· 9 min read
Ceiling Voids, Door Seals and Head Tracks: Where Acoustic Performance Is Lost
A technical guide to acoustic detailing in glass partitions: ceiling voids, head and base tracks, deflection heads, door seals, junctions and services.
Key takeaways
- A partition performs only as well as its weakest path.
- Ceiling voids are the most common flanking route in offices.
- Deflection heads need acoustic sealing without restricting movement.
- Door perimeters and thresholds need dedicated seals.
The weakest-path principle
Sound takes every available route. A small gap can undo much of the benefit of high-performance glass, because the gap transmits sound far more easily than the glass. That is why detailing matters so much on the acoustic glass partitions we install.
Ceiling voids
Where the partition stops at a suspended ceiling, sound passes into the void and down into the next room. Options include acoustic plenum barriers above the partition line, taking the partition up to the soffit, or using an acoustically rated ceiling. Barriers must be sealed around services.
Head and base tracks
Tracks should be sealed to the ceiling and floor with acoustic sealant or gaskets. Deflection heads, which allow the slab to move, need a sealing detail that stays airtight through that movement.
Door seals
Perimeter seals close the head and jambs; an automatic drop-down seal closes the threshold. Seals need adjustment at handover and periodic maintenance. See glass office doors.
Junctions and services
Junctions with mullions, columns and walls should be sealed with acoustic infill. Ducts, cable trays and sprinkler pipes passing over or through the partition line must be boxed or sealed.
Detailing checklist
- Ceiling void barrier or partition to soffit
- Sealed head and base tracks
- Acoustic deflection head detail
- Framed door with perimeter and drop-down seals
- Sealed junctions with building fabric
- Sealed services penetrations
Questions
Who should design the acoustic details?
On larger projects, an acoustic consultant. On smaller projects we detail to the system’s tested configuration.