What is STC Rating?
An STC is the most common measurement used for sound reduction. An STC is a rating of how well a wall, floor, door, or window assembly diminishes airborne sound and prevents it from passing from one side to the other. In short, an STC roughly measures how much a barrier reduces sound. Higher values show that more sound is effectively isolated. An STC rating of 25 is roughly equivalent to normal speech not being heard through the assembly, whereas an STC rating of 50 is equivalent to loud speech not being heard. The STC scale is nonlinear and an increase of 10 on an STC rating scale translates to an approximate reduction of apparent loudness to half measure. This concept remains vital when multiple guests of different lifestyles occupy a tight footprint.
# 1 Verify STC Rating
An STC is the most common measurement used for sound reduction. An STC is a rating of how well a wall, floor, door, or window assembly diminishes airborne sound and prevents it from passing from one side to the other. In short, an STC roughly measures how much a barrier reduces sound. Higher values show that more sound is effectively isolated. An STC rating of 25 is roughly equivalent to normal speech not being heard through the assembly, whereas an STC rating of 50 is equivalent to loud speech not being heard. The STC scale is nonlinear and an increase of 10 on an STC rating scale translates to an approximate reduction of apparent loudness to half measure. This concept remains vital when multiple guests of different lifestyles occupy a tight footprint.
For most applications, the International Building Code (IBC) requires a minimum STC of 50 for floors and walls in commercial buildings. However, most hotel franchises require ratings above and beyond this to ensure guest comfort. For your immediate reference, the STC rating for a basic 2×4 walls with a single layer of ½” drywall on each side is typically around 33.
STC Rating by Brands
The chart below summarizes several flag’s STC varying requirements. Variations in STC values for walls and ceilings often reflect shifting standards according to the dates of construction. To assist you in your next project, consider the list below of minimum STC ratings by brand for three separate assemblies, including guestroom to guestroom walls, guestroom to corridor walls, and guestroom ceilings. These values remain applicable for mid-scale select, limited, and extended stay properties. Some full-service and luxury-scale properties may require more stringent requirements.
