Words: Chris Bettinger, Masonry Association of Florida Board of Directors, Masonry Association of Florida ProMasonry Chairman, Architectural – Commercial Sales Specification Representative
Photos: Bradley Masonry
I had a choice in writing this article. Should I focus on masonry specifications, strengths, and tolerances or, the inspiration masonry finishes can offer? There have been many articles written that prove the performance values and case studies that confirm masonry’s resiliency in the field. All of them are technically sound and great representations of our industry. I’d rather focus on the aesthetic. Architects are driven by the aesthetic. If we can give a designer the “look and versatility” they’re after without sacrificing resiliency, masonry shines. Let’s consider masonry resiliency from the aesthetic point of view.
How does masonry fit in?
Every design is a balancing act for an architect between qualifying and quantifying the needs and the wants of their client. We can’t forget the budget. How limiting is it? Will it kill the design aspirations of the owner and design team? I recently came across this quote from one of the most innovative and recognized architects over the last 50 years speaks to the motivations in developing a design…
“Architecture is really about well-being. I think that people want to feel good in a space … On the one hand it’s about shelter, but it’s also about pleasure.”
– Zaha Hadid
Well-being is a broad term. When applied to the end-users of a commercial building, what does well-being mean? Shelter for people and equipment? A happy, healthy and productive environment? Again, these are broad terms, but still appropriate.
What is implied by the term pleasure? Pride in your building, your image – what does the building say about you? Does it make you happy? Those are certainly factors to consider. But, peace of mind is important also.
Design intent is the architect’s vision of the building at its grand opening and throughout its design life. A fifty to seventy-five-year design life is typical for most buildings. How will a project show its age? How will it stand up to the challenges of seventy-five years in use? In a perfect world, we would like to walk up to a project after fifty years and have it look as fresh as the first year. To achieve this, we understand maintenance is required – but it needs to be at a reasonable cost. Masonry requires minimal maintenance to maintain its intended appearance.
Masonry’s challenge as an industry, is to show its versatility and how it balances the aesthetic requirements and resilient needs of a project over its life. Masonry’s resiliency is key to meeting these goals. Exceptional performance against the elements is its strongest asset – protecting against water, wind, mold, bugs and fire. However, masonry’s benefits go well beyond that, offering plenty of aesthetic choices for any project. Sometimes masonry’s aesthetic opportunities are forgotten. The masonry materials listed below are all resilient, colorfast, durable wall systems that have been proven over time.
How does CMU fit in?
Concrete masonry units (CMU) give a structural backbone to a project without sacrificing the design intent. Typically laid in an 8” or 16” module, reinforcement is easy without limiting articulation in design. This flexibility gives designers options creating depth in the wall by offsetting features, thereby creating interest and character. Scale can vary, typical heights of either 4” or 8”. Production methods have improved expanding size options and units are available up to 24” long. Units in a single-wythe application will not limit design choices. Multiple textures and colors add to those options. Coloring concrete with natural oxides provides color-fast performance over time. Split face, smooth face or ground face finishes can create traditional to ultra-modern projects. Aggregate choices can highlight the texture or accent the body color. Stucco is a traditional finish over single wythe CMU that is as versatile as any finish available.
How does Thin Veneer fit in?
Admittedly, single-wythe masonry may not be for everyone. CMU as your structural element gives you the performance you need. What can we put over the CMU back-up? Go thin, over the last 10 years thin veneers have gained popularity. There are a multitude of choices ranging from brick, stone and artificial stone. The sizes vary from ledgestone to modular brick to large oversized decorative units. Thin veneers perform best over a stable rigid sub-straight. When installed on CMU with a polymer fortified setting material, thin veneers perform very well. Drainage planes can be established to manage water, further improving the walls performance. Thin veneer installation is quick, saving money on your labor. Thin veneers also provide more choices without sacrificing resiliency.
How does 4” Veneer fit in?
Single-wythe is a great option! Thin veneer over CMU provides even more choices! However, why not consider “The Perfect Wall”?1 Double wythe construction has been proven over time to be the most resilient wall system. Introducing a 2” airspace between a 4” veneer and your structural 8” CMU back-up changes everything. The airspace is neutral. Water and water vapor are the number one problem in construction. The neutral space establishes a drainage plane and lets gravity take moisture away. Water gets in, then travels down through the neutral space over the drainage plane and out the weeps. Insulation is best outside the interior of the building, putting it in the airspace to protect it allows it to do its job. These factors promote the efficiency and resiliency of the wall and the health of the structure. What are your choices for the 4” veneer? Clay brick, full bed stone or architectural CMU. All offer numerous choices in color, texture and scale. All are colorfast and durable.
Another, often-overlooked design element to consider is mortar. A good example of this is that with a modular size brick, mortar comprises 20% of the wall area. A simple change in mortar color can dramatically change the look of a wall. Traditional brick with a range of colors can act like a chameleon because of the mortar color accenting a tone in the brick. (See figure 1 below) This is a simple change with little impact on the budget but a dramatic change in the look of the brick. Mortar is also colored with natural oxides making it colorfast over time. Additionally, mortar is offered in pre-blended bags allowing the mason to add water and mix. Controlled production limits impurities from sand that can change mortar color and performance over time.
This conversation started with the priorities and choices architects have. Masonry is sometimes considered an “old fashioned” material – a great system but limited in choices. How do we change that? We can’t take the durability of masonry for granted. We also shouldn’t discount the wall system and finish options. It is important to consider all available options. A great place to start a truly resilient design is with the CMU structural element. CMU is proven over time and versatile in its abilities. Single-wythe is a good option with a finish integral to the block and either a split, smooth or ground face. Thin veneer over CMU and double-wythe construction offer multiple options structurally and aesthetically. Masonry can satisfy most design intents without sacrificing resiliency.