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 |
What is the STC rating of drywall with studs?
If the drywall is constructed on hollow wood studs, the STC rating will be about 33dB. Which wall has the highest STC rating? The commercial product QuietRock has an STC rating of 56 when installed as a single stud wall
How to improve the STC rating of a wall assembly?
Staggered or double stud walls are higher rated than single stud walls. 3. Metal stud walls perform better than wood stud walls. 4. Resilient channel can improve the STC rating of an assembly. 5. Adding additional layers of drywall can improve the STC rating of an assembly. 6.
What is the STC of a 5/8 stud without insulation?
A few examples: 1 5/8″ metal studs, 5/8″ drywall (2 layers total), No insulation = STC of 38-40 2 2×4 stud, 5/8″ drywall (2 layers total) Plus Batt insulation = STC of 34-39 3 5/8″ metal studs, 5/8″ drywall (2 layers total) Plus Batt insulation = STC of 43-44
How do I know if my wall is STC 35?
If your wall graph is closest to a standard STC 35 curve, your wall is said to have an STC rating of 35. Adding Green Glue to boths side of a wall.
What is the STC rating of 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 rating of 5/8 gypsum board?
about 38–40The STC rating figure represents approximately the decibel reduction in noise that the assembly can provide. For an interior wall that is made of 3 5/8″ metal studs with one layer of 5/8″ gypsum board on both sides, the STC rating is about 38–40.
How do you get STC 50 walls?
Add Soundproofing Membranes: If you need to achieve an STC of 50 or higher, consider using a soundproofing membrane. These products offer decoupling by separating the drywall from studs, and also significant mass increases.
What does an STC rating of 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.
Which drywall is best for soundproofing?
There are various drywall types, but the Type X drywall is the most commonly used for soundproofing. It is a fire-resistant board, and a board of 5/8″ thickness can resist fire for an hour, which concurrently makes it the best drywall to reduce noise.
Is drywall more soundproof than plywood?
Drywall is the most cost-effective and the most noise-reducing since it has the most mass. Plywood is the least effective since sound transfers quickly through the wood.
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 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 much does drywall reduce sound?
As such, it takes a 10dB reduction to reduce the perceived “noise” by 50%, 20dB by 75%. etc. By increasing a standard wall's STC from 34 to 64, there is ~30dB of transmission loss, which would provide an 88% reduction in perceived sound coming through the wall.
What is an STC 50 wall?
1 January 1. 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.
Is an STC rating of 50 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. These terms and definitions are related to Sound Transmission Class and will help provide the full picture of how sound is measured.
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.
What does an STC rating of 50 mean?
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.
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.
Can you add STC ratings?
You can't add STC ratings together. For instance, if you have an STC of 40 on one wall and decide to add another wall with an STC of 20, the STC of both walls combined will not be 60. Instead, the STC will be calculated using logarithms, and will probably produce a rating of about 45.
What insulation has the best STC rating?
mineral wool insulationLastly, you'll find mineral wool insulation with the highest STC rating of around 45. This rating blocks out more sound than any of the other forms of insulation, classifying it as the most soundproof of them all.
What is a STC rating?
Sound Transmission Class (STC ) is an integer rating of how well a building partition attenuates airborne sound. In the USA, it is widely used to rate interior partitions, ceilings and floors, doors, windows and exterior wall configurations (see ASTM International Classification E413 and E90).
What is STC in a wall?
In 1961, STC was introduced as the method for comparing various wall, ce iling, floor, door, and window assemblies. STC is calculated by taking the Transmission Loss (TL) values tested at 16 standard frequencies over the range of 125 Hz to 4000 Hz and plotted on a graph.
What is measuring STC good for?
Sound vibration decreases as it travels from one side of a wall to the other. To understand the value of STC ratings, we need to quantify and measure this loss.
How many decibels is a lower STC 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.
What is STC measurement?
In short, STC gives you a rough idea of how much sound a wall, for example, might stop. STC is the most common sound reduction measurement in use. As common as this measurement is, it is quite limited and should not be totally relied upon for real-world soundproofing expectations.
How to calculate STC?
Calculating STC involves adding something called "deficiencies" and utilizing the STC contour In the table you supply the Transmission Loss data. Then you add the STC contour adjustment to attain the adjusted transmission loss. Then you basically play with numbers in the "STC you wish to test column" until one of the two limiting conditions listed below are met. The highest number that satisfies both of those conditions is the STC.
Does STC factor bass?
It is an incomplete measurement since STC ratings do not factor low-frequency bass, which is where most noise problems occur. Please don’t rely on STC values alone when specifying a soundproofing system. We've learned that a high STC-rated wall may suffer terribly in the low frequencies and is therefore not a true solution.
What is the STC Rating of Drywall?
When it comes to STC ratings, we get asked more times about drywall than most other materials. This is mostly because drywall is the universally employed material of choice for interior walls here in the United States.
What is the Best STC Rating for Walls?
The “best” STC rating for walls is going to be dependent on the intended purpose of the rooms those walls enclose and how important or necessary blocking the transmission of sounds is to those using the rooms.
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 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.
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 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 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.
What is the STC rating for single pane windows?
A standard, single pane window, offers an STC rating in the range of 26-28, and you can add a few points with well constructed dual pane windows, but if you want to substantially reduce the amount of sound entering through the windows, you should consider adding acoustical window inserts. They easily mount over your existing windows, ...
What does an STC rating of 50 mean?
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. It is also the point at which respondents to surveys begin a drastic reduction in noise related complaints.
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.
How can I improve my STC rating?
The easiest way to improve your rating is by adding mass to the walls to increase the overall thickness of the walls. Adding insulation or air space inside walls also hinders sound from passing through the walls. For example, two four inch walls separated with a two inch gap would transmit less sound than a solid eight inch wall.
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 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 is STC in soundproofing?
Meanwhile, STC is really just an “approximation” of how much sound a wall blocks. It does not tell you the wall soundproofing ability at very low frequencies, which are not included in the STC calculation. Cinema soundproofing, for instance, must consider 50-80 Hz sound transmission, which may not be relevant in hospitality and multi-family applications. For unique applications, an acoustic engineer should be used to determine the appropriate STC and frequency-specific soundproofing needed for walls.
What is STC 50?
The most common single rating search for across the internet is STC 50. That is because it is one of the few STC, or Sound Transmission Classification, ratings that are mandated by building code. Particularly, in the International Building Code, STC 50 is required for dwelling units to adjacencies.
How to achieve high STCs?
High STCs may also be achieved by using a vinyl barrier (such as mass loaded vinyl) in the wall to improve soundproofing performance, especially
Does the building code apply to hotels?
It should be noted that this building code does not apply to hotels, offices, and other applications, which are instead generally designed per brand standards and acoustic best practices.
Is a STC 50 wall sufficient for an apartment?
An STC 50 wall may be sufficient for apartment-to-apartment, but may be well below the expectations of a high-end condo. Some litigation refers to “commercially reasonable” expectations of the clients.
