How does laminated glass reduce noise?

Laminated glass cuts noise because of the plastic interlayer bonded between its two panes. Sound travels as vibration, and when it hits ordinary glass the whole pane vibrates and passes much of that energy straight through to the other side. In laminated glass the interlayer acts as a damping layer: it absorbs and dissipates the vibration as it tries to pass from the outer pane to the inner one, so less sound energy reaches the room. The result is a noticeably quieter pane than a single sheet of standard glass of the same thickness.

A few things make the difference bigger:

• Acoustic interlayers. Standard laminated glass already helps, but laminated glass made with a dedicated acoustic interlayer is tuned specifically to dampen sound and performs better again. This is what’s usually meant by “acoustic glass.”
• Mismatched pane thicknesses. Within a sealed unit, using two panes of different thickness widens the range of sound frequencies the glass can absorb — two identical panes tend to let the same frequencies through, whereas differing thicknesses close that gap.
• The cavity and the seal. In a double-glazed unit the air or gas gap between panes adds further sound resistance, and a well-sealed installation with no air paths around the frame matters just as much, because sound leaks through gaps as readily as air does.

Laminated glass also does two jobs at once: as well as reducing noise, the interlayer holds the glass together if it breaks, which is why laminated is also used as safety glass and for added security. So acoustic laminated glass can give you quiet, safety and security performance in a single unit, and it can be combined with low-E coatings so you don’t lose thermal efficiency. If noise is a concern on your project, mention it when you order and the SevenDay team will specify a suitable acoustic laminated build-up.