How to Soundproof French Doors – 8 Practical Methods

Are you irritated by the noise coming through your glass doors? Are you wondering how to soundproof French doors?

It’s hard to deny it – French doors are amazing. They’re styling and classy. Even the most basic model looks much better than ordinary-style doors, adding warmth and style to your home. 

Unfortunately, French doors also have a downside. The mostly glass doors are notorious for letting a ridiculous level of sound in. With some models, particularly those that don’t have double-glazing windows, you can hear almost everything happening outside. 

Luckily, it doesn’t have to be. You can soundproof French doors to at least greatly minimize the noise they let in, if not block it almost entirely. 

In this guide, you’ll discover how to soundproof French doors. The advice I give applies to both interior and exterior French doors. 

What you need to know before soundproofing French doors

Before I show you how to soundproof your French doors, I must first explain why you hear the sound through them in the first place.

And it’s all because of the way French doors are made. 

(This also means you improve their soundproofing qualities by targeting some issues.)

How noise travels through French doors

Most of the sound you hear through French doors is called airborne sound.

Airborne sound waves are created when sound travels through the air. Take speaking, for example. The sound of your voice makes the air vibrate. Then, that sound travels through the air until it reaches the person you’re speaking to.

Music, TV, radio, dog barking, and cars passing by your house are other airborne sounds.

Because airborne sounds travel through the air, they also enter houses similarly. That’s one reason you hear louder sounds from the outside with doors open. Closing them immediately reduces the intensity of the noise because, with closed doors, there are fewer places through which the sound can enter.

This brings us to the next thing –

How sound enters through closed French doors

Unfortunately, it does so because of how French doors are made…

First of all, most such doors are larger than ordinary doors. They feature light construction, with the majority of the doors being taken by glass. 

(By the way, this applies to both traditional French doors and sliding doors. There is no difference between them in that regard.)

The additional window panels on each side of these doors shown below might be an extreme example, yet they illustrate the problem well. Most of the wall in this room is glass.

Here’s why it’s a problem.

First, the doors are larger, meaning more entry points for the sound. With ordinary doors, most of the area around them is a wall. And although walls can let noise in, it’s never as much as what’s coming through the doors. 

You have more gaps and cracks in more oversized doors through which air and airborne sound can get in.

(This is important to remember. As you’ll shortly see, you’ll focus on those gaps when soundproofing those doors.)

The other problem is that French doors are made mostly of glass. Unfortunately, this makes them poorly soundproofed by default.

Glass lets more sound in than most other building materials. Even a double-glazed window isn’t completely soundproof because the glass will let sound in. That’s because, by nature, glass has low acoustic properties regarding different frequencies. 

This also means you’ll need to use external materials and several soundproofing techniques to soundproof French doors. 

Here’s how to do it.

How to Soundproof French Doors: 6 Methods for Interior and Exterior Doors

• How to Soundproof Glass Doors: A Comprehensive Guide

#1. Seal all gaps and cracks

As I said above, gaps are the first thing you should target to reduce the noise coming through French doors.

And let’s face it—whether your French doors are brand new or have been in the house for years, they will have small cracks and gaps. Even a tiny gap of a few millimetres will allow an incredible amount of noise into the house. 

To put this in perspective, research shows that covering just 1% of gaps in the surface can result in up to a 10% drop in noise!

Imagine the results after filling in the gap between the door frame and the floor. 

How do you soundproof those gaps?

Use an acoustic sealant, ideally the Green Glue.

Green Glue is one of the best acoustic sealants on the market. It works just like any other caulk. You apply it with a caulking gun directly on the crack. Your goal is to fill it, just like you would with any other gap. However, given its soundproofing qualities, Green Glue does more than fill the crack. It also prevents various sound frequencies from entering.

Get Green Glue

#2. Add soundproof weather stripping to the frame

Once you’ve filled in all the cracks between the frame and the wall, the next step is to do the same for the frame.

In this case, however, you don’t fill in cracks by applying a sealant but by adding weatherstripping. But let’s take it from the top.

Your doors might also have gaps between the actual door and frame. These might result from poor manufacturing or because the hinges have slightly tilted with long-term use. As a result, the door doesn’t create a full seal with the frame when you close it, leaving microscopic space through which air and noise can get in. 

Luckily, the solution is simple: Attach self-adhesive weather stripping to the doorstop, the sides, and the top of the frame. 

EXAMPLE: Soundproof Weather Stripping Door Kit

#3. Add a door sweep at the bottom of the door

This is another simple method to increase the soundproofing of your door frame. The biggest gap is likely at the bottom of the frame. Installing weather stripping is one way to solve this. 

However, you can also experiment with adding a door sweep. 

A door sweep is an element you add to the bottom of the door that continuously closes the gap between the door and the floor, even when the doors are in motion. Door sweeps are perfect for retaining heat, keeping cold air out, and blocking sound. 

#4. Hang soundproof curtains to block the noise

Clear: Despite their name, soundproofing curtains aren’t fully soundproof. This doesn’t mean that they do not help with noise reduction. Quite the contrary. Soundproofing curtains can reduce the intensity of many outside noises entering your house. When you hang them, noises like traffic, barking, and other loud sounds that might bother you will be much quieter. 

This is due to certain characteristics of soundproofing curtains:

• Thickness – Such curtains are much thicker than the usual ones. Because of that, they absorb or block many frequencies from getting in. 
• Length—Soundproofing curtains are also very long, typically reaching the floor. This leaves no additional space for the sound to travel.
• Density – These curtains are also incredibly dense, absorbing more sound. 
• Rough surface – Finally, soundproofing curtains have a rough and porous surface. This prevents sound from bouncing off them and increases their volume. Rough surfaces absorb part of the sound energy and reflect only what they cannot absorb. This means that the sound that reaches your ears is usually much quieter than without those curtains.

Check out the best soundproofing curtains here

#5. Hang moving blankets

Hanging moving blankets over French doors is the same way as using curtains.

Thanks to its inherent sound-absorbing quality, the blanket will naturally absorb some sound waves trying to enter your room through French doors.

Just like with curtains, thickness plays the most crucial role here. The ideal moving blanket to soundproof French doors should be as thick as possible. Ideally, it should also feature grommets by which you could hang them on the curtain rod. It should be large enough to cover as many French doors as possible. Otherwise, you run into a risk of a significant amount of the noise rolling off it by its edges and still entering the house.

Here’s an example of a large and thick moving blanket that you could use to soundproof French doors.

#6. Soundproof air vents above the door

Many French doors have built-in air vents at the top, and there might also be separate air vents in the walls around the door. 

Those vents help improve air circulation in the room and let the sound from the outside in. Moreover, air vents might reduce the effectiveness of any other methods you use to soundproof the French door. 

After all, they will continue letting sound in. So, regardless of how well you fill in gaps and cracks, the noise will bother you because of the air vent. 

One way to soundproof the air vent is to remove it and dry the gap. But I admit it’s not always ideal to do it, and it might affect air circulation. 

The other option is to create a maze inside the air vent.

The whole concept looks like this:

Notice how air (and sound) can no longer pass through the vent with the maze in place. The maze makes it more difficult and requires the sound to bounce from one surface to another, reducing its intensity and volume with each bounce. 

The simplest method of creating the maze is to install wood or drywall panels inside the air vent, creating a structure like the one in the image above.

Here’s a great video showing how to create a simple DIY air vent.

#7. Lubricate hinges and handles

This may not be a method of blocking outside noise, but it’s also something we often forget. Hinges and handles can create quite a noise, only adding to the frustration of poor soundproofing of glass French doors. 

Hinges and handles will not move quietly without oiling and squeaking whenever you open the door. 

The solution to this problem is quite simple – Oil the hinges. You can use any oil – vegetable oil, machine oil, you name it. 

You can also get a proper hinge lubricant like Liquidfix. It comes with a dropper and a needle pack so that you have everything you need to do a good and clean job out of the box.

#8. Replace your current french door with a double-glazed french door

This is, by far, one of the most effective ways to eliminate your noise problem. Unfortunately, it is also the most costly one. Hence, I’ve left it till the end.

When you’ve replaced the current door with a double-glazed one, you immediately increase the thickness of the glass. Thicker doors automatically place a much sturdier barrier for the sound to enter the room.

One way to think about it is that double-glazed French doors and any curtains or moving blankets you might cover them up with will place more resistance on the sound’s path than your current ones.

Granted, you’ll most likely still have to seal any gaps and cracks around them, as these factors are independent of the door’s quality. However, you probably won’t need weather stripping as the new doors will naturally be well insulated.

And that’s it…

Use these six ways to soundproof your glass French doors and block the outside noise. 

Good luck!