I regularly get asked if Green Glue is worth the investment. If you’ve been researching a soundproofing project you might have come across the name and wondered the same thing. Well here’s a quick answer:
Green Glue, a brand of acoustic sealant, is definitely worth it. Not only is it ideal for sealing small gaps between materials, which sound can pass through, but it’s also great at dampening low-frequency sounds. It does this by converting them into heat energy.
In this article, I’ll go into a bit more detail about what exactly Green Glue is, how it works, and how you can use it in your soundproofing projects. Hopefully, by the end, you’ll be a Green Glue expert!
Check out my review of Green Glue.
What is Green Glue?
Green Glue is a brand name for a type of noiseproofing compound. This is how the company refers to it, but it’s essentially acoustic caulk.
Acoustic caulk is much the same as regular caulk: you can use it for sticking things together or sealing small gaps between materials.
But it has one significant difference: Green Glue includes sound dampening properties, meaning it contributes to noise reduction within a space.
Its main ingredients are viscoelastic compounds, which are materials that cure but don’t harden. This means that Green Glue does bond surfaces together but never completely hardens like normal caulk.
These viscoelastic properties are what makes it such an effective sound dampener: when sound waves come into contact with the product, it doesn’t allow them to pass through. Essentially, Green Glue prevents the sound waves from causing vibrations.
The science behind it is this: sound waves cause molecules in materials to vibrate. This is known as shear force.
The shear force causes a ripple through a material (whether this is air or a solid object). This ripple is essentially a sound wave.
Sound waves vibrate through the surface but are stopped by the Green Glue because it remains elastic.
The caulk’s elasticity stops the shear force in its tracks because it resists the up-down movement that sound waves cause.
In turn, the vibrational energy is converted to heat energy, as it expends its force trying to make the Green Glue’s molecules vibrate.
As I mentioned previously, Green Glue is just a brand name. You can get other types of acoustic caulk, but Green Glue is probably the most well known.
Using it in a soundproofing project can make a surprising difference to the level of noise transfer, but obviously, you’d never use Green Glue on its own.
Remember, it’s basically a type of sealant, and so is only going to improve other methods you use. For example, it’s great at sealing drywall sheets together but wouldn’t do anything on its own.
The Pros and Cons of Using Green Glue
Generally speaking, Green Glue is all positive. But there are some minor cons to consider when using it in your next soundproofing project.
Here are the main pros and cons of Green Glue for soundproofing.
Works against low frequency noises
A major drawback for many soundproofing products is that they’re mostly effective against higher frequency noises.
This is true for solutions such as adding more mass to a structure.
Green Glue, however, is effective at low frequencies, which expend less energy when moving through objects.
This means it’s a useful addition for dealing with frequencies between 80 and 100Hz.
Helps to seal joins and gaps
Along with its sound dampening properties, Green Glue is ideal for sealing small gaps, such as between sheets of drywall or mass loaded vinyl (Amazon link).
Sound waves act much like heat in the sense that they can pass through even the smallest gaps.
Therefore, to effectively soundproof a space, you need to ensure all these small gaps are sealed.
Using Green Glue for this job works on two levels: it physically seals the gap and provides a level of sound dampening too.
It works against both impact and airborne noises
Because of its elastic properties, Green Glue can reduce both impact and airborne noises.
It’s particularly effective at reducing the ability of sound waves to pass through a rigid structure, such as drywall or flooring.
It can’t be used on its own
This isn’t really a con but is worth considering nonetheless. Green Glue can’t be used as the only soundproofing material in a project.
For best results, Green Glue should essentially be the finisher after you’ve applied plenty of mass and other dampening materials.
It takes around 30 days to cure
Again, this isn’t a major con, but Green Glue takes about 30 days before it’s completely effective.
As I mentioned, it’ll never fully dry, but don’t expect peak results before 30 days.
If you’re planning a quick soundproofing project, don’t rely on Green Glue for immediate results.
It’s not actually glue
Although the name might say otherwise, Green Glue isn’t actually glue. It’s a dampening compound that can be used as a sealant.
In short, don’t think you can use it to stick down mass loaded vinyl or drywall. You’ll still need to rely on traditional glues, nails, or screws for this kind of work.
If you’re adding Green Glue to your wall, apply it and then fix the material over it within 15 minutes of the first application.
It’s not cheap
While you can buy it from a number of sources, Green Glue doesn’t come cheap.
If you’re planning a large soundproofing project, be prepared to expand your budget.
That said, buying in bulk will help reduce costs. This 5 gallon bucket of Green Glue (Amazon link) is expensive but is more cost-effective than buying smaller amounts.
How to Use Green Glue
For the most part, using Green Glue is as simple as pointing it at the surface and squeezing the trigger.
However, there are some useful tips that make the process easier.
Here are my main tips for how to use Green Glue.
- Be sure to lay down plenty of newspaper or dustsheets because Green Glue is nearly impossible to clean up.
- For best results, apply it to the rear of a drywall sheet and then seal any gaps between sheets.
- While it isn’t toxic, always ensure your work area is well ventilated and you’re wearing proper safety equipment.
- Buy a dispensing gun (Amazon link) for the easiest application.
Finally, it’s worth knowing what kind of area you can cover with Green Glue. Of course, this’ll depend on the amount you buy, but here are some rough figures.
I recommend using a whole tube of Green Glue (about 29 oz.) per 16 square feet of material.
This works out as roughly 2 tubes per 4 x 8 ft. sheet of drywall based on you applying it between cracks and across the backside of the sheet.
Of course, this is just a rough guideline. You can be as liberal with it as you want, but I wouldn’t recommend being any more sparing than the measurements I’ve given above.
Some Final Thoughts
In short, Green Glue is definitely worth the investment. I find it’s the best way to finish off a soundproofing project because it adds that final stage of sound dampening.
Have you had any positive results using Green Glue? Let me know in the comments below!