Verco Steel Deck Sound Guide
Searching for a quiet space?
Verco can help you with the sound of silence.
Noise Reduction Coefficient (NRC) is the average of how much sound a assembly can absorb. The higher the NRC value of any assembly the better the product can act in soaking up sounds.
Sound Transmission Class (STC) is the assembly’s ability to block sound from traveling through the floor system as a whole i.e. to stop airborne noise for transferring from place to place and the IIC is the assembly’s ability to absorb impact sound i.e. footsteps on the floor and prevent it from being heard in another space. The higher the rating the less noise is transmitted.
What’s the bottom- line difference between the NRC and STC/IIC?
NRC – helps absorbs sounds in a room and helps reduce echo’s and ambient noise. One area or room at a time
STC/IIC – helps prevent noise from going into other rooms or areas of a building.
Dovetail Deck Sound Transmission Class
When used with a typical assembly, our dovetail deck sound transmission ratings (STC) and sound impact ratings (IIC) give you design freedom like never before and provides superior sound performance – boasting a variety of floor assemblies and finishes that provide STC and IIC over 50. Whether it’s engineered wood, ceramic tile or anything in between, our dovetail deck superior sound ratings give you the opportunity to create something that meets your customers’ needs and matches your creative vision.
At this time Verco does not offer tested STC/IIC ratings for our regular deck products. We do offer other options that can assist the designer of record with designing STC/IIC assemblies with regular deck.
Noise Reduction Coefficient
Verco’s 1½” and 3” deep fluted and cellular roof decks are available as acoustical decks. When used in a typical assembly, acoustical deck can provide sound attenuation/absorption within buildings where the deck is exposed to the interior. Verco offers acoustical assemblies of fully perforated versions of our 1½” and 3″ roof decks, designated as FP-11.
Standard Acoustical Roof Deck: The performance of 1½” and 3” acoustical decks is affected by the type of insulation placed above the deck. Acoustical performance data for fluted decks is shown with the historically used rigid fiberglass insulation board, polyisocyanurate insulation (poly-iso) board, and with roof board.
Cellular Acoustical Deck: Verco’s cellular decks are available in an acoustical version also. For cellular deck insulation batts are factory installed between the top fluted section and the flat perforated bottom plate. With cellular deck the choice of insulation placed above the deck has minimal impact on the acoustical performance of cellular deck, so only poly-iso is used in those assemblies for testing for roof deck. Cellular composite deck NRC values are the same as cellular roof deck.
The acoustical insulation batts used in fluted or cellular acoustical decks are available encapsulated (wrapped) as a special order. Optional spacers may be installed in cellular acoustical decks between the flat bottom plate and the insulation batts.
Acoustical Deck Fire Ratings: All Roof deck acoustical uses are limited to non-fire-rated assemblies. Some limited composite deck assemblies using cellular decks and concrete topping have UL assemblies. Please see Verco’s UL Floor Data Sheet for further information.