Photo courtesy of Inpro

Properly selected and specified expansion joint systems and covers can blend into a multifamily building while providing the necessary protection against building movement.

Building sections can move due to several common reasons. When it comes to expansion control in buildings, there are three types of movement that need to be accommodated:

• Thermal Forces This type of movement is most typical and caused by daily environmental temperature changes in and around the structure. Thermal movement is primarily “one-directional” in nature and is the result of the expansion and contraction of structural elements as affected by heat, cold, and humidity levels. If expansion joints aren’t put in, then thermal expansion and contraction can cause buckling of surfaces in place like roofs and interior floors.
• Seismic Activity The shifting of the earth’s tectonic plates (i.e., earthquakes, tremors, etc.), and shifts along fault lines is the source of seismic activity. Seismic movement may be horizontal, vertical, in shear, or a combination of all three. Seismic expansion joint widths may need to increase with higher floor levels to accommodate the additional, cumulative movement that needs to be addressed. When it comes to expansion joint systems, it is important to select systems that can “reset” themselves after a minor seismic event and allow workers to reposition panels easily.
• Wind-loads Movement induced by high winds, can force the structure to sway. This movement is normally perpendicular and/or parallel to the joint. This is common where a low horizontal building span meets with a taller vertical element, such as the lobby of a multifamily or mixed-use building that is adjacent to a high-rise building section. Therefore, when designing a structure, it must be able to both withstand high wind loads but also work with them. As with seismic activity, expansion joint systems should be able to “flex” and yet remain in place as the building sways or torques.

Matthew Fisher is the Expansion Joint Systems Manager for Inpro. He encourages design professionals to look closely at the way the building is going to be used by asking questions. He queries “Does the owner utilize equipment such as scissors lifts for lighting changes in high ceiling areas? Are heavy loads of furniture and dollies going to be routinely rolled over the floor for tenant move-in and move-out situations? It is usually best to ensure the worst-case scenarios are considered when specifying systems.” In his experience, a slightly higher front-end cost on the right expansion joint system may go a long way toward alleviating an ongoing facility maintenance headache for years to come.

INDOOR ENVIRONMENTAL QUALITY IN BUILDINGS

A trend among multifamily renters and buyers is to be cognizant of the Indoor Air Quality (IAQ) within and around buildings and structures, especially as it relates to human health and comfort. The general public is increasingly aware of the types of common pollutants or materials used in buildings that carry potential health risks. Therefore, architects and others in the design and construction field have increasingly been considering the following when specifying building materials:

• Red List Free Materials: The International Living Futures Institute (LFI) has developed the Living Building Challenge (LBC) as a means to design and document buildings that go beyond sustainability. They have undertaken an extensive study of materials and compounds that can be found in building products and created a “Red List” of those that should not be used if a healthy indoor environment is sought. Manufacturers can compare the ingredients in their products against this list and follow the protocol of the ILFI “Declare” labels to inform the public of the relative health safety of construction. For a manufacturer to claim its product is LBC Red List Free, it must first disclose 99 percent of ingredients and residuals present at or above 100 ppm or 0.01 percent. The product may contain one or more Red List chemicals, but only if covered by an established exception. More information is available at: https://living-future.org/red-list/
• Certified Low VOC Emissions: Volatile organic compounds (VOCs) (including formaldehyde), are substances that are potentially emitted from building materials that can adversely impact human health. It is often found in materials that contain binders, glues, adhesives, coatings, and the like. The good news is that many products are now available with reduced levels of VOCs or, even better, are formulated to be VOC-free. The US Green Building Council has included a focus on low VOCs in all versions of the LEED green building rating system and is a good resource for more information on this topic. https://www.usgbc.org/credits/new-construction-core-and-shell-schools-new-construction-retail-new-construction-data-38
• Non-Detect Asbestos: From the 1930s to the 1980s, asbestos-based drywall was popularly used in residential, commercial, and industrial structures. Beyond the individual drywall sheets, joint tapes and compounds also incorporated asbestos additives. While this material had great fire resistance properties, it also exposed building occupants and construction workers to a serious health hazard when the asbestos fibers became airborne and were inhaled. In response, asbestos is no longer permitted for use in drywall sheets, tapes, and joint compounds making them much safer to use today. As a matter of enforcement, U.S. Government agencies conduct thorough investigations of gypsum plants to determine if any asbestos is detectable in their products. Those that prove they use only naturally occurring gypsum, and no asbestos in their products, receive notice that no asbestos is detected, and their products are safe to use. For renovation projects it may be helpful to refer to: https://www.airpf.com/identifying-sheetrock-asbestos-what-does-asbestos-drywall-look-like/
• Respirable Silica: A more recent focus has been on the health hazards of silica dust which can be inhaled. Prolonged exposure to silica can lead to serious health issues such as silicosis, lung cancer, and other respiratory diseases. Silica testing can determine if dust contains crystalline forms of silica (quartz, cristobalite, and tridymite) that may cause silicosis, lung disease, or is a known carcinogen to humans. It is therefore recommended to follow good work practices to minimize dust generation from all building products, including gypsum products. Industrial hygiene tests are also recommended to determine the actual exposure at the worksite due to the inherent variability of each project.
• Mold Resistance: Mold has the potential to cause health problems since it can produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins). Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals. Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis). Mold-resistant gypsum panel products provide enhanced protection against mold and moisture in areas such as kitchens and bathrooms.

Acknowledging the causes of indoor air quality issues and specifying the appropriate gypsum board products to address those issues can go a long way toward preventing potential health issues for everyone involved in multifamily housing. Given all of these attributes, it is not surprising that gypsum has become the material of choice for many multifamily buildings. Deborah Callaway, Manager, Technical Services, at PABCO Gypsum has been directly involved in working with architects and construction professionals on many multifamily buildings. She observes that, “A full variety of gypsum products are available to provide solutions to the many challenges inherent in multifamily construction. Whether acoustics, fire protection, or indoor air quality, gypsum panels can meet those needs that are important for a comfortable and safe space.”

Photo courtesy of PABCO Gypsum

Manufacturers who complete an extensive review of the ingredients in their products can strive to avoid any items on the Living Building Challenge “Red List” to create healthier indoor environments.

CONCLUSION

Creating well-designed, sustainable, and comfortable multifamily housing is a multi-faceted task. Interiors need to be attractive and durable, including the interior of elevators. Gypsum board should be specified to match the varied needs of acoustic control, fire protection, and indoor environmental quality. Innovative materials like aluminum trim can be used to enhance the building’s exterior and interior. Large buildings require expansion joints to protect against inevitable movement. The strategies discussed in this course can help architects and designers address these multiple design criteria to meet the needs of the building owner, the occupants, and the environment.

Acoustics Case Study

Photos courtesy of PABCO Gypsum

Project: Santa Clara Square
Location: Santa Clara, California
Owner: The Irvine Company
Community Master Plan: Pei, Cobb, Freed and Partners
Apartment Buildings Architect: MVE + Partners
Acoustical Consultant: Veneklasen Associates

The Project: Santa Clara Square is an expansive mixed-use community with 1,847 high-end apartments spread over seven buildings. It combines innovative office space, vibrant dining and shopping, and modernized living all in one integrated community. Winner of Silicon Valley’s Milestone Project of the Year Award, Santa Clara Square combines the best elements of a lively cultural center and a sophisticated technology hub, creating a forward-thinking community unlike anywhere else.

The Challenge: The design focus was on providing units that were as quiet as possible for the wood-framed building structures, according to Jeff Troy, Vice President, Quality Assurance, Irvine Company Apartment Development. To accomplish this, the company put together higher acoustic standards for walls and floor/ceiling construction than agencies and other builders require. The following were the goals set forth for the project:

• Airborne Noise: Normalized Noise Isolation Class (NNIC) performance of 58, a similar measurement as STC but in a field setting
• Structure-borne Noise: Normalized Impact Sound Rating (NISR) of 58 with a Low-Frequency Impact Sound Rating (LIR) of 50 and a Normalized High-Frequency Impact Sound Rating (NIHR) of 65

The Solution: Working with the acoustical consulting firm Veneklasen Associates, they were looking for building solutions that would achieve these higher performance requirements. John LoVerde, FASA, Principal, Veneklasen selected acoustical gypsum panels for the floor/ceiling solution. The 3/4″ thick gypsum panel was used on all floor/ceiling assemblies where there are hard floors typically in the kitchen and main living area in addition to the amenity spaces next to the units.

Along with the acoustic panels, Type X and Type C as well as 5/8” mold inhibiting and shaftliner panels were used on the project. According to the drywall subcontractor, about 85% of the total 10 million square feet of drywall used for Santa Clara Square all came from the same manufacturer. This expedited construction and made it much more convenient for the drywall contractor.

Beyond the building materials used, a Quality Assurance program was put into place to ensure that the desired acoustic results were achieved. The project team held preconstruction meetings before every new building phase began by explaining the expectations. Once the project was started, the QA team was on the job every day watching the execution. In addition, Veneklasen wanted to make sure that there were no conflicts between fire and sound so he conducted 250 tests on the walls and floors to confirm the acoustical performance required.

The Results: As a result of the QA program and working closely with Veneklasen on testing, the project has been very successful according to Troy. “We were very satisfied with the acoustic results we achieved which are better than most in the industry,” he said. In fact, the results achieved were higher than originally expected for three out of the four goals, according to LoVerde.

Image courtesy of PABCO Gypsum

What is most important however is tenant comfort and satisfaction. “Not hearing your neighbor walking back and forth above or playing a guitar was key for us,” Troy said. “We’ve had no resident complaints and the project team we worked with had a lot to do it with it.”

Peter J. Arsenault, FAIA, NCARB, LEED AP is a nationally known architect and a prolific author advancing positive acoustical experiences through better building design. www.pjaarch.com, www.linkedin.com/in/pjaarch