Doors, windows and glass partitions play a major role in improving aesthetics. But what about acoustics? Does thicker glass reduce noise? Let’s find out.

The straightforward answer to the question is “YES”. Thicker glass reduces noise. Does it mean we should use 1-inch (25.4 mm) thick glass? – NO.

Double Glazed, Triple Glazed and Laminated Glass:

The best solution is to use double-glazed or triple glazed units. You can also use a laminated glass.

The double-glazed unit is made up of two thin glasses with a gap in between. For example, a structure of two 3 mm (1/8”) glass with 6 mm (1/4”) air gap in between.

Triple glazed will have three plies (lite) of glass in different size (thickness) combinations.

Laminated glass is a two glass pieces stick together with PVB in between. PVB stands for Polyvinyl Butyral.

So, any glazing element in your house or office will be one of the following:

Single Lite (Monolithic)

Double glazed

Triple glazed

Laminated

Noise Reduction and Tests:

There are two measures to verify how much your glass or glazing system like windows can resist noise. Sound transmission class (STC) and Outdoor/Indoor Transmission Class (OITC). They are measured in decibels (dB). These two methods are used in rating the glass or glazing systems. The higher the STC (or OITC), the higher the sound attenuation properties.

STC rating is used for interior glass elements like glass partitions. While, OITC is used for exterior glazing like exterior windows.

Below are some examples of how increasing in the glass thickness will reduce the noise:

(Keep in mind higher STC or OITC meaning higher the sound proofing)

Monolithic Glass (Single glass/ lite):

1/8” Glass: STC 30, OITC 25

1/4” Glass: STC 31, OITC 29

3/8” Glass: STC 34, OITC 32

1/2” Glass: STC 36, OITC 33

Double glazed:

1/8” Glass + 3/8” Air gap + 1/8” Glass: STC 31, OITC 26

1/4” Glass + 1/2” Air gap + 1/4” Glass: STC 35, OITC 30

3/8” Glass + 1/2” Air gap + 3/8” Glass: STC 37, OITC 32

1/4” Glass + 1” Air gap + 1/4” Glass: STC 37, OITC 30

Triple glazed:

1/4” Glass + 1/2” Air gap + 1/4” Glass + 1/2” Air gap + 1/4” Glass: STC 39, OITC 31

 Laminated:

Two 1/8” glass laminated:  STC 35, OITC 31

Two 1/4” glass laminated:  STC 38, OITC 34

Two 1/8” glass laminated (with double thick PVB in between): STC 39, OITC 34

So, it is not just a glass and frame. Manufacturers design the glazing, windows and doors based on thermal and sound insulation needs. Hope the above information was useful to understand the glass thickness vs. sound attenuation.