Can you hear me now?  If we’re talking about office acoustics, often times you hope the answer is “no.”  While acoustics overall can be tricky to understand and even trickier to get right in the field, there are certain conditions that have even more specific requirements requiring careful evaluation and a breadth of knowledge for proper integration into a project.  Sliding doors are one such component; when done right, they can be an effective and functional part of an acoustically performant system.  When they’re not… well, let’s just say everyone CAN hear you now.

So how do you evaluate the important aspects of a sliding door for sound performance?  That’s where we come in!  Let’s talk acoustics.

 

 

Framed Versus Frameless Systems

An important first step in determining how a sliding door might perform acoustically is understanding the system that it is operating within.  While frameless systems are attractive and offer many useful options, they are generally less acoustically sound than framed systems, and this holds even more true for sliding door systems.  Because there is no frame to accommodate any gasketing and there is necessarily a relatively large gap between the fixed and sliding elements, sound will travel through the system more easily.  While there are options to add L-shaped gasketing to a frameless system to slightly improve its performance, if acoustics are important the win here still goes to the flexibility of using a framed system with vertical framing members and gasketing built in.

 

 

Floor Leveling

While having a roughly level floor is important for pretty much any door setup, it becomes even more of a consideration for sliding doors – especially when talking about acoustic performance.  In a swing door system, the biggest concern for floor leveling is in the approximately 3′ area in which the door can swing, as the undercut on the door will have to be big enough to accommodate the high point in that area.  The same is true for the high point and undercut on a sliding door, but the area to take into consideration encompasses a much larger range of floor, as it has to include where the door will slide open as well as the space that it occupies when closed.  The more level the floor is in this space, the smaller the undercut on the door can be, which improves its acoustic performance.  Certain systems, such as Litespace or Modernus Lama with an aluminum-framed or wood sliding door, also incorporate an integrated door bottom on their sliding doors to further seal that gap.

 

Other Considerations
As you may have guessed, the most important elements to consider in a sliding door system being evaluated for acoustic performance are the places that sound has the ability to more readily travel through – basically, gaps.  These could be gaps within the parts of the system itself [as noted in the Framed Versus Frameless discussion] or gaps between parts of the system and where it is being placed [as in the gap between the door and the floor noted in the Floor Leveling section].
While these two places tend to be the problem areas for acoustics in sliding door systems, there are other factors to consider where gaps may occur.  One big one – literally – is in the meeting of the entire system to the drywall opening into which it is being installed.  As we know, having a perfectly plumb and level wall does not always happen onsite, so it is helpful to find a system that can be stick-built [that is, cut and assembled in the field in lieu of being pre-built and unitized offsite] in order to better accommodate those imperfect areas where the drywall is not completely flush.
A final, related consideration is where the sliding door itself rests when closed.  Instead of a condition where the straight line of the door is directly meeting that imperfect drywall edge, look for a system in which the door connects with a framing member instead.  A good example of this is in the Litespace demountable system, which was designed to have a fully-gasketed receiving channel that captures the closed door edge to ensure a good acoustic seal at that location.

Want to talk more about acoustics?  Have questions about gaskets?  Wondering about sound transmission class ratings?  Contact us.