The Air Under There: Best Practices for Successful Raised Floor Installs

By David Atwood, General Manager at Integrated Interiors

Raised flooring and underfloor air applications have quickly risen in popularity with the new demands of sustainable construction. With benefits tied into both its efficiency and indoor air quality (IAQ), modular construction of underfloor air applications will become a key differentiator for any general contractors familiar with the benefits and the challenges of installing raised flooring systems.

Start at the Top

Perhaps the most unorthodox part of any raised floor system is the sequencing of the various trades.  Contrary to conventional installations where HVAC systems are contained in ductwork above the ceiling, raised floor systems are designed to incorporate most major building systems within the confines of the floor cavity.  Therefore, what remains in the ceiling – sprinklers and lighting systems – needs to be completed first, as well any other overhead work, to ensure floor installation and the sensitive systems within can be installed without any interruption or risk of damage.

In addition, when critical building systems are located underfoot, and bringing staging, lifts and other equipment for ceiling installation would only serve to complicate the installation of the floor.  The most effective way to manage floor construction is to phase the various trades effectively, starting with fire protection and lighting systems to ensure all overhead work is completed first.  By educating the subcontractors and providing a clear understanding of what phase each trade will be involved with, general contractors can capitalize on the efficiency of raised floor systems.

Keep the Airways Clear

One of the biggest advantages to underfloor air applications is a reduction of approximately 80% of the ductwork found in conventional projects with standard flooring.  With the floor containing air distribution chambers, it’s critical to ensure that all subcontractors know to keep the area beneath their feet as clean as possible.  When overhead work is completed, work with the electrical and mechanical trades should begin to configure the building’s power distribution systems and HVAC passageways.

It’s important to note, however, that the floor is laid out in a grid formation, utilizing a 10×10 spray-painted dot grid throughout the entire floorplate.  These dots identify locations where the pedestals are located, which are components that support the load of the floor and cannot be altered.  Lack of coordination between trades can lead to installation of piping, electrical systems and cabling in places that conflict with pedestals and can only be rectified by building a structural support to sidestep the interference, leading to delays and additional costs.  Given the relative newness of raised flooring systems, education of the trades is critical to avoid costly missteps.

In order to maintain the integrity of the airways, walls surrounding the underfloor chambers need to be sealed as tightly as possible, allowing for zero penetrations in the design.  As the underfloor cavity acts as a delivery plenum, any gaps or openings can lead to expensive and frustrating air loss.  Teams should also understand that any drywall verticals, whether columns or walls that extend down into the floor, are also critical to the air delivery system and should be carefully integrated into the flooring systems and properly sealed at the slab.

Following the Order of Operations

In one of the most critical phases of any raised floor installations, mechanical, electrical and flooring trades must work together to ensure each system is properly routed up from the slab and through pre-drilled openings in the floor panel.  A few additional steps have to happen first, however, before the raised floor is installed.  Raised flooring uses a modular power system, with zoned distribution boxes and power cabling mounted in the slab and data lines contained in cable trays alongside the utilities.  Once floor installation begins, all remaining materials are staged above the raised flooring to effectively float over the power and data equipment and avoid working directly on top of cabling.

Next, mechanical trades must be brought on board to lay out mechanical boxes and diffusers.  Diffusers are brought up and installed within the floor, and power and data cabling are guided through pre-cut openings in the floor panel.  Prior to purchasing materials, teams should outline exactly how the floor panel will accommodate the project’s power and data systems in order to secure a panel design with the proper penetrations already made.  Most raised floor systems use standard 2×2 panels with cutouts according to the specific project needs.

Once all systems have been tied in and tested, carpet installation begins.  Installing carpet in individual rooms is incredibly streamlined over conventional approaches, as carpet consists of individual modules matched to an access floor panel.  This means no more tedious cutting and measuring each section as the entire floor is essentially installed in one piece and must be done prior to any walls being constructed within a conventional modular interior.

Even in the final phase constant reinforcement of the basic principles of raised flooring must be emphasized among the trades, including that any subsequent penetrations in the drywall should be sealed at the slab level to preserve the integrity of the systems below the surface.  However, with a proactive approach to educating the team and a coordinated approach to installing building systems, general contractors can offer clients increased flexibility and enhanced sustainability for a wide range of applications.

Please contact us for more info about underfloor air.
Learn about UFAD projects we’ve completed:

• Partners Healthcare (in progress)
• Edward M. Kennedy Institute
• Massachusetts Green High Performance Computing Center (MGHPCC)
• Apple (Haworth, Inc.)
• ExxonMobil (Haworth, Inc.)

 

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About the Author

David Atwood is the General Manager of Integrated Interiors, New England’s premier commercial architectural/engineering products and construction services company. Integrated Interiors provides architectural interiors products including moveable walls, raised flooring, and modular power, as well as design-build construction services for mission critical or data center environments. The company is the region’s only source for the integrated procurement and installation of modular architectural products through a single manufacturer – Haworth. Combined with Haworth’s Organic Workspace™ products, Integrated Interiors’ modular solutions provide flexible, high performance workspace that adapts to companies’ changing needs while meeting the growing demand for sustainable and LEED-supportive design.  For more information, go to www.iiawne.com.

Article originally appeared here.