Heavy Duty Automatic Door Bottom

Heavy Duty Automatic Door Bottom

A high quality sound rated Heavy Duty Automatic Door Bottom with high quality solid neoprene or sponge neoprene seal, which can fill gaps up to .75". Can be applied as surface mounted or semi mortised application. Available in two anodized finishes, 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: $92.99
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Made in USA
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Weight 3.00 lbs

This automatic door bottom is specifically designed to create the best sound seal possible for normal sound levels. The aluminum casing is fitted with a self-extinguishing, closed-cell sponge neoprene or solid neoprene insert which serves as its primary seal. Additionally, the interior of the aluminum anodized casing is fitted with rubber for extra protection.

The mechanisim used in this ADB is of the highest quality and has been tested to over 5 million opening and closings!

The rubber used in this ADB is not cheap vinyl or EPDM rather it is long lasting neoprene.

The aluminum casing used is anodized 4 times to ensure a long lasting finish.

Sponge Neoprene vs. Solid Neoprene: Both seal materials have high sound control properties and are very durable. However, solid neoprene will hold up longer over the years and should be used when applied to high frequency traffic or rough floor surfaces, such as concrete.

This product is available as a surface mounted or semi-mortised application, as shown in the illustrations. 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 applied over a carpeted area). Available in two anodized finishes and in standard stock sizes. Installation screws and instructions 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. Please contact us at 845-388-1200.

How it Works:

This product utilizes a concealed flat spring mechanism which is activated by the pressure of closing the door (The brass nut at the head gets pushed in by the door jamb, which lowers the seal). The high quality neoprene rubber seal drops, filling gaps up to 1”, 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 mortised automatic door bottom. For more information, see About Automatic Door Bottoms.

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

Note, For maximum sound contrtol, we recommend keeping the gap between door and floor at no more than 1/2". Larger gaps can be treated with a door saddle or an added wooden strip to the underside of the door.

(See our High Sound Automatic Door Bottom for use in the most demanding situations e.g. recording studios). 

We have partnered with one of the biggest door gasketing manufactures and can offer any type of door bottom, saddle, gasketing etc. Including lead lined, mortised, fire ratings and custom sizes by calling our office at 845-388-1200.

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

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

Product Data

Click to Print Product Specs

Sponge Neoprene, Surface Mounted:

Surface Mounted Heavy Duty Automatic Door Bottom Compliant Ratings for Heavy Duty Automatic Door Bottom

Sponge Neoprene, Semi-Mortised:

Semi-Mortised Automatic Door Bottom Compliance Rating for Heavy Duty ADB

Solid Neoprene, Surface Mounted:

Semi-Mortised Automatic Door Bottom  Compliance Rating for Heavy Duty ADB

Solid Neoprene, Semi-Mortised:

Semi-Mortised Automatic Door Bottom Compliance Rating for Heavy Duty ADB
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.
    • Shipping is FREE in the USA (excluding Alaska and Hawaii).
    • Ships FedEx Ground.
  • Returns:
    • Product can be retured in brand new condition up to 30 days from date 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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Related products
Product reviews are only available to verified buyers of this product. To leave a review, please refer to the product review email we sent you.
  • Heavy Duty (4)
  • Attractive (3)
  • Easy To Install (3)
  • Effective (1)
  • Solid constructions and appear to be very sturdy (1)
  • Installation screws could be magnatized. (1)
  • Deteriorates Quickly (1)
  • It the spring bar broke while I was adjusting it (1)
  • Difficult To Install (1)
best uses
  • Interior Doors (3)
  • Reducing office noise. (1)
  • Exterior Doors (1)

Reviewed by 6 customers

Displaying reviews 1-6

By None

from Boone, North Carolina

About Me Professional office manager and engineer.

Verified buyer
Good quality door sweeps. Worked as advertised.
  • Attractive
  • Effective
  • Solid constructions and appear to be very sturdy
  • Installation screws could be magnatized.
best uses
  • Reducing office noise.
Comments about Heavy Duty Automatic Door Bottom:
Good quality product. Striker plate could use screws that are easier to install. Perhaps going with torex screws would help.
Bottom Line Yes, I would recommend this to a friend

By Jonathan

from Los Angeles, CA

About Me Professional composer.

Verified buyer
Poorly made. Broke while adjusting.
  • Deteriorates Quickly
  • It the spring bar broke while I was adjusting it
best uses
Comments about Heavy Duty Automatic Door Bottom:
This product seems cheap. After installation, I was adjusting the bolt that controls how low the sweep comes down and as I was unscrewing it, the entire bottom fell out. I thought I unscrewed it too far, but then I saw the piece of metal that acts as a spring was broken in half.

By Larry

from Maryland

About Me Avid Do-It-Yourselfer

Verified buyer
Muffles the Sound!
  • Easy To Install
  • Heavy Duty
best uses
  • Interior Doors
Comments about Heavy Duty Automatic Door Bottom:
Installed and cut with no problem but only thing is that the gasket is limited by the side plates so there is less than a 1/8" gap on each side. Might have been better to modigy the side plate so it would let the gasket protrude just enough to close that little gap on each side by the door seals.
Bottom Line Yes, I would recommend this to a friend

By ts

from brooklyn, ny

About Me Professional

Verified buyer
good product
  • Attractive
  • Easy To Install
  • Heavy Duty
best uses
  • Interior Doors
Comments about Heavy Duty Automatic Door Bottom:
easy to adjust and install, blocks sound well
Bottom Line Yes, I would recommend this to a friend

By pasha

from nyc

About Me Avid Do-It-Yourselfer

Verified buyer
Works as expected
  • Attractive
  • Heavy Duty
  • Difficult To Install
best uses
  • Exterior Doors
Comments about Heavy Duty Automatic Door Bottom:
Because of the width, had to change to a thinner less heavy duty side filler, as it was obstructing the door handle
Bottom Line Yes, I would recommend this to a friend

By Don

from Springfield, MA

About Me Avid Do-It-Yourselfer

Verified buyer
Very Good Product
  • Easy To Install
  • Heavy Duty
best uses
  • Interior Doors
Comments about Heavy Duty Automatic Door Bottom:
really helps to cut the noise transfer from hallway to office, made a considerable difference
Bottom Line Yes, I would recommend this to a friend
Displaying reviews 1-6
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Customers Questions and Answers

1) Fred: Will the ADB seal if the floor below the door is flat, but not level?

Trademark Soundproofing Reply: Hi Fred. Yes that would work. The mechanism is designed to drop one side first and then the other allowing it to conform to uneven floors (as long as it is not "U" shaped).

2) Steven: How do your products work with hollow metal doors?

Trademark Soundproofing Reply:

Hi Steven. All the Door Gaskets and Surface mounted Automatic Door Bottoms you see here will work just as well on a hollow metal door. We do also have ADB specially designed to fit into the hollow groove at the bottom of many metal doors. If that is something you are interested in please contact sales.

3) Mimi: Is this product mounted on the outside or the inside of the door? My building management has told me that I cannot install anything on the outside of the door. Thanks.

Trademark Soundproofing Reply:

Hi Mimi. This is mounted on the push side of the door which is usually on the outside. The only other option you have is using a Mortised Automatic Door Bottom which will not be visible however it would require you to mortise the door.

4) Mark N.P: Hi just curious how heavy is the in it's packaging when it's about to be shipped? Is it also 3lbs? How long would it take to be shipped to Connecticut, if ordered today?

Trademark Soundproofing Reply: Hi Mark, One piece shipped would be about 6 pounds. Ships same day if the order is placed by 1 pm ET and it is a one business day FedEx transit time. Thank You,

5) Alex S: Is the seal for a Heavy Duty Automatic Door Bottom and what would the cost be. Thank you Alex

Trademark Soundproofing Reply: Hi Alex, I am not understanding your question , can you please clarify. Thank You,

6) Verena S: Good morning, I would like to know the difference between the Sponge or Solid Neoprene Seal? I want the most acoustic possible, please.

Trademark Soundproofing Reply: Hi Verena. Both will work just as well. The sponge is more popular. Thank you

7) Brandon : Can these be made or cut to length? I have 40 doors in need of approx. 30" door bottoms. Thanks, Brandon

Trademark Soundproofing Reply: Hi Brandon, Yes we custom cut to size at no extra charge. It just takes a few days longer to ship. Please give us a call to place the order.

8) Luc L: Hi, How does it work if the floor is not level? Will it adjust it self to site tight on the floor? Thanks, Luc

Trademark Soundproofing Reply: Hi Luc, Yes the seal will self adjust to an uneven floor provided that it is in a straight line and not "U" shaped.

9) Sal: Door measures 22.75". Can it be cut to that size? Suggestion? Thanks.

Trademark Soundproofing Reply: Hi Sal. Not the ones that are 32 or 36 inch long. However we can get you that size please call or email us with the order.

10) Brandon Wood: What is the warranty on these units and the solid neoprene seals?

Trademark Soundproofing Reply: Three years against defects in material or workmanship.

11) Andy H: are these seals in dark bronze finish with solid neoprene seal in stock and ready to ship? what is the discount if i order 12? does the bronze finish come with color matched screws? thanks in advance for your help.

Trademark Soundproofing Reply: Hi Andy. The dark bronze is in stock, ready to ship and comes with matching screws (the end plates, which we don't recommend installing) are not color matched. Automatic discounts are applied to larger orders. Add to your cart to see the discounts.

12) James R: We have a gov project that requires STC 45 sound proofing. Do you know if these meet the STC 45 requirements?

Trademark Soundproofing Reply: Door seals can only maintain STC ratings of doors therefore your door itself must first have an STC rating of 45. That being said our heavy duty automatic door bottom when used in conjunction with our adjustable door gasket has been tested to STC 49 (and higher with the heavy duty).

13) Rick: What is the recommended door thickness for semi mortised installation. I will only have 1/2 inch remaining after semi mortising a solid door. The supplied screws are already too long.

Trademark Soundproofing Reply: Recommended minimum is 1-3/4" door thickness for the heavy duty .

14) chip: Is this ok to mount outside your front door? We have a storm door outside of our main front door. I live in chicago and the weather can get a bit frigid.

Trademark Soundproofing Reply: This product can be used outdoors too.

15) David A: I recently purchased the standard duty auto door bottom product on Amazon- I was hoping to use it to weather seal an exterior door (also has storm door)-but it does not seem to fit that purpose. The air can travel around the edges and over the bottom seal. Does this model improve on air flow?

Trademark Soundproofing Reply:

The smaller the gap the better the seal. Large gaps will cause the seal to extend far out that allows air to go above the seal. If your purpose is for air infiltration we recommend the heavy duty high sound automatic door bottom that has an additional productive rubber layer. For the gaps on the side you would need a "dust plug".

16) Steve M: Can this be cut down to 28.75”?

Trademark Soundproofing Reply: The 322" one can. If you want us to cut it for you just give us a call. Will take about 7-10 days to ship.