One of the most common questions we receive at Soundproofing America is "How do I soundproof my door?". Soundproofing a door is a rather simple process, however there are certain key procedures that need to be adhered to for maximum soundproofing.
First and foremost, the door needs to be a solid core door, one made of MDF (medium density fiber), fiber filled, or even a solid wood exterior door. Now we realize that in many cases a door cannot be replaced due to aesthetic reasons, or because a Co-op board or condo association will not allow such a change in an effort to maintain uniformity within the complex. In this case there are methods and procedures that can be adhered to, that will dramatically reduce the amount of noise that is passed through a hollow core door.
On most doors the common sound leak areas are around the perimeter of the door where it closes into the door jam, and down at the bottom where there is usually a gap that prevents the door from sticking when it is closed into the jam. A great method for checking for sound leaks is to light up the room on the opposite side of the door, then close the door and darken the room that you are attempting to soundproof (with the door closed of course). This will show you just where the breeches are in the door/door jam assembly. The gaps around the perimeter of the door can be treated with a closed cell foam tape that is adhered to the door jam precisely where the door actually closes into the jam. This also acts as a weather seal for the door.
Next we want to attack the gap at the bottom of the door. A threshold is generally recommended (one with a weather seal is preferred) and from that point you would install a precut transom seal to the lower back side of the door which will act like a door sweep until the door is completely closed, thus forming a seal at the bottom of the door where the transom seal butts up against the threshold.
We generally do not recommend soundproofing a hollow core door, however there are things that can be done to these doors that will maintain the aesthetic value and still give you some remarkable results. Please call us toll free or on our convenient New York number for further information on how to sound proof your doors.