Steven Wadding, RRC, RRO, CDT, Corporate Projects Manager, Polyglass U.S.A. Inc.
What is the built environment? When we talk about the traditional building, it is typically seen as a three-sided structure including the foundation or underground, the vertical walls and, our favorite, the roof. With a vast expansion of products and usages, the building is an object that has become increasingly more complex, becoming less traditional and using a wider variety of products, hence the reference to the “built environment.” Though it may still have three main areas of work, the intricacies of the building have become more complex and sometimes overwhelmingly confusing, as each area performs on its own as well as interfacing with the others.
With advancements in technology, chemistry and process improvements comes not just new products for the built environment but improvements to long-standing products we have grown accustomed to using and depend upon as contractors and professional designers. Coatings or, what is more appropriately referred to as fluid-applied materials and systems, are no exception. Great expansions and advancements have been made in this category of products. Sealants
have also seen enhancements and improvements but their uses within the built environment remain more traditional.
Though at times both membrane sheet goods and fluid-applied materials can be used in the same or similar conditions, when specifically discussing fluid-applied coatings and sealants, we generally think of the following applications and product types:
■ Waterproofing below-grade – fluid-applied (urethane, asphaltic emulsion)
■ Waterproofing plaza/between slab (non-exposed) – fluid-applied (urethane, asphaltic rubber)
■ Waterproofing (exposed) – fluid-applied (urethane, PMMA, polyurea/polyurea urethane hybrids)
■ Low slope roofing – fluid-applied reinforced systems and protective-only coatings (aluminum/acrylic/silicone, urethane)
■ Low slope flashings – fluid-applied flashing systems (silane-modified, PMMA)
■ Low slope remediation – fluid-applied (acrylic, silane-modified, silicone, PMMA)
■ Steep slope flashing/detailing – fluid-applied (acrylic, silane-modified, PMMA)
■ Metal roof restorations – fluid-applied reinforced systems (acrylic, silicone)
■ Metal roof restorations – fluid-applied protective- only coatings (acrylic, silicone, aluminum)
■ Air and water resistive barriers – fluid-applied (acrylic, STPE, silicone).
Though their use remains relatively traditional, sealants as a whole are a critical component in the control of water, moisture and air management for the modern built environment. Some may be a secondary barrier to a primary system. For example, the sealing of metal counterflashing with the roof flashings, which is the primary. However, others can be the primary barrier such as most glazing, fenestration openings and expansion joints.
A wider variety of sealant chemistry has emerged to be more specific to an application. There are still many general-purpose sealants available. Typically, urethane or silicone chemistries are used that work reasonably well. However, if you look closely, there are many specific products within these and other chemistries designed for better performance in more specific applications. This can be as simple as a better bond to a surface material type.
In previous decades, fluid-applied materials for the built environment were limited and conventional for both underground areas as well as the roof. For the exterior, there were roof coatings such as emulsions (fibered and non-fibered), aluminum (fibered and non-fibered) and acrylics. For the exterior walls, there were primarily acrylic-latex paints. For the occasional horizontal deck such as parking garages, there were urethanes. Sealants were primarily used at wall joints,
flashing and counterflashing, window interfacing and sometimes, where expansion control was needed. In a more modern built environment, many things determine the products and designs used.
As contractor’s experience in the building code world, the only real constant is change. As codes are continuously under review, adoption and implementation, contractors (and designers) are faced with the evolutionary task of staying aware of changes implemented by the authority having jurisdiction (AHJ) and, at times, without a lot of notice or public awareness. (Pro tip: FRSA members can stay ahead of the curve through its involvement in the code development process.)
Building departments and inspectors can have varying interpretations of the same code language. In Florida, this is more complicated as variations of the code exist. The high velocity hurricane zone (HVHZ) versus the non-high velocity hurricane zone, each create unique requirements that rarely overlap. Regional jurisdictions wanting to implement their own set of one standard or another for their county or city further adds to the confusion.
Though the building is still perceived by many as having three traditional areas of work, there is a growing trend of using balconies and traditional roof areas as non-conventional space. Balconies are more commonly used as occupied meeting spaces, vegetative areas or even to retain and recycle water. With this evolution of the building comes the need to rethink how traditional products are used and the implementation of a newer variety of products.
When we start at the bottom of a traditional building, we think of foundations and under-slab conditions. In the urban environment, underground parking is a popular option. Sealants, sheet and fluid-applied membranes are the most common products used for these designs. The below-grade elements of the building are, in most cases, sheet type membranes and fluid-applied materials. Sealants are most often an accessory to the waterproofing system. Foundation walls
can effectively be protected with the proper fluid-applied materials and systems once the building needs are understood. Fluid-applied materials and systems typically considered for these applications include:
■ Urethanes (hydrostatic and non-hydrostatic conditions)
■ Asphaltic emulsions (dampproofing only).
Though the roof areas using fluid-applied products and sealants are primarily horizontal in design, many horizontal areas of the building that require air, water and moisture control are not actual roof areas. Balconies, plaza decks, recreation decks and other similar designs are increasingly common in modern structures, renovations or those with an occupancy change. Fluid-applied products and sealants can be an optimal solution for such applications. Types of products range depending on many project specifics, be it the location, substrate or even performance needs. Not all fluid-applied materials and sealants are created equal and the more you research, you may find many products are best suited for specific conditions and not as a one-size-fits-all approach.
When dealing with horizontal applications that are non-roofing specific, an important consideration is its use. Will the product be exposed or non-exposed? If exposed, what kind and frequency of traffic is expected? If not exposed, how accessible does it need to be and what is the over-burden? These can be critical factors in a product and system choice for many applications.
Many such applications may require just a fluidapplied material and reinforcement but some may also require sealants or expansion control that could mean the difference between a successful application and a problematic one with call-backs. Another important concern is where sealants interface with other materials. Ensure there are no compatibility issues, because not all materials react well when they come in direct contact with each other. Some surfaces can leach when in direct contact with some sealants and stain the surface or even result in a reversion of the material after the initial set or cure.
When using fluid-applied systems on horizontal or even vertical surfaces, you need to ensure the product and system is suitable, because the performance of some materials can be limited. Is the installed material subject to hydrostatic conditions? If so, many water-based materials do not hold up well under such conditions.
Fluid-Applied materials and systems typically considered for these applications include:
■ Urethanes
■ PMMA
■ PUMA
■ Hot-rubberized asphalt.
Roofs are either low slope or steep slope and generally defined as:
■ Roofs of less than 2/12 slope are low slope
■ Roofs equal to or greater than 2/12 slope are steep slope.
With that said, there remains inconsistencies within the various industry sources, such as the various code organizations and other industry sources, as to the precise slope and definition.
There are many uses and product offerings for the built environment as it relates to roofing. Sealants are common in both low and steep slope roof designs. However, they typically serve the function of a secondary seal reinforcing the primary seal. Fluid-applied products and systems can offer a wide variety of uses in both low and steep slope roof designs. Sometimes these are used as an accessory to other materials and they can often be used as a stand-alone primary
roofing or flashing system with the proper preparation and installation. Fluid-applied systems can offer very functional and lighter-weight options when needed. This can be especially advantageous on structures with weight load concerns. In addition, options for roof recovery are more traditional materials when other systems may not be a viable option.
An ideal use for fluid-applied products and systems is metal roof restoration. Often found to have isolated or nagging water intrusion issues, replacement of a metal roof can be costly and time consuming. Fluidapplied systems can offer a convenient, cost-effective means to recover or remediate a problematic metal roof panel or similar metal panel system. Using the in-place materials as a substrate, fluid-applied systems can repair isolated leaks or offer a complete restoration system to some or all of a metal roof while adding minimal weight to the existing structure.
Fluid-Applied materials and systems typically considered for these applications (reinforced and non-reinforced depending on intended function) include:
■ Acrylics (ASTM D 6083)
■ Silicones (ASTM D 6694)
■ Silane-modified
■ Asphaltic emulsions (ASTM D 1227)
■ Urethanes
■ PMMA.
It is important to remember to make sure that the product or system is suitable for all known project conditions. Research products and systems thoroughly prior to a final decision. Be certain of the conditions: is the intent to be weatherproofing (hydrostatic) or waterproofing (non-hydrostatic)? This is critical to consider, because each requires differing levels of performance.
Always refer to the primary materials published information when considering a product and, when in doubt, contact the manufacturer to ensure the intended product and system will perform as desired. Contractors should not be expected to be a subject matter expert on everything they use, so reach out to available sources. The manufacturer should be able to answer contractor design, use and installation questions.
Steven Wadding RRC, RRO, CDT is the Corporate Projects Manager for Polyglass U.S.A. Inc. headquartered in Deerfield Beach, with current manufacturing facilities in Nevada, Pennsylvania, Florida, Texas and Arizona. His current focus is engagement in industry-related organizations serving on numerous committees, task forces and other product design and compliance activities related to roofing, waterproofing and the exterior building envelope. Steve serves on FRSA’s Codes Committee.
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