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Understanding SCIF Requirements for Acoustics: Avoid Costly Mistakes

  • Writer: Phil
    Phil
  • Feb 18
  • 2 min read

A SCIF or SAPF isn’t just about physical security—it’s about protecting conversations from prying ears. To ensure confidentiality, facilities must meet strict acoustic protection standards set by the Accrediting Official (AO). The ICD 705 Technical Specifications (Tech Spec) outline the requirements and mitigation strategies to prevent sound leakage. Here’s what you need to know to get it right the first time.


Green Sound Waves on Black Background
Sound Waves

SCIF Requirements on Acoustics & Mitigations

The AO will determine the Sound Transmission Class (STC) rating based on whether amplified sound will be used inside the facility. The two standard ratings are:

  • STC 45 (Sound Group 3): Loud speech is heard but not understood; normal speech is inaudible outside.

  • STC 50 (Sound Group 4): Even a loud radio or trumpet is barely audible outside.

To meet these ratings, the facility’s perimeter walls serve as a primary acoustic barrier. The Tech Spec suggests three wall types, all emphasizing a multi-layered approach:

  • STC 45: Three layers—one on the unsecured side, two on the secure side.

  • STC 50: Four layers—two on each side.

Walls must also be insulated, and insulation must be mechanically fastened to prevent sagging, which can compromise acoustic integrity. Acoustic sealant is essential for closing gaps.

While the Tech Spec provides guidance, it’s not prescriptive. Alternative materials like concrete may be used if they meet the acoustic requirements and are AO-approved.

Penetration points—such as pipes and HVAC ducts—require special attention. Pipes should be fully sealed with acoustic sealant, while HVAC systems can use Z Ducts or sound baffles to maintain sound integrity.

Common Acoustic Mitigation Mistakes

  1. DIY Door Assemblies: Contractors sometimes mix and match components instead of using a pre-assembled STC-rated door system. Even if all parts meet STC ratings individually, the assembled door may not perform as expected.

  2. Improper Door Installation: Even with a door-in-a-box system, improper installation can ruin effectiveness. The seal must be applied thoroughly around the entire frame.

  3. Weak Sealant Application: Acoustic sealant is critical for pipe penetrations and wall seams. A sloppy job here can create vulnerabilities that lead to accreditation failure.

Supplementary Mitigations

Even if a facility meets STC requirements, the AO may require additional measures, such as:

  • Sound masking systems: White noise or sound transducers mask speech, making it unintelligible outside.

  • Second perimeters or standoff distances: Additional barriers, like perimeter fences, prevent unauthorized access and eavesdropping.

Get It Right with Precision Security Consultants

SCIF requirements on Acoustics isn’t just about following a checklist—it’s about expert execution to ensure accreditation. Precision Security Consultants simplifies the path from concept to compliance, ensuring your SCIF or SAPF meets security and acoustic standards without costly rework. Contact us today to get it done right the first time.

 
 
 
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