If you are like me and prefer peace and quiet then there are many reasons why you would want to soundproof a hollow door. Whether it’s those noisy neighbors or even noisy house-mates, soundproofing is a good way to cut out the commotion.
Most doors in modern homes are made by cladding a basic rectangular frame with thin, pressed wood sheets. They are light, cheap and easy to install. The disadvantages are that they are flimsy and offer almost no soundproofing and will invariably let noise in (or out).
But, you can do it yourself with some every day tools, a little bit of patience, plus some cheap items that you can pick from Amazon.
If you follow my guide to how to soundproof a hollow door, you will be able to reduce the overall noise in your home. Continue reading on and I will show you exactly how you can do it yourself.
3 Easy Steps for Soundproofing a Hollow Door
When soundproofing a hollow door, there are three areas that need to be focused on. There’s the actual door itself, the sides of the door and the opening at the bottom.
Step 1: Choose the Right Sound Deadening Materials
There are many different sound deadening materials that people will recommend you use for the DIY soundproofing job, but don’t let anyone else confuse you. The two that I recommend are closed cell foam and MLV (mass loaded vinyl).
You simply need to choose one of these products. The foam is cheaper, but the MLV will work better so depends on how much money you want to spend on soundproofing the door.
Handy Hint: I find that MLV provides around 20% more soundproofing based on my own projects I’ve done in three properties.
If you want to buy cheap, then your foam you will need to buy a high-density, closed cell foam that will block out both low and high frequency sounds. This foam is low cost and usually comes with an adhesive backing to help installation. This product can be ordered here on Amazon.
Spend a little more money, and you will get slightly better results with MLV (known as mass loaded vinyl). Again, this is a high-density material that combines nylon and barium sulfate.
The nylon is soft and can compress whereas the barium sulfate has a high mass which increases the density. Do you really care about the science behind it though, probably not, but just know, it works, and very well!
MLV is more expensive than the foam and it does not have an adhesive backing. However, it is more effective as a soundproofing material. You can order my recommended MLV again on Amazon.
Step 2: Dismantle the Door Panels
Take the door off the hinges and lay it down on the floor.
Before we do anything though with regards to removing the panels to expose the hollow element, I want you to consider the hinges.
When you add soundproofing materials into the hollow spaces, it’s going to increase the weight of the overall door. With that in mind, you might want to upgrade your hinges to ones that can take any additional weight.
The original hinges that hold and hang your hollow door in place might not be able to handle the additional load that we are going to add, so think about investing in some heavy-duty hinges – just make sure that they are going to fit properly.
Handy Hint: As with everything though, you might want to test it out with the original hinges, I just want to make you aware that it could be heavier leading to some hanging issues inside of the door frame.
But now onto the really crux of the matter; soundproofing the hollow area.
You will need to remove one of the thin pressed wood panels. Be sure to only remove the panel that is facing the source of the sound. This can be done by gently prying the layer off the frame.
I always find that a paint scraper works really well to remove panels. Many times you will find that glue has been used to fix the panel to the frame.
Handy Hint: Be careful not to damage the panel when prising them off, as the panels on hollow doors are notoriously lightweight and flimsy.
Step 3: Place Your Chosen Material into the Door Cavity
After the door has been dismantled and you have the panels off you can cut and measure out your chosen soundproofing material; either closed cell foam or MLV.
Make sure that the material fits tightly in the door cavity before sticking it as any gaps will dramatically reduce the effectiveness of your sound insulation.
Handy Hint: Dry to double-up, or even triple-up the layers of material inside of the hollow door to get the best sound deadening results.
If you are using a material that does not have an adhesive backing then green glue (see on Amazon), is your best option. It’s really good as it not only sticks things fast, but also acts as a sound insulator. You will also need a caulking gun, these are similar to the applicators used to apply silicon.
Before placing the panel back onto the frame, add some green glue to the wood frame as this will create and extra sound deadening results. Effectively you are decoupling the panel from the door.
And that’s it.
It is pretty simple.
But wait, just because you have soundproofed the hollow door, does that mean it’s going to completely block and stop noise coming in and out.
Probably not, and I will explain why, with some additional steps you should now take.
Extra Things You Should Do
Whilst you have now learned how you can soundproof a hollow door, there’s still space around the door itself where sound is going to enter.
Noise, just like water does, will find any gap, crack, or space, and then exploit it.
What you will also need to do is fill those gaps, or at least take steps to insulate them.
The Frame (Top and Sides)
You know that rubber that you get inside of car door? Well, you can do something very similar with internal house doors too, using some rubber strips that sit inside of the frame at the top and both sides. It’s commonly known as weather-stripping.
This type of stripping is rubber and are thick enough so that when the door closes it will compress the rubber gasket creating a soundproof seal. These strips often have an adhesive backing to make installation easier.
It’s really cheap, available on Amazon, and really simply to fit inside of the door frame.
The Gap Under the Door
And lastly, you will need to address the gaping hole at the bottom of your door as all your efforts up until now will be rendered useless if this is not dealt with. It’s the main areas where sound and noise is going to come in.
The best way to seal the bottom area is to use a flexible silicone panel that comes with an adhesive backing. Again, they are ridiculously cheap on Amazon.
I have soundproofed hollow doors time and time again using these tried and tested methods. I promise you that anyone can do it, as long as you have the tools, patience, and can buy the cheap materials referenced in this guide.
After doing it, you should finally have some peace and quiet. Remember that sound is measured on a logarithmic scale and reducing the sound by only 10 decibels will result in a perceived noise level reduction of 2x!