Three Items to Consider When Specifying a Sliding Hardware System

It is important that the sliding hardware system specified onto a project be capable of delivering both the expected functionality and the desired aesthetic appeal. To that end, there are three critical decisions that must be made when selecting the best sliding hardware system for any specific project. The system must be specified as either a top-hung system or a bottom rolling system. If glass panels will be the material used in the system, the architect must decide whether to use machined glass or non-machined glass. And finally, the mounting methodology must be selected.

In top-hung systems, the top track supports the weight of the panels. Image courtesy Hawa Americas Inc.

Top-Hung Systems vs. Bottom-Rolling Systems

Both top-hung and bottom-rolling sliding systems are comprised of the same basic components. The difference between the two systems is where the weight of the panels is supported. In top- hung systems, the top track supports the weight of the panels. In bottom-rolling systems, the panel weight is supported by a track in the floor.

Top-hung systems can provide a smoother movement more reliably, can accommodate curvilinear movement and curved panels, and offer an overall cleaner aesthetic, but top-hung systems do have load capacities that can limit the size and weight of the panel materials used. The more reliably smooth operation is a product of the type of track used in top-hung systems and the use of the ceiling, instead of the floor, as the foundation for the track. Some top-hung systems employ the box type track ensuring that the trolley remains in contact with the track at all times and eliminating the possibility that performance will be impeded by the trolley jumping the track. And since the top-hung track is mounted on the ceiling, the rolling action of the system is not affected by unlevel floor conditions. In terms of cleaner aesthetics, top-hung systems can be concealed into the ceiling, leaving no visible sign of the mounting hardware, and they do not require a bottom track, allowing for the space to maintain a clear threshold.

Top-hung system load capacities will differ by manufacturer and panel material, so when specifying a sliding hardware system, please be sure to check the load capacities of the specific system being considered. For illustrative purposes, here is a general range of top-hung system load capacities by panel type. A top-hung system can support a glass panel weighing between 88 lbs. and 1100 lbs., a wood panel weighing 88 lbs. up to 1100 lbs., a metal panel weighing between 176 lbs. and 1100 lbs., and a combination glass and wood furniture panel weighing from 33 lbs. up to 176 lbs.

A bottom-rolling system provides a very high load capability, allowing for very heavy or very large panels to be used in a space, without requiring complex hardware for support. In a bottom-rolling system, a bottom track is surface-mounted or mortised into the floor and the panels open and close by rolling along that bottom track. The location of the track in the bottom-rolling system can create some functional and aesthetic issues that a specified should be aware of. There is also the possibility that the rolling elements of a bottom rolling system will jump the track, affecting performance. Aesthetically, these systems do require a track to be placed in the floor, which will be visible, and the rolling movement can be impaired if the floor track is contaminated or blocked. Bottom-rolling systems are also susceptible to uneven floor surfaces, which can cause the system to tilt in one direction or the other, if not correctly leveled.

Machined Glass Panels vs. Non-Machined Glass Panels

If glass is selected as the panel material for a sliding hardware system, the designer or design team will need to choose between installing a machined glass panel or a non-machined glass panel. There are essentially two ways to mount a glass panel into an architectural sliding system. One is to drill holes or cutouts into the glass, a process called machining, which enables the mounting mechanism to be stuck through the glass panel and attached to the system. The other way to affix the glass panel to a sliding system is to select a clamp-style mounting where the mounting hardware clamps onto the glass, holding it in place.

While the clamp will mount a glass panel that has not been machined, or non-machined glass, there is a risk of the glass falling out of the clamp as the prolonged movement of the system combined with the weight of the panel can cause the glass panel to shift and vibrate. With machined glass, the mounting hardware does not physically mount to the glass, but instead attaches to the mounting mechanisms that have been slid through the holes or cutouts that have been machined into the glass panel.

Panel-Specific Mounting Options

The way that a panel is mounted to the architectural sliding system will determine whether the mounting hardware is seen or concealed and where the hardware is located. Mounting options are unique to the type of panel material used in the system, so there are different options depending upon whether the specified system is wood, metal, or glass.

Wood Panel Mounting Options

Wood panels can be mounted to a sliding system with a top recessed mount, a top mount or a side mount. A top recessed mount allows the hardware to be concealed in the top edge of the door panel. The hardware will be visible in both the top mount and side mount options. Top mount hardware is mounted and visible on the top of the panel and side mount hardware is mounted on and visible on the inside of the panel.

Metal Panel Mounting Options

Metal panel mounting options are very similar to the wood panel mounting options just described. These panels are typically mounted on either the top of the panel or the side of the panel.

Glass Panel Mounting Options

When specifying a glass panel for a space, transparency is often an aesthetic objective of the design team. The type of mounting selected will impact whether or not the mounting hardware is fully concealed or visible and to what degree.

The type of mounting selected for a glass panel system will determine if the mounting hardware is fully concealed or visible and to what degree. Image courtesy Hawa Americas Inc.

Frameless

In a frameless mounting, the hardware is fully concealed in the track, preserving the transparency provided by the glass system. This mounting style requires machined glass and can be used with either tempered or laminated glass.

Patch Fitting

The patch fitting mounting style requires machined glass and provides minimal hardware exposure. This mounting option can be applied to both tempered and laminated glass.

Suspension Profile

In a suspension profile mounting, the suspension hardware is hidden behind the cover profile and minimal hardware is exposed. This mounting style also requires machined glass.

Framed

The framed mounting style frames the glass panel on all four sides and provides rigidity for tall glass panel applications. This style does not require machined glass.

Friction Clamp

A friction clamp mounts glass panels without requiring that they undergo the machining process. This mounting option is not suitable for panels that weigh more than 220 lbs. and is not recommended for use with laminated glass.

Hawa Americas Inc is the U.S. subsidiary of Hawa AG, a Swiss company renowned internationally as a specialist and leading manufacturer of innovative sliding hardware. Hawa systems can be seen at some of the best addresses in the world. The company has a high-quality solution for virtually any requirement, any material and any door weight, from sliding doors for furniture and buildings to sliding shutters and highly complex sliding wall systems. Over the past forty years, Hawa has developed a multitude of technically high-class systems for folding, sliding, or stacking doors and walls made of wood, glass and metal. www.hawa.com