A wood stud wall with regular 5/8” drywall and 3-1/2” of insulation has an STC of 46, with steel studs that will improve that to 49. Doubling the drywall on steel studs brings the STC to 58, plus it doubles the fire rating to 2 hours.
| Description | Estimated STC Rating |
|---|---|
| 2x4 studs, 5/8" gyp (2 layers total), Batt insulation | 56 - 59 |
| 2x4 studs,5/8" gyp (3 layers total), Batt insulation | 59 - 60 |
| 2x4 studs, 5/8" gyp (4 layers total), Batt insulation | 58 - 63 |
How to determine the STC rating of a wall?
What Changes a Wall’s STC Rating?
- Wall Material. The material and thickness of the actual wall have a huge impact on the STC rating. ...
- Vulnerable Areas. A wall might mostly be soundproof, but it just takes a weak point or two for the STC rating to go down.
- Frequency. Different sounds are blocked more effectively than others. ...
What is an acceptable STC rating?
STC window rating depends upon several factors – glass thickness, laminated glass, the airspace between panes, and how and what the frame is constructed of. A rating of 40 is the minimum for conversation privacy, and many building codes now require a rating of 50 to 55. A window with a rating of 40 should decrease the sound transmission by ...
What is the difference between STC and RW ratings?
The difference between STC and Rw is the range of frequencies that are tested in order to determine dB reduction and how to factually use or interpret the resulting numbers. STC covers the range from 125 Hz to 4000 based on ASTM E-90 and E413 test procedures. ASTM E-90. Rw covers the range from 100 Hz to 3150 Hz: it is an ISO rating and part of ...
Is a lower or higher STC rating better?
Is a lower or higher STC rating better? Higher STC ratings generally are better. This means that extremely low frequencies don't register on the STC rating scale, thus when a sound on one side of a wall is below 125Hz, the ability of the wall to block sound cannot be calculated.
What is the STC rating for drywall?
Common partition STCSTCPartition type27Single pane glass window (typical value) (dual-pane glass window range is 26–32) "STC Ratings".33Single layer of 1/2" drywall on each side, wood studs, no insulation (typical interior wall)39Single layer of 1/2" drywall on each side, wood studs, fiberglass insulation14 more rows
What is the STC of a 5'8 drywall?
between 30-34With two sheets total, of 5/8” drywall utilizing standard insulation we often see STC ratings ranging between 30-34.
Is an STC rating of 50 good?
A sound blocking level of STC 50 means that a listener in a quiet room would need to exert effort to hear raised speech levels in adjacent rooms, and the speech would not be understandable or disruptive.
What is the STC of a standard wall?
30 to 34Typical existing wall construction (the most common method is wood stud construction with insulation and 5/8” drywall on both sides) has an STC rating of 30 to 34.
Is STC 60 good?
An STC rating of 20 is considered very poor while a rating of 60 is considered excellent . For example, if you were in a room where a wall joining an adjacent room had an STC rating of 20 you would be able to hear someone speaking at a low volume through that wall.
How can I get STC rating of 60?
Summary: Increasing STC Ratings Use common rules of thumb, including moving to lighter gauge studs and spacing studs further apart. Then consider adding soundproof membranes and other soundproofing materials to improve your wall STC to 50, 55, or beyond.
What does STC 55 mean?
STC 55-65 – Most noises inaudible. Loud sources may be barely detected, and hard to define. Uses: Recording studios; “serious” cinema and music rooms. Examples: double door studio ”airlocks”; sealed + spaced double walls; very thick poured concrete walls. STC 65+ – Not found in 'normal' life or construction.
What does STC 48 mean?
Steel Stud WallOne has an STC 47 (4" Solid Concrete), the other an STC 48 (Steel Stud Wall). Note that in the low-frequency range - important for music, theaters, traffic, aircraft, and most other real-world noise sources - the lower STC wall is literally 30 decibels better, yet lower STC.
Is an STC of 37 good?
STC rating of 38-42 is considered good soundproofing for residential. STC rating of 50-65 is professional, commercial soundproofing for recording studios, etc.
Is drywall good for blocking sound?
While conventional drywall will help muffle sound, it won't completely block out noise. Most drywall has a solid core made of gypsum, a mineral made of calcium sulfate that is commonly used in building projects.
Does double drywall reduce sound?
Green glue is a material that isolates sound and reduces the energy transfer between the layers. Double drywall on the ceiling can help too, but will not be as noticed unless there is a room directly above the theater or you are worried about leakage outside.
Does thicker drywall help with sound?
More thickness means more mass and more mass means better soundproofing. The 5/8″ is also more durable sheetrock versus the 1/2″ option.
How do you calculate STC for walls?
Find the average transmission loss: Add up all the total frequencies you recorded, then divide that number by the total number of frequencies you tested. For example, if you recorded all 16 frequencies, divide your total by 16. The number you calculate is your STC rating.
Is STC 73 good?
IIC72/ STC 73 Rigid Core Flooring Underlayment is rated 4.9 out of 5 by 7. Rated 5 out of 5 by Alex from Good flooring underlayment Good rigid core flooring underlayment, only 1.5 mm thick. Rated 4 out of 5 by JJJ58 from The thickness is 1.5mm, not 2mm. Nothing fancy, but hopefully it does its job.
Which wall assembly has the best STC rating?
Drywall between double studs can dramatically reduce the STC rating of an assembly.Insulation will noticeably improve the STC rating of an assembly. ... Staggered or double stud walls are higher rated than single stud walls. ... Metal stud walls perform better than wood stud walls.More items...
What is the STC rating of Green Glue?
A high STC rating, suchs as 60, means less noise is traveling from room to room. Green Glue Noiseproofing products make high STC ratings achievable with minimal expense compared to other noiseproofing options. Green Glue Noiseproofing Compound is not assigned one particular STC rating on its own.
What is STC rating?
Almost always shortened to STC, it is the standard way to measure just how well certain materials are in regards to blocking sound. A lot of companies include STC rating numbers, so a person does not have to determine the rating themselves. However, it is still important to know how to determine the STC rating of a wall at home before ...
Why are walls higher in STC?
Thicker walls have more mass, and that leads to a higher STC rating. This is a pretty straightforward process, but it becomes trickier when walls are pretty much the same in thickness, but different material.
What affects STC rating?
The material and thickness of the actual wall have a huge impact on the STC rating. Ratings will differ quite a bit between walls made of concrete or drywall, and even between concrete and drywall options of different thicknesses.
How to improve STC rating?
Something like mass loaded vinyl, soundproofing panels, and more are all pretty cheap to purchase, and capable of full insulation without any professional help. Increasing air space in between two walls is another way to improve the STC rating.
When did STC ratings start?
STC ratings first popped up in the 1960s, as more and more people were looking to reduce sound transmission as much as possible between rooms at home, businesses, and more. This provided a uniform way to compare different types of materials as easy as possible. ( source)
Does STC rating matter?
This gives some varied answers for sure, which is what is used as part of an average to give an official STC rating. If only one or two types of frequencies are predominant in an area, the overall STC rating might not matter as much.
Is STC rating low?
In some cases, there might be limited options that actually work. In other cases, there is so little soundproofing done already that the STC rating is very low. That can be good news for people who want to take care of everything themselves because they can virtually start from scratch.
What is the STC rating of 5/8 drywall?
With two sheets total, of 5/8” drywall utilizing standard insulation we often see STC ratings ranging between 30-34. With two total sheets of ½” drywall (common for residential interior walls) we usually see an STC rating of around 33.
What is STC rating?
What is an STC Rating? STC, or rather “ sound transmission class” for those of you that paid attention in school, represents an integer rating of how effective a partition (say a building wall) attenuates airborne sounds.
How is STC measured?
STC ratings are measured using a uniquely designed scale where the higher the number is, the greater the ability of the measured structure or material to reduce sound transmission (i.e. better soundproofing qualities).
What is the STC rating for a multi-unit office?
Alternatively, STC ratings into the 50s and 60s or higher would be ideal for multi-unit living spaces and commercial business offices.
Why do we need to measure STC ratings?
Because perception of sound is unique to each individual and up to interpretation, STC ratings need to be measured in order to calculate noise reduction capabilities on measurable facts, not individual opinions.
When was STC rating first used?
Widely considered a standard in the United States, since 1961, STC ratings have been applied to both residential and commercial construction alike as a way to measure the soundproofing ability of the following to reduce sound transmission between rooms:
What is the best protocol to follow to make sure the testing is accurate, reliable and repeatable?
Testing in accordance with recognized standards is generally the best protocol to follow in order to make sure the testing is accurate, reliable and repeatable. Testing in this way involves the use of an amplified speaker that produces broadband noise in one room (referred to as the “source”).
What channel can improve the STC rating of an assembly?
4. Resilient channel can improve the STC rating of an assembly.
Does insulation improve STC rating?
1. Insulation will noticeably improve the STC rating of an assembly.
What is the STC rating of a wall?
The STC rating of walls has to do with multiple variables. Things like the thickness and air space within the wall can improve the rating greatly. For example, a standard interior wall, meaning two sheets of ½ inch drywall separated by wood studs and no insulation, provides an STC rating of 33, which provides almost no soundproofing.
What is the STC rating for paper thin walls?
That being said, anything below an STC rating of 40 might garner comments about paper thin walls. At these very low ratings, most things happening on the other side of the wall can be heard.
How to increase STC rating?
Filling that gap with STC rated insulation, like CFAB Cellulose-Based Acoustical & Thermal Panels will increase the STC rating even more. Adding treatments inside the room will help stop noise volumes inside the room from increasing too much, but making meaningful changes to your STC rating generally involves making some structural changes.
Why is STC rating important?
The STC rating is important when you are trying to reduce the amount of sound entering or leaving a room. The NRC rating is important when you are trying to reduce echo and improve the sound quality in a room.
What is a good STC rating?
A good STC rating is largely determined by the type of noise issue you are trying to solve, and the results you are trying to achieve. What works well for normal speech volume between two adjacent apartment rooms may fail miserably when you host garage band practice in your basement.
What does a class rating mean in audio?
Sound transmission class rating numbers give you a rough idea of how much sound is reduced in decibels (db). There is no exact correlation from STC rating to db, however, since materials block sounds of varying frequencies differently.
What is the STC for multifamily?
The International Building Code requires an STC of 50 for multi family construction, which is the point at which noise is reduced to a point that people generally feel like their homes are adequately insulated from noise.
What are STCs and Why are They Important?
When particles vibrate, this creates a wave that your brain recognizes as sound.
Comparing STC Ratings to Real Performance
STC ratings carried out in a laboratory cannot take all other noise factors into account in real-life situations
How to Determine the STC Rating of Walls, Drywall, and Windows
The Uniform Building Code (UBC) classes apartments in Group-R, which require an STC rating of 50 or an FSTC rating of 45.
What affects STC Ratings for Walls?
Numerous factors can affect STC ratings, which have to be considered as a whole, to determine the STC rating of a wall.
Conclusion
When considering moving homes, it is highly advisable to ask your contractor or local municipality for your STC ratings for walls.
