When it comes to insulating your home, sound may be a part of the decision-making process, especially if you live in an apartment building, on a busy city street, or if you’re planning on working from home with loud kids in the other room.
Does house insulation help with soundproofing?
In general, any form of insulation added to the walls in your home will muffle the sound coming in to some degree. The question is, how much will it muffle it? Soundproofing is all determined by the Sound Transmission Class rating (STC). The higher the rating, the more soundproof the material. When picking the best type of insulation for your home, you should consider the STC rating of your options if sound levels are important to you.
Types of Insulation and thier STC Rating
The Typical Interior Wall has an STC rating of 34
Closed-Cell Insulation has an STC rating of 37
Fiberglass Insulation has an STC rating of 39
Mineral Wool Insulation has an STC rating of 45
What type of insulation is the best for soundproofing?
A typical interior wall with ½” of drywall on either side has an STC rating of 34. When adding closed cell spray foam insulation to it, your STC rating will increase to 37. This means that you’ll likely be able to hear loud speech but muffled so you won’t necessarily understand full conversations.
Fiberglass (or traditional) insulation falls in the middle range of options bringing the STC rating to 39. This option provides so a bit more privacy and blockage from sound entry. Open cell spray foam ties with standard fiberglass at an STC rating of 39 as well.
Lastly, 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.
While the ratings can go as high as 60+ for specific and primarily soundproofing materials, often with multiple layers, the best and most effective soundproofing insulation option will be the mineral wool. If soundproofing is a high priority for you when it comes to choosing the best insulation for your home, it may be worth considering combining different types of insulation on your interior walls to increase your STC rating.