Super soundproofing using Mass Loaded Vinyl (MLV) gained popularity in the 70s. The 70s had a flurry of musicians that often caused noise disturbances in other rooms. Super soundproofing was the key to rehearsing while people in other rooms were able to maintain a peaceful atmosphere. The concept of MLV layering on dry walls works if the mass of the wall is increased. If it is, the acoustics are accentuated and the noise reflects back into the room, decreasing the sound that escapes into other rooms.
How it Works
The noise-reduction is rated in terms of Sound Transmission Class (STC). Most dry walls, with average thickness around the US, have an STC of around 36. Most companies that produce MLV have an average MLV layer mass of 1 pound per square feet and the STC that it is said to have is around 26. According to popular belief, it is said that adding a layer of MLV to dry wall would increase the STC by adding both STCs up and the result would be super soundproofing for the room.
The truth in that claim has been debated for years with very few substantial and valid researches earning recognition worldwide. The research has found that other materials, like Gypsum Board, has more STC than MLV but adding that to a dry wall has been found to increase the total STC by a mere 2 or 3 points. It has been seen that if the walls are thickened a bit on both sides and a layer of MLV is applied on the wall on both sides, it can lead to noise reduction to around 15%, which is substantial.
There are questions about the cost effectiveness of MLV. The application of MLV requires extensive labor. The vinyl is unrolled, cut by hand, applied around edges of the dry wall, and attached with fasteners and tape and so on. All this labor increases the cost of buying MLV from around $1 dollar a square foot to $5 a square foot. The difference is significant and can affect your budget dramatically. For example, if you are building a new house, you may not be able to fit the cost into the budget.
All in all, the use of MLV for super soundproofing has remained popular over the years because it reduces noise, if the application is done right. However, the argument against MLV is that the only reason it is still used today is due to lack of awareness because other materials may work better. Despite the popularity of MLV, it’s labor, cost and effort should be compared with the use of other materials before making a decision on what to use to soundproof your room.