August 2013: Core Configurations

Whether it’s yoga or room configurations – everyone wants flexibility. Operable partitions fill that need in architecture; they provide the flexibility to re-configure rooms and make a building more versatile. They are used everywhere from conference facilities to church halls, ballrooms to classrooms, and gymnasiums to theaters. But there are limitations as to how much acoustical isolation operable partitions can provide. Read on to learn more about the proper deployment of these building components.

How do they rate?

The rating system most commonly advertised for operable partitions is the STC (Sound Transmission Class). This single-number rating describes how effective an assembly is at reducing sound through it; the higher the number, the better the isolation. The STC is a laboratory rating, which does not necessarily translate to the field, particularly for operable assemblies. The NIC (Noise Isolation Class) is a field rating. It is similar to the STC but accounts for all the other conditions that exist in field installations. Most manufacturers of operable partitions will say that the NIC rating will be 10 points lower than the advertised STC rating. For decent speech privacy, the field rating should be no lower than NIC-40.

So many choices!

There are many different types of operable partitions. Some are intended for purely visual or physical separation; some provide good acoustical isolation. Accordion style partitions do not provide good acoustical isolation. Panel type partitions, whether they are stored in a wall pocket or dropped down from the ceiling, provide better isolation because of their more massive panel construction and superior gasketing. Since panel type partitions generally have thicker edge conditions, their gasketing systems form better seals.

Modernfold Partition Wall Pic

Example of a panel type operable partition (Modernfold)

It’s all in the gaskets.

The perimeter sealing systems of operable partitions are what usually make or break the isolation they provide.

Example of separation at bottom of panels

In the lab, everything is adjusted perfectly for the STC tests, but out in the field, there is less control. Most of the problems we encounter with operable partitions are due to improperly adjusted perimeter gasketing, which will leave gaps where sound can leak through. It is imperative that the gaskets are properly adjusted at installation and maintained regularly. We have measured differences of up to 10 NIC points on the same operable partition before and after gaskets were adjusted.


Example of an unadjusted bottom gasket







Expectations-very important.

User expectations of acoustical properties are the most important part when specifying operable partitions. Even if a partition is properly installed and provides a field rating of NIC-40, you will still be able to hear elevated or reinforced voices through it. The end users must be fully educated on what to expect when an operable partition is installed.

 Example of Operable Partition Photo

Example of a meeting room operable partition (Modernfold)

Operable partitions can be very useful in a building provided they are between areas that are compatible or not particularly noise-sensitive. Like yoga, they provide clients flexibility and strengthen the “core” functions of a room. However, we don’t recommend using partitions between an aerobics and yoga studio!

September 2013: Batter Up!
July 2013: Not Just Another Brick in the Wall