How to soundproof your door with a simple acoustical soundproofing door sweep. (Click Here for Printer Version!)
This is All About Controlling Sound and Reducing Noise coming through Doors.
We sell hundreds of these door bottom gap sealers to hotels, motels, bed and breakfasts and apartment buildings for cheap door soundproofing – take a tip from them!
After dealing with the exterior sound coming thru windows, sound control efforts in a room should focus on the door: a typical interior hollow core door will pass sound quite readily. (An STC of much less than 20- this means conversation can easily be heard thru it).
The door should entirely be replaced with a solid, exterior door, the thickest you can find. “MDF” (Medium Density Fiberboard) doors are cheap and have good sound blocking qualities and available from Builders Supply like Home Depot. Get a door without the recessed decorative panels- they reduce the thickness of the door. If it’s important to have them, buy some that you can attach onto the door. Make sure the door is well fitted to the frame, no gaps or crevices for sound to migrate through. If there are gaps, use our closed cell PVC tape, (not from the hardware store). The door should be sealed off as if it was 40 degrees below zero on one side. If it has a gap over 1/4″ at the bottom, use our door sweep seal, (a metal strip with a rubber flap) mounted to it, available from us. (As shown here). Set it to just brush the floor. [BUY] If your door is a standard 36″ wide, you can get it and a roll of sealing tape for $36 Free Shipping!
A seal is essential to properly soundproof a door. Our soundproofing seal is a rubber loop, carefully cut to your door width size, modified by us with sealed ends for added performance in creating a dead air space within the loop. We’ll cut this to an exact fit for your door if you’ll give us the measurement of the width of the door.
You will also receive the screws to mount it to your door. Depending on if it’s metal, you’ll need to drill pilot holes, if wood you won’t. Usually, only a screwdriver and a few minutes is needed to install this very much needed attachment to block sound from coming from underneath your door.
Some notes about our “Soundproof Door Sweep”: (The part that should seal the door bottom against sound and that fits on the edge of the bottom of the door). Since our doorsweep only seals up to a 3/4′ gap, a transom seal should be used from the hardware store that fits on the floor across the bottom of the doorway. Use this kind if you have a huge gap. Try to get one with a rubber flap. (Mechanical ones are expensive and will eventually fail).
Note, the illustration above would tend to make some believe the seal fits somewhat under the bottom of the door- not so- it just hangs down and does not slide under the door!
Remember- it won’t close the bottom door gap over 3/4″, if more, use the above mentioned threshold to take up some of the gap or build down the bottom of the door with a wood strip.
Sometimes it may take both!
This wood strip was mounted with glue and screws using drilled pilot holes to avoid splitting the wood. It was then painted to match the door finish.
The seal should lightly brush the floor, but a 1/4″ gap is acceptable when you are done.
Your new door may still need sound insulation. Use 1/8″ MLV with 1/4″ closed cell foam, bonded to it. Then cover with “Super Soundproofing acoustical mat”. Usually 1″ thick will suffice. Cut it a bit oversize to cover the seam of the door at the frame to help seal it. You can use the mat with the adhesive backing but you may not be able to remove it later.
A typical door 3′ X 8′ is 36 sq. ft. so 8′ of the 4′ wide MLV will cover it. 9′ of the 4′X1″ foam will be needed. If there’s a lot of sound still coming through, consider hanging a “Mass Loaded Curtain” (barrier) or a acoustical curtain over the door and frame.
You could use gaskets that are ordinary thermal sealing gasketing foam strips from the hardware store, but far better results can be had if you use our “Super Soundproofing 1/8″ Thick Self-Adhesive Tape” , because it is a closed cell material, will seal better and is much more durable. It is a gray tape in widths of 1/4″, 3/8″ & 1/2″ for door sealing. Apply strips on top of each other to build up and close wide gaps.
Think you can’t replace the door with your door, Landlord problem? You can always put his door aside and rehang it when you leave. Better, create an “Airlock door system” by leaving his door in place and adding another door to the frame, opening the opposite way. (Solid core, of course!)
TIP: Remove the molding from around (use care to not split it!), the door and check the gap between the frame of the door and the rough framing. Usually you’ll find there is nothing there! Many times this empty space of the door frame has no insulation at all, just covered by two pieces of wood molding. Pack the area with our Super Soundproofing Mat (you can order just a few feet, we have no minimums), or use our caulk, and cover the gap with our lead tape, then replace the molding. This tip applies to windows too! (Do not use expandable foam as for thermal insulation. It will be worse than the airgap, establishing a soundpath).
Sliding doors have little or no acoustical qualities at all and are best replaced with one that has, or if not possible, covered with a hanging sound barrier such as curtains, etc. If it’s a glass patio door, you could cover part of it with soundproofing mat and make a holding panel with mat attached to it to cover the door that moves when it’s shut.
Another option is to add another patio door with a new frame. This double door will block a lot of sound by trapping air between the door panels. Commercially available soundproofing sliding glass doors can be had here. But you can do-it-yourself!
Open doorways? Curtains hung across open doorframes usually don’t perform well acoustically, but do some sound blocking if they are heavy and fitted well to the frame. If made of clear plastic and cut into strips for egress, the strips need to be overlapped about 50%. When using clear plastic, use the heaviest you can, we have it in up to .160 thicknesses. Acoustical curtains perform about the same. If possible, consider hanging curtains on BOTH sides of the doorway for greatly improved sound reduction. This is because the dead air trapped there works for you. Such curtain installations should touch the floor. Use double-sided tape to attach the curtains to the wall at the edges to help seal the curtain.
Garage doors are another problem, especially bad if they are segmented doors. (Panels that are hinged). Such doors may prove difficult to deal with because of the gaps created by the hinging. However, our “Super Soundproofing Mat” glued to the inside may flex enough to work O.K. Use as thick of material as you can. It will also help to use a barrier like “Super Soundproofing Flooring” (MLV) to cover the entire door area including the walls to outside. (More on this on the web page about soundproofing a garage).
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