Floor-Ceiling and Volume-Ceiling Assemblies

GOALS

Reduce ambient, flanking, and impact noise between two levels/units with a shared floor/ceiling; reduce reflective noise from inside rooms with volume ceilings.

BASICS
  • Refer to “Basics” in “First-Floor Platform Assemblies,” page 390.
  • Specify insulated/sealed recessed light fixture housings and foam-seal around openings at the drywall for all ceiling-hung light fixtures.
  • Use flexible/woven joint tape at all drywall joints to bridge panels and reduce the potential for wall cracks.
  • Install an acoustical layer (foam mat, sheet membrane, subfloor panels with integral metal and/or viscoelastic polymer layers) on the floor side of the assembly to reduce impact noise transmission. Note: Foam mat is sandwiched between two layers of subflooring; sheet membrane is installed between floor frame members and a single subfloor panel.
    • UPGRADES AND OPTIONS
  • Insulate floor cavities with full-depth fiberglass batt insulation; cut and/or form around penetrations and light fixtures.
  • Install an acoustical layer (foam mat, sheet membrane, drywall panels with integral metal and/or viscoelastic polymer layers) on the ceiling side of the assembly to reduce impact noise transmission.
  • On flat ceilings, install acoustical panels in a dropped grid frame to absorb reflective sound and block impact sound from above.
  • On volume ceilings, install a fabric membrane over an acoustical panel to absorb reflective sound.
  • For the roof, consider SIPs, which usually permit longer/open spans on the interior, are self-insulated, and have substrates ready to finish upon installation.

    • CODES COMING?

    Sound transmission standards for all residential buildings are already in the building code as well as guidelines set and enforced by HUD, the EPA, and other agencies. But even heightened awareness (and litigation) regarding sound performance will not likely push more regulations on builders to reduce noise, especially for single-family detached homes. “Just raising the STC rating won't do it,” says the NAHB Research Center's Nader El-Hajj, noting not just the likelihood of field failures but also the inability to enforce higher standards beyond a plan check. Owens Corning's Portia Ash agrees: “It'll have to be consumer-driven, because most of [the noise] we're talking about is generated by the owner, so it's subjective.” But she does see the potential for stronger noise-related codes for homes near airports and highways. Even then, says Quiet Solution's Marc Porat, single-family builders herded onto such parcels by sprawl-deterring policies face a marketing nightmare: “Developments on the side of a highway are not sellable,” he says. “People walk in [to a house], hear the persistent rumble of the highway, and walk out.”