   And more…


Careful review of the information presented here to some, may reveal nothing new and is already your everyday practice.  To others, it may be at least partially if not completely new, and you are asked to have an open mind, ask questions, and thoughtfully consider how this new information may benefit stucco from the way you normally practice.  Challenging topics are addressed clearly and comprehensively and complex topics are simplified.  The information presented is the collective knowledge and perspectives from a wide range of industry resources throughout time.  Most of what you will find here is not really new it has just been hidden away, overlooked, suppressed, misplaced and sometimes misunderstood.  I hope you will recognize that the information here is based on the collective facts, research and experiences of many of the industry’s most authoritative and reliable sources, is not merely one person’s opinion, and that you will find it interesting and useful so that your use and experiences with stucco will benefit.  Identified references have been selected based on their authority as it relates to the stucco industry.  References such as the building code, Minimum Stucco Industry Standards, and major stucco product manufacturer sectors and their organizations, are the primary resources relied upon to be objective and authoritative.  A significant volume of other stucco industry resources are available that are not discussed.  These resources, while many may have morsels of wisdom, may be less objective, are not legally binding requirements, may contain conflicts with themselves or conflicts with more authoritative resources, or may simply be subjective and opinion-based without substantiation.  The emphasis is on understanding the larger context and interrelationships pertaining to stucco, and to become familiar with the best quality stucco information available.  Refrain from the natural tendency to isolate discrete items that may be influenced by personal bias or may be misconstrued or misinterpreted out of context - which may be isolated anomalies and not systemic conditions.  The approach here is that there are no conflicts regarding stucco, only conflicts in mutual understanding, from a lack of complete knowledge and assimilation of the larger context and interrelationships of its parts. 


Ostensibly, you will notice that some of the concepts and terminology used on are unconventional, and hopefully you will come to regard them as helpful and meaningful as they are intended.  In some instances terminology in common use does not clearly describe the function of certain stucco elements and new terms such as Building Movement Joint Subassembly (BMJS) and Shrinkage Movement Joint Subassembly (SMJS) are intended to not only identify, but to more clearly and intuitively describe the function of these subassemblies.  These and other acronyms used here are further intended to be useful as a descriptive identifier for architectural detailing and specifications to identify stucco assemblies, subassemblies and components.  These terms have been used privately for a while now and have been found to be useful in the way stucco assemblies, subassemblies and components are viewed, understood and interpreted.  Correctly designing, specifying, installing, inspecting and evaluating stucco systems can be a daunting and complicated process and this terminology system is hoped to make it easier for others, so they are shared here, in the hopes they may be helpful to you.




The Wigwam Motel, 1949

San Bernardino, CA


Everywhere one looks stucco is abundant, but all stucco is not the same.  Minimum quality exterior stucco wall cladding assemblies have different material and performance characteristics than stucco wall cladding assemblies of superior quality.  Stucco cladding systems and their components are not perfect solutions in every respect, but they can satisfy reasonable expectations. presents significant stucco information and research not readily available elsewhere with detailed references for those that want to research further.  It is a commentary encouraging the careful selection, specification and use of sound and proven stucco materials and practices.  It purposes to proactively inform industry professionals about stucco, to avoid design, construction, manufacturing and inspection errors that can cause disappointments, misunderstandings, marginal performance and failures with stucco, and to hopefully reduce stucco-related litigation.


X is not the first letter of any word that fits elegantly into a discussion about stucco, but it can represent an important check box on a checklist regarding stucco wall cladding design, material quality, construction and inspection.  With resourceful attention to good quality detailing, material specification, workmanship and quality control, stucco can easily be serviceable for the life of any building in any climate or geographic location.  Stucco is a beneficial exterior wall cladding from the sunbelt to the snowbelt, throughout many parts of the world.  Stucco’s worst enemy is our own lack of knowledge of its technological requirements and limitations, and our schedule and cost driven manufacturing and construction culture that precludes us from doing whatever is reasonably necessary to assure that stucco is successful, all of which are within our control.


Considerable advances in the design process and construction delivery methods already in the marketplace have led to preferences by an increasing number of building owners and architects for alternative stucco and exterior wall system procurement and delivery methods such as design/build, fast track design and construction methods that expedite the design and delivery process and facilitate quality control.  Entire exterior wall systems and their claddings can be delivered turnkey by specialist design professionals and exterior wall contractor design/build collaborations utilizing shop drawings for increased quality and optimized coordination, economics and installation.  One stop shopping from the architect’s design development package to the constructed wall system is advantageous to everyone involved.  That day is now for those who want the best exterior wall systems available.


Every reader has a different perspective and cannot be all things to all people in all circumstances and has limitations in scope.  Working together, stucco can and will advance and proliferate into the future.  Together, we can explore and develop ways and methods to make stucco the premier exterior wall cladding system of choice and to find effective means to address its challenges – especially cracking and water-related conditions.  Going forward, let us as stucco industry colleagues collectively strive to assure that stucco succeeds by achieving its highest potential, and in turn it will serve us without compromise or disappointment. 


Lots of other stucco resources exist, but none are quite like this place. is a work in progress and your patience is requested as it grows over time.  The selected topics presented here are but a few examples of many important topics that require consideration for the effective use of stucco, such as substrates and lathing, drainage subassemblies, continuous insulation, extruded aluminum terminations (EAT), low slope surfaces, the range of topics related to finishes and much more. has been developed, tested and used for several years privately already and a resource like this is rarely ever complete, so please contact me in the interim with any stucco questions you may have. can be conveniently accessed from your mobile device also so you can get information from any location or device with internet access – at the office, in the studio, on the jobsite or the manufacturing plant.  This resource is available at no cost or obligation to any party and is entirely privately maintained with no paid contributions accepted from any source to preserve its objectivity and integrity.


Limitations of any kind are merely future opportunities.  Not all stucco topics are discussed or presented due to time and resource limitations.  Color choices are ephemeral and are not addressed.  The water-resistive barrier (WRB) system, drainage and flashings, wall openings and penetrations etcetera – as critical as these are to an exterior wall cladding system - are not the central focus of and only receive passing attention to the extent they relate to the stucco wall cladding system.  It is hoped that many more topics will be added to as opportunities to expand allow.


Each person, by accessing is responsible to use every available means of personal and professional discretion when utilizing the information presented., its authors and referenced sources have no control over and assume no responsibility or liability for the information accumulated here, whether authored by us or others, its use or implementation, including adverse residual or collateral effects, real or imagined, for any consequential damages to any party or property, or for your safety programs, all of which are the readers sole responsibility.  Caveat Emptor.  Every reasonable effort has been given to assure the accuracy and objectivity of the information presented but there is no guarantee.  Every reasonable effort has been made to give proper attribution to contributors and sources for the information presented where it is not original material, and to respect copyrights and trademarks.  If sources were unintentionally overlooked or other errors mistakenly made, please contact me for immediate resolution.


Nothing on shall be construed as anything more than general suggestions made with good intent, are not intended for any specific stucco application, shall not be considered as recommendations that apply to any specific project or application, professional counsel or advice, and may or may not be applicable to every circumstance.  We may not agree on every point and that is both respected and accepted as reality and professional courtesy. 


Comments and suggestions are welcomed for how content may be improved and attribution will be given to anyone who submits content that improves this stucco resource. is intended to be a vehicle for a two way conversation about stucco and it is hoped that you will contact me to discuss even better stucco practices that can be included here.  If you will share stucco information with me and I include it here, I will give you attribution on


Everything else aside, the only absolute is that Minimum Stucco Industry Standards apply in all circumstances, in all regions, to all exterior stucco wall cladding assemblies.  Consultation with licensed and experienced stucco professionals is advised for any stucco-related endeavor.  Content will be periodically expanded and updated as time allows, as products and practices change and as new information becomes available, so please check back regularly. 


September 2014



Consultation with licensed and experienced stucco professionals is recommended for stucco-related endeavors.  No liability is accepted for any reason or circumstance, specifically including personal or professional negligence, consequential damages or third party claims, based on any legal theory, from the use, misuse or reliance upon information presented or in any way connected with




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