The Next Step: Before You Install a Glass Floor

By Ellen Rogers

Glass floors and stairs have become a highly in-demand aesthetic feature in a variety of commercial and high-end residential applications. Thanks to developments in fabrication products and technologies, architects and designers have a vast selection of options when it comes to creating unique glass floors and stair treads. While the design possibilities may be nearly endless, installing floors and stairs comes with a few important considerations. The work isn’t overly complicated, however, it’s important to keep in mind that installing a glass floor isn’t like installing a window.

Installation Considerations

Mark Maixner is the owner of MTM Glass and Metal. With operations in Caldwell, N.J., and Murrells Inlet, S.C., he has been working in the glass industry for 30 years, and installing glass floors for about six. Maixner says he’s known and worked with Wayne Conklin, owner of Glass Flooring Systems Inc., for many years. It was Conklin who got him started in this segment, shortly after launching his company.

Conklin explains his company’s systems are fully structural and typically don’t require additional supports such as steel.

“This makes for ease of installation. No welding of any type is required. Framing materials bolt together on site and are pre finished. Our setting gasket is fitted to the frames and makes for an easy prep prior to setting the glass,” says Conklin. “Because all systems have been fully built [in the shop] reassembly on site is easy for the installer.”

Speaking of differences compared to vertical glazing, Maixner adds, “It’s just a whole different entity.” One consideration he points out is that glass floors are often heavier than vertical glass applications. This, he says, means special handling and lifting equipment is needed.

“When it’s over 400 pounds you need some type of system to maneuver and install the glass,” he says. “The spans on every job are different.”

Before joining New Hudson Facades in 2016, Steve Murrow was a glass project specialist with M. Cohen & Sons, and was involved with many glass flooring projects. He says a number of visual considerations are important to keep in mind.

“The most overlooked consideration is seeing the setting blocks/gaskets through the glass. You either need a solid border on the glass to prevent seeing hot spots through it or you need to make sure that your setting material is consistent and presents a pleasing aesthetic,” he says. There’s a variety of options, but ceramic frit, silicone opacification and even vinyl films can be used to prevent seeing the glass setting material below.”

In addition, Murrow notes that some type of protection is needed to help keep dirt or debris from ending up along the sides or underneath the glass. This can be, for example, pile stripping that adheres around the edges of the glass/frame, or a press-in gasket.

“You can use a silicone and caulk it in there. But when caulking clear floor glass you have to be mindful that you can see through it. Your perimeter caulking should be at a constant depth for aesthetics,” he says. “You want to make sure there is nothing unsightly with the installation. Looking through the glass and seeing an uneven caulk joint would be an eyesore.”

It’s also important to ensure that if the sealant comes in contact with the laminated glass interlayer the two are compatible. Murrow says standard practice for material compatibility should be used. He adds that since this glass is meant to be walked on, it will be subjected to pressure and forces in all directions, “almost as if it will have to endure seismic movements.”

Florian Doebbel, business development manager, façades at Sika, says incompatibility between the sealant and interlayer can lead to discoloration, loss of adhesion, as well as loss of mechanical strength properties. His company offers testing with laminated interlayers to ensure compatibility.

Visual Aesthetics

Murrow says glass flooring and stair installations often begin as design-build
projects, where the architect or designer engages the installation company for input. But whether design-build or not, there are certain aesthetic considerations on which installers can provide guidance. For one, transparency.

“A glass floor has to have an anti-slip surface,” he says. “This can be a cast glass top lite in a multi-layer laminate. There’s also an acid etch which provides opacity, so you can’t see through it, but it’s still translucent.”

Murrow adds that, in many of these installations, particularly those with stair treads and floor landings, there may be exposed edges, so the composition of the glass is really important.

“You want multi-layer annealed laminated glass when you can, because then you can have beautiful post-laminated polished edges. When the glass is heat-treated/tempered it has to be polished before heat-treating and laminating, so it’s important to work with a glass company with tight fabrication tolerances to reduce edge slip.”

Ready to Start?

For contract glaziers interested in adding glass floors and stairs to their installation capabilities, the work isn’t overly complicated, but does call for attention to detail and focus.

“Do a mock-up. If you want to get into this you can incorporate it into your own facility to help prove out their design concept,” says Murrow. “There are all kinds of ways to install glass floors.”

Maixner adds that while the process isn’t overly complicated, it’s probably not something a company without glass installation experience would start.

“You don’t get into it unless you have a background in glass,” he says. “It’s a fun thing to do. Anyone with experience in the business could pick it up easily.”

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