When it comes to soundproofing, both brick and drywall have their own unique pros and cons. To determine which material is best for your specific needs, it’s important to understand the differences between the two and how they can affect the overall effectiveness of your soundproofing efforts.
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Brick vs Drywall for Soundproofing
Brick on its own is a much better soundproofing and insulation material than drywall because of its thickness, but it’s also much more expensive and harder to install. Drywall, however, can achieve similar soundproofing results when combined with other materials, such as rockwool, to further reduce sound transmission to a similar level to that of brick.
There’s a lot more to this and I will definitely go over all of it in this article, so let’s get to it!
Brick: The Pros
One of the biggest advantages of using brick for soundproofing is its durability and longevity. Unlike drywall, which can be easily damaged or punctured, brick is a much sturdier and more resilient material. This makes it ideal for soundproofing applications in areas that are prone to wear and tear, such as high-traffic areas or areas that may be subjected to impacts or other physical stresses.
In addition to its durability, brick is also a relatively heavy material. This added weight can help to absorb sound waves and reduce the amount of noise that is able to pass through a wall. This is especially true if you use multiple layers of brick, as the added weight of each layer can help to further dampen sound waves.
Brick: The Cons
While brick has some clear advantages for soundproofing, it also has some notable drawbacks. One of the biggest disadvantages of using brick is its cost. In general, brick is much more expensive than drywall, and the added cost of using multiple layers of brick can quickly add up.
This may make it difficult for some homeowners to afford the cost of using brick for soundproofing their walls.
Another disadvantage of using brick for soundproofing is its weight. While the added weight of brick can be beneficial for sound absorption, it can also be a drawback in some cases. For example, if you are trying to soundproof an existing wall, the added weight of multiple layers of brick may be too much for the wall to support. In this case, you may need to reinforce the wall before you can safely install brick for soundproofing purposes.
Drywall: The Pros
Drywall, also known as gypsum board or plasterboard, is a popular choice for soundproofing because it is relatively inexpensive and easy to install. In most cases, drywall can be easily attached to an existing wall using screws or nails, making it a convenient option for homeowners who are looking to soundproof their walls without having to spend a lot of money.
In addition to its low cost and ease of installation, drywall is also a relatively lightweight material. This makes it ideal for soundproofing existing walls, as the added weight of multiple layers of drywall is unlikely to cause structural issues.
Drywall: The Cons
While drywall has some clear advantages for soundproofing, it also has some notable disadvantages. One of the biggest drawbacks of using drywall is its lack of durability. Unlike brick, which is much more resilient and less susceptible to damage, drywall can be easily punctured or damaged by impacts or other physical stresses. This can make it less effective for soundproofing applications in high-traffic areas or areas that are prone to wear and tear.
Another disadvantage of using drywall for soundproofing is its relatively low weight. While the lightweight nature of drywall makes it easy to install, it also means that it is less effective at absorbing sound waves. This can make it less effective at reducing noise levels compared to heavier materials like brick.
What is the STC (Sound Transmission Class)?
STC, or Sound transmission class, is the rating used in the US to describe how well a building partition can attenuate sound, such as interior partitions, ceilings, floors, doors, windows, etc.
In most other countries, the Sound Reduction index is used (SRI).
The STC rating reflects the decibel reduction of noise that a partition can provide (1 STC is equivalent to 1dB reduction), where a higher number, or rating, equals better results, or overall attenuation.
Here’s a table showing what each STC rating represents:
| STC | What can be heard |
| 25 | Normal speech can be understood |
| 30 | Loud speech can be understood |
| 35 | Loud speech audible but not intelligible |
| 40 | Loud speech audible as a murmur |
| 45 | Loud speech heard but not audible |
| 50 | Loud sounds faintly heard |
| 60+ | Good soundproofing; most sounds do not disturb neighboring residents. |
There are multiple factors that go into calculating the STC rating, such as the acoustic medium, mass, sound absorption, and more, of the materials, but I won’t go into too much detail about this since it doesn’t pertain to the article itself.
Usually, an STC tied only to a specific material is a useless figure because the combination of materials used is more important and it’s what gives you the actual STC.
STC Rating of Brick
Brick is a relatively heavy and dense material, which makes it effective at blocking sound. As a result, brick walls typically have a relatively high STC rating. The exact STC rating of a brick wall will depend on factors such as the thickness of the wall, the number of layers of brick, and the type of mortar used. In general, a double-brick wall with a thickness of at least 10 inches and a high-quality mortar will have an STC rating of around 50 or higher.
STC Rating of Drywall
A typical interior wall with ½” of drywall on either side has an STC rating of 34 on its own, but much better results are yielded when combining the drywall with other insulation materials, such as rockwool or fiberglass which, when put inside the interior wall made of drywall will increase the STC rating to about 45 when using a single layer of drywall, and you can always add another one on top!
Flame Spread Index
While this article focuses mainly on sound insulation, I think that it’s extremely important to address whether drywall or brick can be considered a fire hazard or not, which is determined by the flame spread index.
The flame spread index is determined by the distance that a flame travels along a test substrate in a specific timeframe to determine its propensity to burn and how rapidly it can spread flames.
It’s divided into these 3 classes:
| Class | Flame Spread Index |
| A | 0-25 |
| B | 26-75 |
| C | 76-200 |
- Class A fire ratings indicate a flame spread rating between zero and 25. Materials that fall into Class A or Class 1 include; brick, gypsum wallboard, and fiber cement exterior materials. These materials do not burn well and are very unlikely to contribute fuel to a fire.
- With a Class B or Class 2 fire rating, the flame spread rating would fall between 26 and 75. This rating is typical for slower-burning whole wood materials, such as planks that are in the same form as they were when they were cut from the tree.
- A Class C or Class 3 fire rating has a flame spread rating between 76 and 200, which incorporates building materials like plywood, fiberboard, and hardboard siding panels, as well as any of the faster burning whole woods.
What is a good flame spread rating?
The lower the Flame Spread index the better, since this means that the flame won’t travel and spread as rapidly. Class A materials, which have a rating of 0-25, do not burn well and are very unlikely to contribute fuel to a fire, which makes them the safest ones.
Flame Spread Index or Drywall vs Brick
The flame spread index of drywall, also known as gypsum board or wallboard, is typically around 25 or less. This means that drywall has a low to moderate rate of flame spread, and is generally considered to be a non-combustible building material.
Brick also has a flame spread index of 25, which is to be expected since we all know that brick can’t really burn (unless exposed to really high temperatures for an extended period of time).
Out of the two, however, brick definitely comes out ahead since drywall is made out of paper and only has flame-retardant chemicals in its makeup to prevent fire from spreading too quickly: Usually provides about an hour’s worth of time before it burns, whereas brick can’t really catch on fire.
Conclusion
Both brick and drywall have their own unique advantages and disadvantages when it comes to soundproofing. In general, brick is a more durable and effective material for soundproofing, but it is also more expensive and difficult to install. Drywall, on
Last Updated on December 3, 2022 by Facundo
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