Additional Information on Mass Loaded Vinyl
Limp barriers work better than rigid ones
The mass loaded vinyl barrier has to be somewhat limp, because the give prevents your barrier from vibrating. This is true whether you're installing the MLV inside the wall of a room in your house or under the carpet in your vehicle. Think about if you hit a sheet of lead (which used to to be the go-to blocking blocking material before we learned about the health concerns); it won’t reverberate and ring like a rigid sheet of tin or brass. It’s the same with mass loaded vinyl – the flexibility and limpness prevent the MLV from vibrating. Because the MLV material doesn’t vibrate, you don’t hear the ringing sound.
What should you look for in an MLV sound barrier?
The first thing you should confirm is the quality of the mass loaded vinyl. Two key indicators of quality are the MLV's STC rating and whether or not the company will describe it as odorless.
- The STC rating tells you how well the MLV blocks sound waves, the higher the better. The density of most MLVs is between 1 pound per sq ft to 2 pounds per sq ft. The industry standard is 1 lb, which is what we recommend for vehicles because the denser versions of MLV are not as workable around a vehicle's curves. Most people use the 1 lb density for homes as well. For this density, you're looking for an STC in the the 26 to 28 range.
- Being odorless indicates the quality of the materials that compose the MLV. It's possible to cut costs by making the MLV out of cheap recycled goods, but you pay for that cheapness in odor and blocking power.
Watch out for MLV made from low quality recycled products
Most MLV products are made from recycled goods. We are a fan of recycling, but it's important to make sure you're getting the best quality if its going into your living spaces. If you get the cheap-o MLV, some of the problems you can run into are:
- Inconsistent thickness, which can reduce the mass per square foot and reduce the effectiveness of your MLV sound barrier
- They can smell bad. Not in my car please!
- Can be more brittle and less flexible. You don't want the product to rip just because you bent it a couple of times.
- Sometimes its not even MLV! We've seen this occasionally with MLV material people buy in hardware stores.
Just do your research before buying.
Does mass loaded vinyl really work?
Mass loaded vinyl is a cost-effective, simple to install solution for soundproofing, or stopping noise from traveling between two spaces. The MLV must be installed with 100% coverage (no air gaps) and is most commonly used as part of a wall or ceiling assembly. Mass loaded vinyl is commonly used to improve the Sound Transmission Class (STC) rating of an assembly in both residential and commercial soundproofing projects.
Does mass loaded vinyl absorb sound?
Green Glue and mass loaded vinyl are both excellent soundproofing materials. Green Glue is always a better option if you have an existing wall, because it is much easier to install on top of a layer of drywall. Green Glue is also the preferred option for floors, typically used between two layers of OSB subfloor, because it will also improve the IIC rating of the assembly.
Mass loaded vinyl and Green Glue can both be used effectively in new construction, and will deliver similar overall performance (around an STC 50 with basic construction). We go into more detail on green glue vs mlv in our article if you want to learn more.
What do you put over mass loaded vinyl?
You should install 5/8” drywall over the top of mass loaded vinyl, after sealing the perimeter and around any penetrations with acoustical sealant. The drywall can then be painted or covered for whatever décor fits the room.
What is better than mass loaded vinyl?
A sound isolation clip system is always a higher performing option than mass loaded vinyl for wall and ceiling applications, as it will deliver superior STC and IIC ratings. RSIC clips should be installed with 25 gauge hat channel, 5/8” drywall, and sealed around the perimeter with acoustical sealant.
For floors, a rubber underlayment will perform better than mass loaded vinyl. Like MLV, it adds density to the soundproof barrier, but you get the added benefit of impact noise reduction.