French doors are often very elegant and classy. But one problem with them is the noise. Since they’re larger than regular doors and also thinner due to the glass, they pose a really easy entrance point for sound. For this reason, they often require some soundproofing to minimize noise and ensure greater privacy.
How to Soundproof a French Door
In order to soundproof a french door (and any other door for that matter) two things have to be done:
- door has to be made thicker by adding more mass to it (mass blocks sound)
- any gaps and cracks in or around the door have to be sealed (sound moves with air, so any uncovered gaps will let it walk right through the door)
Those are the only two things required in order to soundproof a door. But there are different methods and materials that can be used to accomplish them. So in this article I want to share with you the best methods that I’ve used and researched to get the job done:
1. Hang a noise blocking curtain
Noise-blocking curtains come in different sizes and colors. This wide range of choices makes them very handy for any soundproofing project that involves doors and windows.
There are large one panel and two panel noise-blocking curtains available that can be used on french doors and windows. Always make sure that they’re large enough to cover the entire door or window area.
To hang them, you’ll need to install a curtain rod from above the door first.
If you’re dealing with a lot of noise, I recommend installing a double curtain rod. This type of rod allows you to hang two curtains at the same time, which will double the noise reduction.
You could do this on both sides of the door. However, this can be a bit too much, both from an aesthetic viewpoint and in a practical sense. Because it can get annoying to deal with too many curtains. So I would stick to placing one or two just on one side of the door.
If you’re interested in this method, check out my full guide on noise-blocking curtains.
2. Hang a thick moving blanket
Moving blankets are very similar to thick curtains. Some of them have grommets so you can hang them on a curtain rod or hooks with anchors. Or they can be tacked or glued to any surface, including walls.
The thicker a blanket is, the better noise reduction you can expect from it. So how would you use a moving blanket to soundproof a french door? Well, it should be one that’s extra thick and it should have grommets for hanging on a curtain rod.
While this a solid option if you have one or two at home, I think curtains are a much more elegant solution. And their price is very similar so if you’re buying right now, I suggest getting curtains instead.
But if this is something you’d like to explore further for other doors, I suggest using a heavy blanket. Supreme Mover blanket is the heaviest one on the market.
3. Install a double-glazed french door
Replacing your current french door with a thicker, double-glazed door would almost completely solve the problem. You’d still probably need to take care of the gaps surrounding the door (I’ll explain that later), but you’d take care of the “mass” part of the equation.
What I mean is that you’d no longer have to make the door thicker by using any soundproofing materials like curtains or blankets. Although they could be used additionally for better sound and thermal insulation.
However, this is a very expensive and labor-heavy project. You’d have to buy a new door and then have a few people who are very careful remove the current door and install the new one.
It goes without saying that you’d need to get the new door custom-made to fit the size of the frame. So while replacing the door is a good option if you’re up for it, it’s certainly not the easiest or the most affordable one.
Don’t install material directly on the door
So those are the methods for adding mass and thickness to the door area. The reason why I don’t recommend placing soundproofing material directly on the door is because of the glass.
You don’t want to ruin the appearance of the door by covering the glass with acoustic panels or anything like that. But hanging curtains or blankets a bit away from the door can be a neutral addition or even a positive one in terms of aesthetics.
When picking out the noise blocking curtain or blanket, make sure that the color and the overall design matches the style of the room.
4. Cover the gaps between the door and the frame
What are these gaps? Well, you’ll notice that parts of the door frame where it meets the door can be quite thin. And there can even be a millimeter or a few millimeters open gap left even when the door is closed, because to this.
Close the door and see if you notice these gaps around the hinges and on the other side. Above the door as well. By sealing these gaps with dense foam tape, it’s possible to cut down on the noise by a lot.
Even if you add mass to the door by using other methods, if these weak points are not taken care of, a lot of noise will still pass through. So to get this done, cover these gaps with dense foam tape that is thick enough for the job.
Self-adhesive, high density foam tape is the best option. There are also different sizes available. I suggest measuring the width and the depth of the gaps and getting the foam seal that would fit best. But even if it’s too wide, you can always cut it to the needed size with a sharp knife.
Sealing these gaps will act as both sound and thermal insulation. Two birds with one stone!
Those door frame gaps are not the only ones to worry about. There’s also the gap under the door.
Perhaps it’s not present under your doors, but it’s worth checking out. Again, even the smallest of gaps can let air (and sound) pass through.
To cover this bottom gap is incredibly fast and simple. All that is required is a cheap door sweep.
So no tools are needed to install it. Just stick it to the door and you’re done. You could of course use small nails or screws to make sure that it’s permanently fixed to the door, but it holds well even without doing that.
Aside from preventing drafts and noise, it will also prevent bugs from entering the room. If you live in an area where scorpions and spiders are a concern, this is something I recommend doing even if just to prevent those pests from coming inside. The alternative is to move to Alaska.
However, if you have an uneven floor, a basic door sweep can drag on the floor and even prevent a door from opening or closing properly. In that case, installing an automatic door bottom would be a better option.
These bottoms use a mechanism that recognizes when the door is opening and closing. So they cover the gap only the when the door is closed.
Installing an automatic door bottom is more difficult and requires some woodworking skill and tools. But if you’re dealing with an uneven floor it’s the only functional option.
Having said that, here’s a full guide on door bottoms. It covers the best basic and automatic door bottoms, and how to install them.
6. Lubricate the hinges and door handles
If your french door is making obnoxious squeaks every time you open and close it, lubricating the hinges will likely fix it. You can use any machine oil to get this done. This guy used gun oil to lubricate squeaky hinges and it seems to be working really well.
If you don’t have any machine oil at hand and you’re desperate to do this, use any oil. Even vegetable oil poured carefully on the hinges (you don’t want to make a mess) can fix the problem. Vaseline can be used as well. But machine oil is cleaner and lasts longer as a lubricant.
7. Don’t forget to soundproof the air vents
Are there any air vents surrounding the door? If yes, you’ll probably be disappointed with the results if you don’t soundproof them as well. Above-door air vents are huge gaps that will make any door soundproofing project fail if they’re not addressed.
So how to do it? The most effective way is to remove the vent and drywall the gap in the wall completely.
But if you want to keep the air vent functional, while also reducing the amount of sound that can pass through it, creating a sound-maze is the best option.
This is done by gluing small pieces of wood inside the air vent so that the noise has to bounce against them before it can pass through to the other side. This way it’s volume and intensity is significantly reduced.
Check out my air vent soundproofing guide to learn how to do this.
Conclusion: Soundproofing French Doors
Adding mass and sealing gaps is what any soundproofing project boils down to. But as you’ve just seen, locating these gaps and using proper mass-adding material is crucial for great results.
You can accomplish all of this with and spend less than $50. Or you could spend more. It depends on how many of these steps you need to implement in order go get great results. Hope this helps!