Due to increased mass poured concrete and concrete blocks typically achieve higher stc values in the mid stc 40s to the mid stc 50s than equally thick framed walls.
Stc of concrete block wall.
Mate the stc for concrete ma sonry walls based on their weight.
The stc of a wall is determined by comparing sound transmission loss stl values at various frequencies to a standard contour.
In general a higher stc rating blocks more noise from transmitting through a partition.
Stc is highly dependant on the construction of the partition.
Determining sound transmission class stc for concrete masonry.
8 concrete block hollow core painted 2 coats 2 sides.
Installing insula tion within a wall or floor ceiling cavity will improve the stc rating by about 4 6 db which is clearly noticeable1.
Tek 13 1c sound transmission class ratings of concrete masonry walls contains a complete discussion on determining stc ratings applicable building code requirements as well as tabulated values for various 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.
Standard stud wall with one layer of 16mm 5 8 plasterboard.
Typical wall construction with 1 layer of 16mm 5 8 plasterboard on each side of 95x35mm 4 x 11 2 timber studs.
Estimated stc ratings for cmu walls the stc rating of a cmu wall can be estimated based on its weight using the following formula.
1 contains procedures for determining stc values of concrete masonry walls.
Stc 20 50 234w eqn.
8 concrete block hollow core no wall finish.
However the additional weight added complexity of construction and poor thermal insulation tend to limit masonry wall partitions as a viable sound isolation solution in many building construction projects.
The calculation in tms 0302 is based on a best fit relationship between concrete masonry wall weight and stc based on a wide range of test results.
Stc hollow with insulation 52 53 56 59 corefoam masonry foam insulationis an excellent product for improving thermal and acoustic properties of walls constructed with concrete masonry units cmu.
According to the standard stc can be determined by field or laboratory testing in ac cordance with standard test methods or by calculation.
Stc ratings for masonry cmu walls is based on weight of the block and whether the cells are filled or not and what material it is filled with.