Over the years, we have experienced various situations when coordinating the finish hardware with sound assemblies. It is not our intention to change the intended design of the project, but to point out that certain hardware combinations may compromise the effectiveness, or usefulness of the acoustical product.
In order for Stiles to certify the STC rating of an assembly, it must be fabricated as tested by a certified acoustical laboratory. Our doors have a factory supplied door bottoms and frames have factory applied perimeter seals. Neither item is designed to have hardware, nor any other item attached to it.
Before manufacturing can commence, there must be a review of the hardware schedule to see if any of the following problems could potentially occur. We have found that the best time to do this review is at the time of submittal / when shop drawings are prepared. If, during this review, potential problems are discovered, the draftsperson can explain them in an RFI, outlining possible solutions. A disclaimer on all proposed possible solutions should be included. Stiles has trained acoustical associates ready to assist you in every manner.
| DESCRIPTION | POTENTIAL PROBLEM | POSSIBLE SOLUTION |
|---|---|---|
| LOCKS | ||
| 1. Cylindrical Lock with knob handle | PS1 Perimeter seal is 1-3/32" high, and therefore a lock with a 2-3/4" backset and a knob handle is too close to the seal and may cause hand injury |
1. Change to a lever handle 2. Change to a 3-3/4" backset |
| 2. Mortise Lock with Knob Handle |
They are available with a 2-3/4" backset only, and may cause hand injury |
1. Change to a lever handle |
| 3. Rose Size | PS1 perimeter seal is 1-3/32" high. If the rose is larger than 2-1/2" in diameter, it may hit the seal, thus preventing the door from closing. May also cause a hand injury. |
1. Change to a Rose no larger than 2-1/2" in diameter |
| PANIC / EXIT DEVICES | ||
| 1. Concealed Vertical Rod type Panic Device (i.e. Von Duprin 8847) |
This device requires that the interior area of the lock edge be open the full height of the door. This eliminates some of the sound retardant core and may effect the sound performance of the assembly |
1. Increase the STC rating to compensate for the possible loss 2. Change to a surface mounted vertical rod |
| This device does not allow for the use of a mortised door bottom. | Change to a surface-mounted door bottom (i.e. ADB5) |
|
| 2. Surface Mounted Vertical Rod type Panic / Exit Device (i.e. Von Duprin 8827) |
The latch at the head is mounted on the frame soffit in the same area where the sound seal is located. The sound seal is not designed to have the latch mounted on it. Also, if the seal is cut to permit the mounting of the latch, the sound seal will leak. | The surface applied latch should be mounted on a "Z" bracket (furnished by Stiles) at the head, NOT on the sound seal. |
| 3. Rim Type Panic / Exit Device (i.e. Von Duprin 88 or 99) |
This device requires that the surface-applied latch be mounted on the frame soffit or on top of the sound seal. This interferes with the sound seal. The sound seal is not designed for this. | Change to a mortise type device where the strike is mortised into the rabbet area of the frame; not the soffit / stop. |
| 4. Panic / Exit Devices on door pairs with an overlapping astragal | An overlapping astragal is required to achieve the STC rating. If both leaves are active, as is the case when panic / exit devices are used, the astragal can prevent the doors from closing properly. | Add a door coordinator. |
| CLOSERS | ||
| 1. Parallel Arm Closers | This type of closer is generally mounted on the frame soffit, which will interfere with the sound seal. | 1. Mount the arm bracket behind the sound seal. 2. Change to a top of jamb mounted closer. |
| 2. Concealed Overhead Closer | This type of closer is mortised into the head of the frame, and interferes with a portion of the sound seal that will cause a sound leak. When Cam Lift Hinges are required, they move the door up and down as the door opens and closes. A concealed overhead closer does not have a knuckle that will permit this type of movement. This could cause excessive wear to closer, while greatly reducing its service life. |
1. Change to a surface-mounted closer. 2. Change to standard hinges, which do not move the door up and down; change to an automatic door bottom. |
| 3. Rixon Floor Closer | This type of closer is mounted into the bottom of the door, preventing the use of a mortise door bottom. | 1. Change to a surface-mounted closer. 2. Change to a surface-mounted door bottom. |
| FLUSH BOLTS | ||
| 1. Flush Bolts | The bottom flush bolt operates through the bottom of the door, preventing the use of a Mortise automatic door bottom. | Change to a surface-mounted automatic door bottom. |
| THRESHOLDS | ||
| 1. Fluted, Grooved, or Abrasive Finished Thresholds | These thresholds can cause sound leaks. | Change to a smooth metal threshold set in mastic. |
| 2. Carpet underneath the door or underneath the threshold | When carpet runs under a door or threshold, a sound leak may occur. | Install a smooth metal threshold set in dense mastic under the door, with the carpet butting up to it. |
| MULLIONS | ||
| 1. Hardware Mullions | Mounting bracket interferes with perimeter seal. | Change to a Von Duprin 9954 Removable Mullion. The mounting brackets are much less intrusive. |