Automatic Door Bottom - Mortised

Automatic Door Bottom - Mortised

Sound Rated Fully Mortised Basic Automatic Door Bottom with high quality neoprene seal, fills gaps up to .75". Available in aluminum mill finish, in standard stock sizes (Can also be trimmed on the field).

Special Discounts apply to orders over $500.00 See Product Descriptions for details.

Price: $56.59
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Made in USA
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This soundproof Fully Mortised Automatic Door Bottom will provide an excellent seal needed to retain your door's sound rating. The aluminum casing is fitted with a self-extinguishing and oil resistant solid neoprene insert which serves as its primary seal. Additionally, the interior of the aluminum anodized casing is filled with rubber for extra protection.

This product is designed to be fully mortised into a wooden door. It is great for designer doors and high end, luxury condos, since the appearance of the door is not altered. It is non-handed and can be applied directly over the floor surface or above a doorway saddle, though a saddle is recommended for higher sound control (A saddle is highly recommended when the door bottom is sealing onto carpet). Available in aluminum mill finish and in standard stock sizes. Installation instructions and screws provided.

Not sure what size you need? See How to Measure for an Automatic Door Bottom.

Custom Sizing: Custom sizes up to 60" can be purchased through our office. Pleases contact us at 845-388-1200 to purchase.

How it Works:

This product utilizes a concealed flat mechanism which is activated by the pressure of closing the door (The brass nut at the head gets pushed in by the door jamb and that lowers the seal).  The high quality neoprene rubber seal drops, filling gaps up to .75”, upon the closing of door to create a tight seal and raises up automatically when the door is opened to ensure smooth door operation. Our door bottoms have been tested through 5 million cycles and provide the same excellent quality as our surface mounted and semi-mortised automatic door bottom. For more information, see About Automatic Door Bottoms.

Automatic Door bottom can be trimmed on the field up to 3-4" depending on the size ordered, see installation guide tab.

Note: We recommend trying to keep the gap between the door and the floor at no more than 3/8" for maximum sound sealing. Larger gaps can be treated with a door saddle, or an added wood strip to the underside of the door.

This model is recommended for interior residential doors. For situations requiring a better seal please see our Mortised Heavy Duty Automatic Door Bottom.

For a surface mounted or semi-mortised version of this product, see our Basic Automatic Door Bottom.

Special Discounts on Our Door Hardware:

No Coupon Code Needed. Discount automatically applied when added to shopping cart.

Spend $500.00, get 5% off plus free shipping
Spend $1,000.00, get 10% off plus free shipping

See our Monthy Specials and Discounts for more great Soundproofing Savings!

Please note, images are for illustrative purposes only. They are not actual photos. Therefore, actual colors may vary slightly and size may be enlarged to show detail. See product specs for exact measurements.

Product Data
Installation Guide

Click here for a Printable Copy of How to Install an Automatic Door Bottom.

Automatic Door Bottoms are available with three mounting options: Surface Mounted, Semi-Mortised and Fully Mortised. A surface mounted application can be applied without removing the door from its hinges. For a semi-mortised, if the rabbet in the door is cut-out already, the door does not need to be removed. For a fully mortised application the door should be removed before starting.


  Once your door is ready for installation you need to determine the size required for your door bottom:
  • For a Surface Mounted Application: Measure the distance between the two stop moldings, or if a perimeter door gasket is applied,
    measure the distance between the two installed gaskets, then minus 1/8-1/4"” (.125”) from the total distance. That is the size needed for your door bottom.
  • For a Semi-Mortised and Fully Mortised Application: Measure your door from side to side; that is the measurement needed for your automatic door bottom.
For visual presentation see How to Measure for an Automatic Door Bottom.
How to Install an Automatic Door Bottom- Figure 1

Once you have determined the size needed, if necessary, trim your door bottom.
Use a chop saw or table saw to create a perfectly straight cut.

Note, Only trim opposite the actuating plunger, brass nut. (Trimming from the brass nut side will ruin your ADB).

How to Install an Automatic Door Bottom- Figure 1 You can trim from the edge up to one inch of the screw in the side wall of the ADB.  


How to Install an Automatic Door Bottom- Figure 3

Surface Mounted and Semi-Mortised models need to be applied to the push side of the door only (the side with the door stops-see Figure 3).
The actuating plunger needs to be applied to the hinge side of the door for all applications.

Place the automatic door bottom against the door

Once you have the automatic door bottom leveled and positioned correctly, with a pencil or marker mark
where the attachment screws need to be drilled.



How to Install an Automatic Door Bottom- Figure 4

To make installation easier you can drill a pilot hole which will ensure you attach the door bottom to the correctly marked spot (see Figure 4).
With the screws provided, screw in the automatic door bottom.

In some models, a plate is provided for the hinge side of the frame. This will protect the door frame from getting worn down by
the actuating plunger. If provided, attach to corresponding point on the frame.



How to Install an Automatic Door Bottom- Figure 1

Now that the door bottom is attached, test the door bottom by opening and closing the door to ensure there is a full seal.
If the seal does not come down far enough twist the brass nut out, if it seals too tight twist the brass nut in (see Figure 5).


Once you have followed through with all the instructions your Automatic Door Bottom is good to go! Enjoy years of quality sound, draft and light infiltration control with your new door bottom.

For additional assistance and product information, feel free to contact us. Our trained and friendly staff will guide you with all your soundproofing needs.

Shipping & Returns

Shipping and Return information is specific to this product page only (not for other products on our site).

  • Shipping:
    • Standard stock sizes (available above) ship within 1 business day.
    • For custom sizes ordered through our office, please allow 7-14 business days to ship.
    • FREE SHIPPING on orders over $75.00. There will be a flat $14.99 shipping and handling fee on orders under $75.00. - Applies to orders shipped within the USA (excluding Alaska and Hawaii).
    • Ships FedEx Ground.
    • Click here for more details on Shipping Information.
  • Returns:
    • Product can be returned in brand new condition within 30 days of purchase.
    • Please call or email us to receive an RMA number before returning. No returns will be processed without an RMA number.
    • Return shipping is customer's responsibility. Return address will be provided along with RMA number.
    • If you are shipping via USPS (not recommended) do NOT require signature as we will not be able to pick up your package from local post office facility.
    • Click here for more information on our Return Policy.
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Customers Questions and Answers

1) Al N: Color - does this product DSZ365D36 come in the dark bronze? Thank you, Al Newman

Trademark Soundproofing Reply: Yes. You can choose Dark Bronze from the dropdown.

2) Al N: Please provide the following information: on product# DSZ350A36 width? height? Bottom Lip size? Are screws provided? is the solid neoprene seal available? Thank you, Al Newman

Trademark Soundproofing Reply: .722w x 1.793h in inches

3) Steve Messina: Hi, I want to buy the 30" version of this. My door width measures 25" across. Can this be cut down to 25" and still work properly ? Or how about 25 3/4" ? What is the smallest width that this can be cut down to ? regards, Steve

Trademark Soundproofing Reply: We offer custom sizes. Please contact our sales dept or give us a call to place the order.

4) Karin Ch: Hi, do you count with 54" custom length for this door bottom line?

Trademark Soundproofing Reply: Hi Karin. A 54" model is available upon request. Please give us a call or email