Sound Transmission Class Rating
Wall partitions tested at NVLAP certified Western Electro – Acoustic Laboratory in accordance with provisions and requirements of ASTM E 90-04 – Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions provided several ratings.
Results show use of BlazeFrame products at the head of wall in different assemblies with 1/2” “open joints” (no caulk) provide Sound Transmission Class ratings (in accordance with ASTM E 413-04) in the same range as partitions listed in the Gypsum Association GA-600-03 design manual using caulk in gaps.
- Chase Wall Assembly – STC 62 – Report No. TL08-572
- Single Wall Assembly – STC 52 – Report No. TL08-574
Affixed intumescent materials enable compression of fire stop materials against overhead structures providing a seal between overhead and BlazeFrame profiles. The 2 mm thickness of affixed fire stop materials being slightly thicker than wafer head fasteners (used to positively attach studs) provides a seal between “framing” materials and wall sheathing materials.
Cured and affixed intumescent located “behind” dynamic deflection gaps incorporated in BlazeFrame composite profiles have shown no fatigue to joint system materials during expansion and contraction of joint at seismic levels of movement. No fatigue to system for “life of system” provides a joint seal against air/airborne sound transmission that will not degrade over time. STC ratings in dynamic joints (under current provisions and requirements of sound tests) may be conducted while “caulk seal” has not cured nor experienced any dynamic cyclical movement (head of wall joint). Ratings using caulks to seal joints may not represent actual long term conditions of these “wet applied” mastics.
Possible degradation of joint seals during lifetime of “wet-applied” mastic caulk or sprays due to shrinking/cracking during curing, adhesive failure to overhead/wall sheathing, cohesive failure of caulk material, or dislodging due to cyclical movement is eliminated with use of BlazeFrame profile designs.
*Reports on file available upon request
