I have a house and it has three floors. All of these floors and walls are made of concrete. So my question is, whenever the third floor makes noises, e.g. noises from music, carpentry tools like drills, or noises that are loud enough to hear, would the people from second floor able to hear noises from third floor given that the thing between/separates them is concrete? Or maybe worse, people from first floor? Thank you all!
3 Answers
When thinking about sound there are three factors: absorption, reflection and transmission [1]. Reflection leads to reverberation and echos. Transmission means the sound gets through and it is like the wall is not there. Absorption is where the sound "magically" disappears. It doesn't get reflected back nor does it make it through. Concrete is a rigid and dense material meaning it reflects sound well and does not transmit or absorb sound. Painted and plastered concrete is even more reflective and less transmissive [2]. Depending on the sound level and frequency, painted concrete floors and walls will prevent someone in the next room from hearing the sound. If you had a perfectly sealed concrete room with someone yelling at 100 dB, outside the room it would sound like a quiet conversation of about 50 dB. The reverb in the concrete room would be awful, but you could try and treat this with some soft low density material.
To directly answer your question, you will likely be able to hear the music and tools downstairs. If you replace the concrete with a different less dense material (e.g., wood), the sounds will get louder.
Concrete is a very rigid material and conveys sound fairly well. In most constructions, this is ameliorated by covering the inner structures with softer, more flexible materials. This includes wooden studding filled with insulating material and interior wallboard.
Floors can be covered with rugs or a wooden surface that is raised up from the concrete, often with insulating material below the surface.
How noisy and how problematic is very personal, and other factors will also come into play, such as the character and activities of the occupants (kids and parrots are notoriously noisier).
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So you imply that I should fill the concrete with inner materials so it won't make the sound escape? As what I've seen on a clip (I forgot the name), a man used a covering inner structures on a wooden floor, not on a concrete.– DeanMar 25, 2017 at 21:41
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Softer and isolating materials dampen sound on a wide variety of surfaces.– bibMar 25, 2017 at 22:04
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Oh I see what I need now. I think the clip that I saw can still be applied on this. Thanks man!– DeanMar 26, 2017 at 10:53
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Concrete is dense, as well as rigid, and has excellent sound transmission qualities (i.e., it does not transmit sound well). Concrete block gives about 50 dB of attenuation. Aug 30, 2017 at 14:37
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Best soundproofing is accomplished by using resilient channels such as the RSIC-1 by Pac International. There are other options that are proven, such as a double framed 2x4 walls with the studs offset and conventional fiberglass "weaved" between the studs. This method requires a bit of depth availability, though, so won't work in all instances. As usual, a lot depends on the budget and how much of a priority soundproofing is. In the real world trade-offs are a necessary compromise.
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I think your answer is more of suggestion. So, does it mean that even if it is concrete the sound would still pass through?– DeanMar 26, 2017 at 10:50