How sound transmission class (STC) tests for wall joints are conducted


When Trim-Tex says all their code compliance solutions for wall joints produce the equivalent or greater soundproofing capabilities as acoustical caulk, with none of its drawbacks, how do they know that? Recently, a employees of engineers at North Orbit Acoustic Laboratories in St. Paul, Minn., pitted two of Trim-Tex’s fire rated drywall gear, Hotrod XL and Fire Bead, head-to-head in direction of acoustical sealant inside the closing soundproofing check out. 

For just a few years, the widespread method to seal the gaps around drywall to dampen sound was with acoustical caulk. But as anyone who’s labored with any such sealant is conscious of, it’s tough to apply evenly, and over time, it hardens and shrinks back. An environment friendly soundproofing decision desires to remain versatile to remain environment friendly.

The NOAL employees performs acoustical tests by establishing two virtually related rooms outfitted with cutting-edge audio instruments, with a niche between the two areas. In that opening, a field-accurate wall assembly was constructed using metallic studs, R-13 batt insulation and ⅝” Type X drywall. Loud noises are blasted from one facet of the testing facility, and the amount of sound that passes by to the alternative facet is then measured as a Sound Transmission Class (STC) price.

For the first check out, sound sealant was utilized on all 4 sides of the wall, filling the half-inch gaps between the drywall and the check out opening. Sealant like this takes weeks to completely therapy, so on this check out, it was left in a moist state, which could give it the very best STC price. After the sealant hardens, its sound-dampening capability would decline.

The sound check out commenced, with a outcomes of fifty STC, the accepted customary for most developing codes.

To put collectively for the second check out, the sealant inside the edges and prime of the wall assembly was painstakingly eradicated. The employees then put in Trim-Tex’s Hotrod XL alongside the head-of-wall joint. Hotrod XL’s compressible foam center is designed to sort a perfect seal upon arrange, providing ¾” of structural movement and staying utterly versatile. Meanwhile, Fire Bead, with its versatile apex gasket, is perfect for finishing vertical gaps and defending them from the passage of fireside, smoke and, positive, sound; this decision was used alongside the perimeters of the check out opening. The two utterly completely different fire rated vinyl beads had been stapled into place every two to 4 inches, and accomplished with five-minute scorching mud to get it ready in time for their check out. 

And as quickly as all was said and executed, the employees at NOAL had a consequence: a 51 STC, a full degree larger than acoustical sealant. A single degree couldn’t indicate the whole thing in every self-discipline, nonetheless for acoustical testing, it’s a major assertion. 

With third-party sound testing achieved, it proved that Trim-Tex’s code compliance choices current the upper STC values as acoustical caulk. Plus, with these fire rated drywall gear, you moreover get most likely probably the most superior fire stopping proficiency chances are you’ll get, ensuing from intumescent tape that expands to 30 situations its dimension when uncovered to intense heat. And you get far longer-lasting flexibility for developing movement, stopping cracks in your finish and completely different, further vital types of damage. And you’re getting a cleaner, faster, further foolproof arrange. And you’re getting a further aesthetically crisp finish in your drywall. And you gained’t should tear all of it out and do it as soon as extra in 5 years; you have bought obtained an environment friendly fire-resistant, soundproof setup that will closing the lifetime of your wall. When one gives up the true price they are receiving with Trim-Tex’s groundbreaking code compliance choices, there’s truly no comparability the least bit.

Learn more about these sound tests and their results, including photos, video and technical specs, here.