SSOT v3.7 · Project Reference · Acoustic Design Basis
Material Substitution Guide — Damascus Local
Local procurement reference for specified acoustic products and acceptable substitutions. Any performance-affecting change requires written acoustic consultant approval before order release.
Scope
Materials + hardware
Market
Damascus local supply
Approval
Written consultant review
Import Items
GG + MLV + drop seals
Substitution Table
Performance First| Specified | Spec | Damascus substitute | Performance delta | Adjustment |
|---|---|---|---|---|
| Rockwool RWA45 100 mm | NRC 0.95, 45 kg/m³ | Isover IBR 40 or local mineral wool ≥ 40 kg/m³ | 0 to -3 dB if density is lower | Add 25 mm thickness if density < 40 kg/m³ |
| Rockwool ProRox SL 930 | NRC 0.90 ceiling | Mineral wool tile with NRC ≥ 0.80 | RT60 may increase 10–15% | Add 1–2 extra wall panels if NRC is lower |
| Sylomer SR28 | 28 kN/m², fn 8–12 Hz | Getzner Sylodyn NE or Farrat M28 | Equivalent if load spec is matched | Verify load rating against floor dead load before use |
| Tremco ACR sealant | Acoustic Class A | Low-modulus polyurethane acoustic sealant | Equivalent if Shore A < 20 | Perform adhesion test before full application |
| Tremco Fyre-Sil | 2 hr fire rated + acoustic | Hilti FS-ONE or 3M CP 25WB+ | Equivalent fire rating | Local fire inspector approval required |
| Green Glue compound | Constrained layer damping | No substitute exists | Cannot be substituted | MUST IMPORT — order 90 days before wall works |
| RSIC-1 clips | Decoupling resilient clips | Kinetics RIM or Mason Industries | 0 to -2 dB STC | Verify spacing per manufacturer spec |
| Rockfon Sonar E | NRC 0.90, Class A fire | Armstrong Ultima+ or Ecophon Solo NRC ≥ 0.90 | Equivalent if NRC matches | Same installation method |
| Pemko 411 drop seal | Automatic acoustic threshold | No local substitute known. Import or Athmer 1-731 | N/A | Order with doors |
| Mass Loaded Vinyl 6 mm | STC +5 dB contribution | No substitute exists | Cannot be substituted | MUST IMPORT — order 60 days before door works |
Must Import Items
Procurement Risk
Green Glue, MLV, and drop seals must be imported. No Damascus substitute provides equivalent performance. Order lead time: 45–90 days. All substitutions require written acoustic consultant approval.
Green Glue
Critical to W3, W4, W5, and W7 performance. Missing or substituting it reduces damping and risks STC shortfall.
Mass Loaded Vinyl
Needed in the door leaves to reach the stated door ratings. Do not replace with thin rubber, felt, or lead sheet improvisations.
Automatic Drop Seals
Acoustic thresholds require tested compression and reliable actuation. Generic door sweeps are not acceptable replacements.