Having thin, hollow doors in your home can be a real nuisance when it comes to noise.
Whether it’s the loud TV from the living room, music blasting from your teenager’s bedroom, or just general household sounds, those hollow doors do little to block the noise.
If you’re looking for a way to soundproof a hollow door and restore some peace and quiet, you’ve come to the right place.
In this blog post, we’ll explore several effective methods for how to soundproof a hollow door. First we’ll do the science bit, but if you want to get straight to the soundproofing options, skip here:
- How to soundproof a hollow door: Best options
- Add mass
- Seal air gaps
- Install a door sweep
- Dampen vibrations
- Replace with a solid core door
- Combining multiple methods
Why do hollow doors transmit more noise?
To understand why some hollow doors need soundproofing, it’s essential to know how sound travels.
Sound waves are transmitted through solid objects, such as walls and doors, as well as through air.
Hollow doors, with their thin, lightweight construction, offer less resistance to sound waves, allowing noise to pass through easily.
Hollow door vs high mass door
As we’ve illustrated in the graphic below, a higher mass door can reduce decibel (dB) levels significantly more than a hollow door:
The basic idea is – that a door with higher mass, such as a solid core door or a door with mass added, may provide a sound transmission rating (STC) of 40.
That means it will shave off 40 dB from a noise level of 80 dB. To put 80 dB in context, that’s around the level of road noise, a busy office or a cocktail party.
Normal hollow doors give you an STC of around 25 dB, which does a much poorer job of cutting noise. Therefore, for front doors, or doors which are at the entrance of a noisy room, adding mass to your door or installing a solid core door can really make a difference.
Methods for soundproofing a hollow door
Now that we’ve covered the importance of soundproofing and how sound travels, let’s explore some practical methods to soundproof your hollow doors:
Add mass
Increasing mass with soundproofing blankets or panels is one of the most effective ways to soundproof a hollow door.
The more mass a door has, the better it will be at blocking sound waves. You can achieve this by installing soundproofing blankets or panels on the door’s surface.
Soundproofing blankets are thick, dense materials made from materials like mass-loaded vinyl or specialized fabrics. These blankets can be hung over the door or attached using velcro strips or other adhesives. They work by absorbing sound waves, preventing them from passing through the door.
Another option is to use soundproofing panels, which are rigid boards made from materials like fiberglass or mineral wool. These panels can be cut to size and mounted directly onto the door using construction adhesive or specialized mounting clips.
Seal air gaps
Even the smallest gaps or cracks around your hollow door can allow sound to pass through. To prevent this, it’s crucial to seal any air gaps using caulk or weatherstripping.
Caulk is a versatile sealant that can be applied around the door frame, filling in any gaps or crevices. Look for acoustic caulk specifically designed for soundproofing purposes, as it offers superior sound-blocking properties compared to regular caulk.
Weatherstripping, on the other hand, is a flexible material that can be installed around the door’s perimeter, creating an airtight seal when the door is closed. Common options include foam, rubber, or vinyl weatherstripping, which can be easily cut to size and secured in place using adhesive or nails.
Install a door sweep
Door sweeps fit easily at the bottom of doors, keeping out noise. One thing we always preach – sealing gaps is essential to soundproofing. And when it comes to gaps around your door, the bottom of the door is often the biggest offender.
They are cheap, won’t obstruct you from opening or closing the door, and can do a good job of cutting the noise level coming through. You can get basic ones, which are U-shaped and made of materials such as rubber or vinyl, and metal types that screw to the bottom of the door.
There are additional benefits, too. Door sweeps can reduce drafts, block out light, and stop bugs from entering.
Dampen vibrations
Using Green Glue or other damping compounds is another way to reduce sound transmission through a hollow door.
When sound waves hit the door, they cause it to vibrate, which in turn generates additional noise on the other side. By applying a damping compound, you can dissipate these vibrations, minimizing the amount of sound that passes through.
Green Glue is a popular damping compound specifically designed for soundproofing applications.
It’s a viscoelastic material that can be applied between two layers of drywall or other materials, effectively converting the energy from sound waves into heat, reducing their transmission.
To use Green Glue on a hollow door, you’ll need to remove the door from its hinges and apply the compound to the inside surface.
Then, you can cover it with an additional layer of material, such as mass-loaded vinyl or soundproofing panels, creating a damped, multi-layered barrier against noise.
Replace with a solid core door
If you’re willing to invest in a more permanent solution, consider replacing your hollow door with a solid core door.
Solid core doors are constructed with a dense, solid material at their core, such as wood or mineral-based components, making them much more effective at blocking sound than their hollow counterparts.
While this option may be more expensive and labor-intensive, it offers superior soundproofing performance and can be a worthwhile investment if you’re serious about reducing noise levels in your home.
Combining multiple methods
For maximum soundproofing effectiveness, consider combining multiple methods.
For example, you could install a solid core door, seal any air gaps with caulk and weatherstripping, and then add a layer of mass-loaded vinyl or soundproofing panels for added mass and vibration damping.
By combining several soundproofing techniques, you can create a multi-layered barrier that effectively blocks sound waves from multiple angles, ensuring optimal noise reduction.
Choosing the right method for your needs
When deciding which soundproofing method to use, consider factors such as:
– Your budget
In general, replacing your hollow door with a solid core door will be the most expensive method. Adding mass with MLV or soundproofing blankets will be in the mid-range. And a simple door noise reducer such as a door sweep is among the cheapest.
– The level of noise you’re dealing with
If it’s a front door that is letting in the noise, a quick fix such as a door sweep is only likely to partly solve the problem. Solid core doors can make sense for a front door, but ensuring you seal all the gaps is also important.
When noise is coming from a room within your house, you may be able to significantly cut the dB level by adding mass with MLV or a soundproof blanket.
– The level of soundproofing you desire
To achieve what some might call a ‘100% soundproof’ door, you are going to need to think about installing a solid core door while adding weatherstripping to ensure that it is completely airtight.
To make a big difference to external noise, consider using one or more of the other soundproofing methods suggested in this piece.
– Keeping it practical
Additionally, think about the practicality of each method. If you’re renting or plan to move soon, you may want to opt for more temporary solutions, like soundproofing blankets or weatherstripping, which can be easily removed or reinstalled in your new home.
Soundproofing a hollow door can be a game-changer when it comes to reducing noise levels in your home.
By understanding how sound travels and implementing the appropriate soundproofing methods, you can create a more peaceful and tranquil environment, free from unwanted noise intrusions.
