Understanding Soundproofing Concepts

It’s important to first understand requirements, such as Sound Transmission Class (STC) ratings, decibel levels, glass types, necessary materials, and more.

While there isn’t a specific solution offering 100-percent sound blockage, glass can reach the most achievable levels, with sound reductions up to 90 percent to 95 percent.

From STC ratings of 25, whereby normal speech can still be heard, to higher barriers ranging from 45 to 55, all solutions must adhere to the five principles of soundproofing.

These include:

• Mass: This ensures noise is more difficult to penetrate. The thicker the glass, the more challenging. 
• Mechanical Isolation: Built on separation, this requires sound moving through the air. When less materials move, sound diminishes faster.  
• Absorption: As this strengthens, more sound is eliminated and weakened across the surface.
• Resonance Dampening: Certain materials reduce sound levels by transforming mechanical energy into another form, such as heat. 
• Conduction: Sound decreases as it travels. 

Is Glass Good for Soundproofing?

​​Unlike other materials, glass provides a highly effective barrier for soundproofing, while upholding interior acoustics, transparency, and light. Its nonporous surface also ensures extraneous noise and other sounds don’t inadvertently leak through.

Glass facilitates some of the best soundproofing and acoustics levels through additional capabilities, such as double glazing, lamination, and others. However, if not executed properly by an experienced fabricator such as Dillmeier Glass Company, you could experience less-than-stellar results.

What Glass Thickness Is Best for Soundproofing?

With standard glass thickness levels ranging from 1/8 inch to 1 inch, the thicker the glass, the better the soundproofing. As aforementioned, to determine noise reduction levels, you must first examine STC ratings. 

Decibel value (dB) levels and how much noise your application can withstand are also things to consider. For higher noise levels, it’s best to implement laminated or double-paned glass for extra protection. For areas requiring less of a barrier, standard monolithic or single-pane glass are cost effective and work for most interior applications. 

Consult the chart below regarding specific thickness levels with corresponding STC ratings: 

What Are STC Ratings & Requirements?

An STC label characterizes how partitions and walls effectively block sound and reduce noise. Ratings are determined by broadcasting a specific auditory tone near the material, and measuring the dB on both sides. The higher the STC value, the better its insulation.

What Type of STC-Rated Glass is Required for My Project?

One of the first steps is determining STC-rated glass type, sound location, room type and acoustics, dB levels, and intended usage. Note glass sound reduction properties can vary due to material wavelengths. 

Keep in mind STC rankings are calculated using a formula that cannot be combined. For example, a single 1/4-inch piece of glass is 31 STC, but two 1/4-inch pieces next to each other equal 36, rather than 62 STC.  

Additional options include upgraded, separately framed glass panes known as lites. While these offer another alternative, they cost more and aren’t effective unless other areas of the room are tightly sealed.

What STC Ratings Are Best for Glass?

It’s prudent to decide required noise cancellation levels prior to purchasing any building materials, since different projects may demand specific requirements. 

Standard construction practices leave gaps, enabling noise to bypass even the most insulated walls. Soundwaves follow the path of least resistance and can travel through HVAC vents, up through ceilings and over walls, and even through electrical outlets. 

Noise movement through even the smallest cracks is called acoustic flanking, whereby glass walls constructed from 50 STC-rated materials can drop into the mid-30s. There are several options and upgrades you can implement to eliminate this noise, including adding drywall, filling gaps with acoustic sealant, and upgrading doors. You can also use a special ambient noise system known as sound masking. When broadcast at a specific frequency, this blocks noise throughout an office.

How to Choose the Best Type of Soundproof Glass

There are several strategies you can employ when choosing glass materials for effective soundproofing. Note STC panes vary by situation and use case.

Monolithic Glass

Created during the float glass manufacturing process, this single lite can be fabricated for a wide range of purposes and feature decorative enhancements. With a typical STC of 31 for 1/4-inch glass, up to 36 for thicker pieces, monolithic glass is the most basic of glass construction. 

Standard Glass

Standard walls in most homes are 33 STC, while studio-level soundproofing requires a rating of at least 45. With this in mind, a mid-30s score might seem low, but it’s suitable for office spaces without all-glass construction.

Laminated Glass

PolyVinyl Butyral (PVB) or Ethylene Vinyl Acetate (EVA) adhesives harden to sandwich two lites together, even if cracking occurs. PVB and EVA are solid insulators, with some laminated panes’ STC ratings reaching as high as 40 or more. The exact ranking depends on the glass and its adhesive thickness. Consider special acoustic interlayers to block higher noise levels if your budget permits. 

Double-Glazed Glass

Double-glazed, or double-pane glass features two lites in a frame with a layer of air between them. The gap between lites also provides acoustic insulation, to improve STC ratings. Heat efficiency usually requires a maximum gap of 16 millimeters, but a larger space is always better for soundproofing. 

Double-glazed glass can also achieve an STC rating of up to 40. Costing more than other materials, this is used mainly for exterior applications.

Laminated & Double-Glazed Glass

Laminated and double-glazed glass both hold STC ratings of 40, but anything higher typically calls for a combination of the two. Maximum noise insulation is achieved by laminating one or more lites in a double-pane piece.

Most glass advertised as soundproof consists of this combination for maximum noise cancellation, with STCs of 45 to 50, or higher. This typically isn’t necessary unless your application requires the highest soundproofing levels, such as a professional recording studio.

Single-Pane Glass

To achieve quieter office areas, ensure all gaps are sealed during construction, and install high-quality doors and drywall. With these improvements, single-pane glass is best for most interior applications. You can also add lamination to increase STC ratings, and therefore soundproofing.

Interior Soundproofing Best Practices & Tips

Keep the following in mind when considering soundproofing and acoustics:

• What is the current space layout?
• What technologies are used daily?
• How many people will be regularly utilizing the space?
• Is the space used for frequent meetings and conferences?
• Do you often host outside visitors, guests, and groups?
• Do certain employees require a quiet working space with minimal interruptions?
• Is your goal an open, collaborative atmosphere that still maintains productivity?
• Can the space support acoustic panels?
• Do you already have walls, partitions or dividers in place? If so, what types of materials do they comprise? 

Choosing the Best Soundproofing Levels

It’s best to work with an experienced fabricator such as Dillmeier Glass Company for guidance on soundproofing levels, STC ratings, and glass types.

Contact us to learn more about glass fabrication solutions for your interior soundproofing and acoustics needs.