Sound Transmission Class Ratings For Concrete Masonry Walls

Stc sound transmission class rating w wall weight based on the average density of the masonry units the weight of mortar grout loose fill materials and the weight contributed by surface treatments.

Sound transmission class ratings for concrete masonry walls. Weather and sound 3 stc ratings for wall floor and window materials and assemblies 3 appendix a stc ratings a 1 walls a 1 exterior a 1 interior a 9 wooden studs a 9 metal studs a 14 floors a 16 wood a 16 concrete a 21 windows a 24 doors a 27 exterior a 27 interior a 29 appendix b references b 1. Sound transmission class stc for lightweight concrete masonry walls masonry wall thickness 4 inch 6 inch 8 inch 12 inch plain 40 44 45 painted 41 45 46 50 wall board 47 49 56 plastered 50 50 51 cores filled with insulation 51 composites cavity grouted 8 4 block plus 4 concrete brick plain 51 1 2 plastered on block. In general a higher stc rating blocks more noise from transmitting through a partition. 2 provides stc ratings for com mon wall assemblies.

Concrete masonry walls are. Stc is highly dependant on the construction of the partition. Sound transmission class stc provides an estimate. Determining sound transmission class stc for concrete masonry sound transmission class stc provides an estimate of the acoustic performance of a wall in certain common airborne sound insulation applications.

In general the heavier a concrete masonry wall is the more effectively it will block sound transmission. The national concrete mason ry association ncma provides t h e f o l l o w i n g e q u a t i o n t o e s t i mate the stc for concrete ma sonry walls based on their weight. Thus heavier walls have a higher rating. 1 contains procedures for determining stc values of concrete masonry walls.

The sound transmission class stc is a single number rating of a material s or an assembly s ability to resist airborne sound transfer at the frequencies 125 4000 hz. To achieve performance compa rable to a masonry wall a stud. Sound transmission class ratings for concrete masonry walls introduction. Determining sound transmission ratings for masonry walls tms 0302 ref.

According to the standard stc can be determined by field or laboratory testing in ac cordance with standard test methods or by calculation. Unwanted noise can be a major distraction whether at school work or home. The calculation in tms 0302 is based on a best fit relationship between concrete masonry wall weight and stc based on. Stc ratings for concrete masonry walls are determined using standard method for determining the sound transmission class rating for masonry walls tms 0302 ref.