Whether you are dealing with a noisy dishwasher or you just want a soundproof wall, there are many products available that you might use. There are rigid styrofoam sheets, expandy foam, various types of soft foam, fiberboard, etc. Most of these materials will provide a slight degree of soundproofing, and different materials will block sound at different frequencies.
But when it comes right down to it, nothing beats the general soundproofing characteristics of a certain material that you probably didn’t even consider…
Once upon a time, I witnessed my father spend a LOT of time trying to insulate a noisy dishwasher. The soundproofing material of choice was rigid styrofoam panels. They were cheap, and surely they would work…
Well, they did – to an extent. Given the amount of effort put in to the soundproofing process, the return on the investment of time and money was rather abysmal. Of course, you might just go out and buy a new dishwasher that is already properly insulated. Newer mid-range models are generally very quiet. But at least in this day and age, money doesn’t grow on trees!
Fiberglass insulation – the spongy kind that comes in rolls – is absolutely your best bet. Thin fiberglass bats are inexpensive, and the insulative properties of fiberglass with regards to temperature also make it the perfect soundproofing material.
Fiberglass insulation was invented in 1938 by Owens-Corning. It is created by melting sand and glass and then using one of several processes to “spin” the molten glass into a network of thin interlocking fibers. Although the fibers themselves conduct heat rather well, the manufacturing process results in millions of tiny air pockets between the fibers. It is these air pockets which give fiberglass insulation its excellent insulative properties – as well as its fire-resistant characteristics. Since sound waves travel through air, fiberglass insulation also blocks sound really well. A layer of fiberglass insulation only 5cm (2″) thick will stop even a loud sound dead in its tracks. If you can fit more, go for it! Just be sure not to compress the fiberglass too much.
Another instance where you might want soundproofing is between two rooms in your house. Say you have two rooms that are joined by a nice framed door. Well, you’d like to use the two rooms as separate bedrooms, or perhaps turn the smaller of the two rooms into a storage closet. You don’t want to really tear out the door and replace it with a wall, because in the future when the kids are older and out of the house, maybe you’ll want to restore the door to it’s original state as your needs change. In any case, one thing is certain: you need good sound insulation between the two rooms. A hollow wall is a very poor sound insulator.
There is one quick and easy way to accomplish this in a semi-permanent fashion. First, on one side of the doorframe, nail or screw a nice piece of plywood into the door frame so that it completely covers the door. Now you have an ugly piece of wood covering the door frame. Not to worry: with some strips of wood trim and/or some paint and/or wallpaper, you can quickly and easily make the whole thing look far more presentable. You now also have an ideal location to mount a large, full-length mirror.
Now mosey over to the other room. Before you actually close the door, you’ll want to remove the door handle hardware. You’ll also want to buy a bat of thin fiberglass insulation. Cut a piece of fiberglass to fit snuggly within the door frame and up against the unfinished side of the plywood. Stuff it in good, and then close the door. Voila! You’re done.
Of course, if you’re separating two bedrooms, remove the door from the frame, remove the hinges, and simply mount a sheet of plywood on either side of the door frame, filling the cavity in the middle with more fiberglass. Store the door and hinges in plastic sheeting in your attic for future use.
This may seem like a lot of work, but it’s actually very easy to return the door to it’s original configuration. You simply remove the plywood, fill in any nail or screw holes with wood putty (which is a combination of real wood powder and epoxy), and then put a fresh coat of paint over the whole door frame once the putty has dried. Then just remount the hinges and door if necessary, and you’re back in business. I’ve done this before, and the results are a lot nicer – and easier to accomplish – than you might think!
Fiberglass insulation is used to insulate boilers, hot water heaters, hot water storage tanks, water distillers, and many other appliances and gizmos. For soundproofing plus insulation without breaking the bank, it’s hard to beat!
Important Health Notice:
When handling fiberglass insulation, always wear gloves, eye protection, and use a high quality respirator. The lightweight, tiny glass fibers WILL float around in the air, and you don’t want them stuck to your skin, eyes, or inside your lungs! When your project is finished, use a shopvac to vacuum your work area thoroughly, vacuum your clothing, wash your clothing, and take a shower to remove any remaining fibers from your body.