We get calls and emails all the time regarding how to block sound through walls, ceilings, floors, and windows, yet it surprises me how often doors tend to get overlooked.
You can add all the layers of mass-loaded vinyl and gypsum to your wall that you want to, but if you have even a 1% gap opening when the door is closed, you are losing a substantial amount of the sound-blocking capability in the wall you just created. Yes, that’s right, a 1% gap opening can reduce the effectiveness of the door by 50%. Below are some proven methods for soundproofing a door assembly using door seals.
Seal Up Gaps With Door Seals
Door seals can be a very effective means of stopping sound from getting through a door. For a standard door, there are basically three parts that are needed for the door to be sealed on all four sides.
Door Jamb Seal
Automatic Door Bottom
- Jamb seals attach to the sides and top of the door jamb. These are available in versions that either attach to existing door jambs or actually become the door jamb in the case of a new construction build.
- An Automatic Door Bottom can be attached to the bottom of the door to seal off the bottom edge. The advantage of an automatic door bottom over the typical door sweep that you can purchase from a building supply store is that the automatic door bottom is mechanical. As you close the door a plunger mechanism on the side of the door bottom is engaged, dropping the seal down to the floor. This gives you a nice tight seal whenever the door is closed. Door sweeps do not seal as well and can allow for small gap openings like those mentioned at the beginning of this post. Automatic door bottoms are available in surface-mount, semi-mortised, and fully mortised versions so that you can choose the look that best matches your application.
- In most cases you will want to use a good quality Threshold in conjunction with the automatic door bottom. This way the door bottom has a solid surface to seal onto. If the area the door bottom is sealing to is a hard surface like concrete or tile you may be able to get by without one. If it is carpet you are definitely going to want a threshold and even in the case of hard flooring substrates mentioned previously, a threshold is still recommended for the best results. Like the door bottoms, thresholds can be made in a number of different ways; some are simple and flat while others can be taller and have seals of their own to create a double seal when used in conjunction with the automatic door bottom. The former are typically used in high traffic areas or when ADA certification is needed, while the latter are typically used in applications involving high noise levels like recording studios, server rooms, or industrial applications.
Door Seal Kit
For standard-sized (3’0″ x 7’0″) doors we make a door seal kit that gives you all the necessary parts above that are pre-cut and ready to install. In addition to the parts referenced above, Astragal Seals can be used in the case of a double-door setup where you need to seal up the area where the two doors meet in the middle. These seals are available for double doors with two active leafs or one active leaf. One type of door that cannot be sealed well is a pocket door. Because of the way this type of door operates, it is next to impossible to seal efficiently, and is not recommended for a door application where sound transmission is a priority.