If you have an stc 45 wall this does not mean the wall stops 45 db of sound.
Stc drywall 2 sheets.
Tips for drywall sheets always choose thick sheets 1 2 or 5 8 if you re installing drywall on your ceiling.
You cannot add stc ratings.
With two total sheets of drywall common for residential interior walls we usually see an stc rating of around 33.
You can find this type of drywall at your local home depot or by clicking this link.
You might get something around stc 35.
If you have an stc 33 wall and decide to add another sheet of drywall with an stc of 20 you do not get a finished wall with an stc of 53.
Thinner drywall sheets such as 1 4 or 3 8 will sag in between rafters over time.
It s important to know each side of the drywall sheet.
They are logarithmic values and cannot simply be added.
The sheets are available in thicknesses of 1 2 5 8 and 1 3 8 with dimensions of 4 x8 9 or 10 feet.
Combined the sheet will reduce the transmission of sound in or out of a room by between 15 and 20 stc points when compared to standard drywall sheets.
The side that s gray or ivory should face the room.