Blackout curtains and soundproofing
A common question asked is if blackout curtains help with soundproofing at all.
In a sense yes all blackout curtains will reduce sound in a way but it will vary greatly between the types of curtains and how they were made. A curtain panel being blackout most of the time means that no or less than 1% of sunlight can come through the curtains. This nicely also means that there is far less room for sound to go through the curtains with no resistance. However if the curtains are quite thin it doesn’t matter if they are soundproof or not as the curtain in general can’t stop any sound. There has to be some sort of layer of fabric to stop the sound. If a curtain lists specifics like foam backing and/or several layers of coating then it will provide at least some soundproofing.
GSM is for paper!
You may have seen stacks of paper with GSM information on it but a bit surprised to see it listed while shopping for curtains. GSM known as grams per square meter is actually used for not only paper density but fabric density as well. When looking at the GSM listed on curtains the higher the number the more dense it is which in return can help block more sound and possibly more light. Common thin curtains will display a GSM of around 140 which is like the same as a t-shirt. Now if you compare a cotton t-shirt to a wool sweater, one keeps you far more toasty and feels a lot heavier. Wool can have a GSM of up to 550 GSM in some cases so right there you can see what kind of a difference the two numbers have. There are varied amounts of GSM per curtain and there really isn’t a standard GSM on certain fabrics. So while manufacture A has a 300GSM curtain with velvet, manufacture B can have a 200GSM curtain with velvet. If comparing two similar curtains that don’t have GSM listed, look at the weight of the two as it may show quite the difference. A much heavier curtain can mean a much more dense use of the fabric.
Sound, sound, and GSM.
This is a obvious thought in a sense because a higher GSM is going to block more sound in most cases. Curtains with a higher density is much harder for sound to sneak in compare to low density curtains. A quieter night for you with higher GSM curtains!
Will a low GSM curtain let in light?
Not exactly. It can help in some regards to determine if light will go through but you’ll also want to look at the fabric being used and the weave. Every manufacture is different with how they make their curtains with the same fabric. Some may have a different weave, use multiple different fabrics, or have multiple layers compared to the other. If unsure always read reviews listed on the seller’s site to see if anyone’s noticed any issues with light. A much higher GSM though will have a significantly lower chance of letting in light due to the density in general.
In the end.
On the final thoughts of GSM, the unfortunate fact is that not all curtains will list their GSM amounts so trying to compare two similarly made curtains in detail may not work. While typically a higher GSM will block more sound additional factors like the weave and type of fabric being used can make quite the difference.
A common question is how much noise can actually be reduced by soundproof curtains. Before we can answer this however we must look at a term used to rate soundproofing materials like curtains, drywall, and windows. STC or also known as Sound Transmission Class is a rating of how well airborne sound is eliminated by the object in question. In other words, it can approximately tell you how much decibel reduction in noise you will get. We’re going to dive into a bit more detail than we normally would in this post so just be warned it may not make as much sense the first time through.
Quick decibel levels comparison
20dB – Watch Ticking
30dB – Whisper
60dB – Normal Conversation
70dB – Busy Street
90dB – Lawn mower
Drywall, windows, and noises
While in your house a typical layer of drywall with no insulation you’re looking around an STC of 30. This is also known as a paper thin walls because a person on the other side of the wall can hear you talking. So take a normal conversation decibel level of 60dB minus STC of 30 which you’re left with 30dB. Note that different frequencies can affect how much noise is actually reduced. As for windows a single-pane glass window will have an STC of between 20-25 which is doesn’t provide as much sound reduction as one would hope.
The top of the line industrial strength soundproof curtains can have a STC rating of up to 35. Unless you’re looking to really stop the noise and spend the money you unfortunately will have to settle for living room curtains which won’t provide as great of an STC rating. A really good set of curtains will probably have a STC rating of up to 15 while you’re most likely going to get between 5-10. Now this may not seem a lot at first but your perception of increases or decreases in decibel levels can weigh in on how much noise is actually being reduced. Plus of course the more layers of noise reduction materials you setup between you and the problem the decibel levels can only go down.
Looking at a quick example of a noisy street, having 70dB can be reduced on average by 20 by a window and then again by 10 by curtains. You’ve reduced the noise down to almost a whisper which is more enjoyable to sleep to though you can reduce it even more with foam, double-pane windows, and an additional set of curtains.
While looking into soundproofing a room you may want to investigate how the noise is coming in. In this quick tip we’ll go over a very common overlooked issue of holes and cracks. Not only can spending 30 minutes fixing these issues help reduce outside noise but also reduce heating and cooling costs.
Around windows look for cracks or various small holes that could either lead to the outside. Even the small crack could make a difference as it maybe much bigger further in where you can’t see it. Make sure that the window or windows close properly to create a tight seal. If you can feel air coming in see where and do what you can to stop it but if it’s really bad you may want to invest some money in some new windows.
If you are a handyman(or woman) and are able to easily take off/put back on the trim around your window you can do a further investigation. Some spare materials you may need is insulation and caulk. Builders tend to shim to make your windows level and also square. Now unless the builder decided to spend additional time covering everything that was going to be covered by the trim you may come across several gaps. Usually if the builder knows these gaps will be covered by the trim later so they will not bother trying to cover anything behind them. If however you find holes or cracks you can fill these gaps with some insulation and then cover it up with some caulk. If living in an older house check to make sure there is no rotten wood as this may degrade later if left alone.
Overall not only will doing this help eliminate noise but reduce heating and cooling costs. Remember that where there’s airflow sound has a much easier time entering your home.
Here is a soundproofing quick tip dealing with acoustics.
When talking about acoustic soundproofing or acoustic treatment of a room you are looking to improve the quality of sound within the room itself. This is done by breaking up the sound waves and so there is less reflections/bouncing of sound which in return helps eliminates things like echo. Common types of materials that can do this are various foams, certain types of ceiling tiles, and even egg boxes. However just because you are able to put up foam or egg boxes doesn’t necessarily mean that noise from the outside will be blocked. This is a very common misconception that putting up acoustic related items will have the same effect as soundproofing materials.
If you are looking to help stop noise from within the room itself foam and egg boxes can help greatly. You may also want to look at removing various objects in the room that have just a flat surface as sound loves to bounce of these. But if you are looking to stop noise from the outside world coming in, lining your ceilings and walls with egg boxes won’t be able to do what you need. It may reduce it slightly but most likely it won’t be enough if soundproofing is what you’re looking to accomplish. A good sturdy set of curtains will help a lot more against a single-pane window than egg box city. You may also want to invest in soundproof drywall if sound coming in is a huge issue.