Acoustic-Rated Assembly Guide
How to review STC-rated walls, IIC-rated floors, penetrations, doors, ceilings, flanking paths, and finish details for acoustic performance.
Acoustic ratings are only as good as the installed assembly. A wall with a high STC rating can fail when the door, glazing, outlet boxes, head-of-wall joint, above-ceiling return path, or unsealed penetration bypasses the rated assembly.
The drawing review should identify both the rated assembly and the paths that can flank around it.
What to Compare
Acoustic performance is shown across architectural wall types, door schedules, finish plans, MEP penetrations, ceiling details, and specifications. The most important review question is whether the rating is continuous in the built condition.
- STC or IIC rating shown in the wall, floor, or ceiling assembly.
- Door, frame, glazing, and seal ratings.
- Back-to-back electrical boxes and other penetrations.
- Duct, grille, transfer air, and plenum flanking paths.
- Head-of-wall and floor line sealant details.
- Finish details that interrupt resilient channels or isolation systems.
How Helonic Helps
Helonic helps identify drawing conditions where acoustic assemblies are interrupted by other trades. That gives the design and construction team time to clarify details before the wall is closed.
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