Wall Sections
6 wall assemblies with layer-by-layer construction details. All STC ratings and layer stacks from SSOT.
Wall 1: North concrete wall
| STC Rating | 65 |
| Field STC Est. | 58–62 |
| Treatment Depth | 10 cm |
| Total Layers | 6 |
Concrete mass + resilient clips; field loss from penetrations and edge sealing
Wall 2: West diagonal — existing gypsum + NEW independent inner leaf (PW-02)
| STC Rating | ~60 (class) |
| Field STC Est. | 55–60 |
| New Build-up | ~13 cm |
| Total Layers | 4 |
The existing west diagonal is a GYPSUM stud wall (S3-SITE-TRUTH §2, photo IMG_1291) — the old “RSIC clips on concrete” W2 design is VOID. A free-standing inner stud leaf, never tied to the existing wall, is the only correct isolation here. Any fixing into the existing leaf collapses the estimate.
Wall 3: East — existing gypsum leaf to B313 server room + NEW decoupled stud leaf (PW-04)
| STC Rating | 62 |
| Field STC Est. | 55–59 |
| Treatment Depth | 16 cm |
| Total Layers | 4 |
The existing east leaf is GYPSUM with a ~100mm air gap to the B313 block wall behind (S3-SITE-TRUTH §2). B313 is a SERVER ROOM running 24/7 — the air gap is the decoupler: keep it UNFILLED and never bridge it. Server-side vibration may reduce performance.
Wall 4: South — existing gypsum partition lined/rebuilt to STC 50 (PW-03)
| STC Rating | 50 |
| Field STC Est. | 44–48 |
| Treatment Depth | 15 cm |
| Total Layers | 5 |
Green Glue CLD on both faces is required [AC]; D1 exterior door is still the weakest link in this wall. The south wall is a GYPSUM interior partition (S3-SITE-TRUTH §2) — D1 + D5 are NEW FRAMED OPENINGS on structural steel subframes per the IAC doorset schedule (BOQ D-07): NO concrete cutting, NO lintels, stud framing only.
Wall 5: Buffer spine — NEW BUILD (W-07)
| STC Rating | 55 |
| Field STC Est. | 49–53 |
| Treatment Depth | 15 cm |
| Total Layers | 5 |
NEW BUILD (BOQ W-07) — the site is an empty shell; no spine exists, nothing to demolish. Double-leaf x=213.6→228.6, full depth y=0→431, independent frames, head sealed to slab, STC 55 class. Green Glue CLD improves mid-frequency; duct penetrations must be fully sealed
Wall 6: VO/Control partition
| STC Rating | 53 |
| Field STC Est. | 47–51 |
| Treatment Depth | 12 cm |
| Total Layers | 3 |
Staggered-stud partition with no Green Glue; observation window remains the weakest element and composite STC depends on seal integrity.