Sound Transmission Control

Architecture begins where engineering ends - Walter Gropius.

Peace & Quiet

Sound reduction is essential to maintaining peace of mind in the modern world. More than ever we are barraged by a background din of unwanted noise. It is particularly hard to concentrate when conversation or music from one space is heard in the adjoining space. This is often the case in open-plan offices but, as more people are now working from home, it’s a growing problem in the home office. Distracting noise reduces efficiency and increases stress. Acoustic privacy is critical not only in boardrooms, consulting rooms, and health care settings but in residential spaces as well.

Technology of Sound Insulation

Modern designers are turning to better technology to address the challenges of sound transmission. This includes improved wall and floor construction, as well as advanced technical improvements in glass construction for windows, doors and partitions. Which is why all EliteSteel interior doors and windows include “Wave Disrupting” sound technology that reduces sound transmission by up to 50% over your typical dual pane windows. We achieve STC (sound transmission control) ratings in the low 40’s by utilizing these 4 proprietary processes:

We utilize slightly different thicknesses of glass, so sound hitting one pane is transmitted at a frequency that does not resonate with the second pane.
We laminate two pieces of glass with VBA clear polymer bonding, creating an extra thick sound reducing glass. A third layer of glass with a gas fill can increase the sound reduction even further. This additional step can bring ratings into the high 40’s, barring other architectural factors.
Our thermal break system works to dampen sounds passing through the frame.
Our heavy duty four stage seals works to prevent ‘acoustic flanking’, or sound passing around the slab or sash.

*Depending on your requirement for acoustic privacy, we are happy to work with your architect or builder to achieve the desired results. Multiple factors need to be evaluated to get the highest degree of sound reduction, including construction of floors and walls.

About STC

STC or ‘Sound Transmission Class’ is a numerical method of rating how well a building element reduces sound transmission. The STC provides a standardized way to compare building materials, as well as products, such as doors and windows. A higher number indicates more effective sound insulation than a lower number. However, the STC rating uses a logarithmic scale like the ‘Richter Scale’ for earthquakes. An increase from 28 to 38 means that 90% of existing sound has been blocked. A change from 28 to 43 represents over 95% sound reduction! Small increases in the numerical rating translates into significant reduction of sound transmission. The increase from 38 to 43 mentioned above doesn’t sound like much (90% versus 95+% in reductions) – but going from 90% to 95% means that 60% of the remaining noise was removed; every single number therefore represents a large amount of noise!

Technical solutions for sound reduction depend on the source and type of noise and the path of acoustic transmission. The smallest structural gap can cause a disproportionate reduction in sound proofing. A 0.1% opening will reduce effective sound control from 40 dB to 30 dB, which is typical of walls where the caulking has not been effectively applied. Partitions that are inadequately sealed or contain back-to-back electrical boxes, untreated recessed lighting or unsealed pipes also offer significant flanking paths for sound leakage.

A major source of sound transmission can be the door itself. Even if the door is rated at 40 STC, if the installation isn’t done correctly, transfer of sound through clearances and gaps around the door can cause significant loss of sound control. EliteSteel doors and windows are highly rated for STC but to achieve the best results, a holistic approach to all aspects of the building structure must be considered. For this reason, the STC of a door is not sufficient unto itself in providing maximum sound reduction. For commercial or sound studio level sound reduction, we advise consulting with an acoustical engineer.

To give some examples for comparison: a standard wall in most homes has an STC rating of 33, while studio-level soundproofing requires a rating of at least 45. Most rooms in a luxury residential home should have STC ratings of 38-42

	STC	Performance	Description
	50-60	Excellent	Loud sounds heard faintly or not at all
EliteSteel with Extra STC	40-50	Very Good	Loud speech heard faintly
EliteSteel Doors & Partitions	35-40	Good	Loud speech heard but hardly intelligible
Regular Sheet Rock Wall	30-35	Fair	Loud speech understood fairly well
	25-30	Poor	Normal speech understood easily and distinctly
Typical Hollow Core Door	20-25	Very Poor	Low speech audible