Zero #321, Automatic Door Bottom, Surface Mounted Aluminum with Neoprene Seal, .5" Drop

Zero #321, Automatic Door Bottom, Surface Mounted Aluminum with Neoprene Seal, .5" Drop
Zero International
Read 3 reviews

This Zero International #321, regular duty, surface mounted automatic door bottom is fitted with a high quality, extruded neoprene seal insert, which effectively prevents the infiltration of light, sound, drafts, dirt, and smoke. Made with a high quality mechanism that has been successfully tested through 5 million cycles! Available in two anodized finishes. Length is custom cut to size.

Sizing: To determine length needed, see How to Measure for an Automatic Door Bottom.

How to Order: Selecting Finish and Exact Size required will determine your total price. Note, product is priced per range with 18.25"-36" being the lowest priced range.

See tabs below for additional information
    • SKU
      ZR321AA|18
      • 19% off
      Market price: $110.32 save $20.96
    • Starting price: Price: $89.36 per item
     

    This automatic door bottom has a unique sloped profile which prevents water and dirt from seeping behind the casing and will extend the life of the door and product.

    Fitted with a high quality, durable, neoprene seal. Additional rubber in the interior of the casing contributes to the smooth operation of this model.

    Optimum clearance between door bottom unit and­ floor or sill is .375”. Seal has a maximum effective drop of .5".

    Handing: Product is handed. It is shipped at factory default handing and can be easily reversed in the field.

    Installation: Surface mounted application for easy installation. Installation instructions and sheet metal screws are provided for installation. Screws are colored to coordinate with casing.

    Sizing: To determine length needed, see How to Measure for an Automatic Door Bottom.

    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.

    This product has a 1 year guarantee against defects in material and workmanship.
    Click to view our Full Warranty Policy.

    For a fully mortised option, see our Zero International #323 Mortised Aluminum and Neoprene Automatic Door Bottom.

      • SKU
        ZR321AA|18
    • QuickShip
      No
    • Manufacturer
      Zero International
    • MPN
      321
    • Product Design
      • Mounting Type
        Surface Mounted
      • Door Type
        Wooden Door, Hollow Metal Door
    • Dimensions
      • Casing Dimensions
        The aluminum casing measures .595" wide, with a full height of 2". Made of .062" thick aluminum.
      • Length
        Custom Cut to Size
      • Drop Size
        Up to .5" Drop
    • Installation
      • Handing
        Right Handed, Left Handed
      • Installation Screws
        Installation Screws Provided
      • Sizing
        To determine sizing required see 'How to Size an Automatic Door Bottom'
    • Special Features
      • Compatible Insert Replacement
        #320N Neoprene Insert
    • Finishes
      • Finish
        Clear Anodized Aluminum (US28), Dark Bronze Anodized Aluminum (313)
    • Compliance Details
      • Compliance Details
        Fire Rated, BHMA Certified
      • ANSI Designation
        R3B3341
      • Warranty
        1 Year Limited Warranty

    Automatic Door Bottoms utilize a concealed flat spring mechanism and plunger. When the door is closed, a brass plunger is compressed to automatically lower the seal, starting from the hinge side first. This motion ensures a smooth usage even on an uneven surface and prevents drag. The seal is automatically raised upon opening. These automatic door bottoms have been successfully tested through 5 million cycles!

    See also About Automatic Door Bottoms.

    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. 

    STEP 1: SIZING YOUR DOOR BOTTOM

    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 1You can trim from the edge up to one inch of the screw in the side wall of the ADB.
     

    STEP 2: PREP FOR ATTACHING AUTOMATIC DOOR BOTTOM

    How to Install an Automatic Door Bottom- Figure 3Surface Mounted and Semi-Mortised models need to be applied to the push side of the door only (the side with the door stops). 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.

    STEP 3: ATTACHING THE AUTOMATIC DOOR BOTTOM

    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. 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.
     

    STEP 4: TESTING YOUR AUTOMATIC DOOR BOTTOM

    How to Install an Automatic Door Bottom- Figure 5Now 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.

    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.

     

    compliance details for z321


    SHIPPING / PROCESSING TIME:

    This product ships directly from the manufacturer. 
    This product ships directly from the manufacturer. 
    Please allow 2 - 3 weeks to ship



    • Domestic Shipping Fees- (Hawaii and Alaska not Included):
      • FREE SHIPPING on orders over $300.00 (excludes oversized and freight orders). 
      • There will be a flat $19.99 shipping and handling fee on orders under $300.00.
      • Oversize: Orders containing items sized 50" - 95" have an oversize surcharge of $49.99.
      • Freight Items: Orders containing items sized 96" - 108" have an oversize surcharge of $199.99.
      • Oversize Freight Items: Orders containing items sized 109" and above have an oversize surcharge of $299.99.
      • Orders totals above $2,000.00 will ship free, regardless of size.
         
    • Alaska and Hawaii, Canada, and International Shipping:
    • Returns:
      • This product is custom made and is not returnable.
      • We are committed to your satisfaction, as a courtesy, we may, at our discretion accept returns with a minimum 30% restock fee.
      • CLAIMS FOR SHORTAGE OR DAMAGE IN TRANSIT: All claims must be made within Seven (7) days of receipt of goods.
      • Weatherstripping products will not be considered for returns.
      • Item must be in new, re-saleable condition.
      • 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. A return address will be provided with RMA#.
      • 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.
    3.7
    3 Reviews
    100% would recommend this to a friend

    Ratings Distribution

    5 Stars 33.33 1
    4 Stars 33.33 1
    3 Stars 0 0
    2 Stars 33.33 1
    1 Star 0 0

    Pros

    • 1 Good Design
    • 1 Quality Materials

    Reviewed by 3 customers

    2

    Not for a garage door with a slab slope

    Comments about Zero #321, Automatic Door Bottom, Surface Mounted Aluminum with Neoprene Seal, .5" Drop

    This might work for a door with a level threshold but it doesn't work for a side garage door with a normal slab slope towards the front of the garage. There is about ¼" gap difference from one side of the door to the other but the automatic door bottom doesn't compensate for this as expected. The "high" side seal touches but the "low" side still has a gap even thought I adjusted it for more drop.

    By Scott
    Verified Buyer
    5

    Tropical Bugs Meet Their Match

    Comments about Zero #321, Automatic Door Bottom, Surface Mounted Aluminum with Neoprene Seal, .5" Drop

    I bought these for our tropical home in an effort to keep crawling bugs out at night. It's amazing what can squeeze under a conventional weatherstrip! Anyway, problem solved.

    By Jon
    Verified Buyer
    4

    Best product for my application

    Comments about Zero #321, Automatic Door Bottom, Surface Mounted Aluminum with Neoprene Seal, .5" Drop

    I purchased 3 of these automatic bottoms for use on an exterior entrance consisting of a 42" main door and 2- 24" doors for ventilation on either side. I especially wanted the integral weather hood as snow would pile against these doors. I would have preferred silicone seals for temperature and wear when frozen, but hopefully neoprene will be durable. The online order form does not allow one to specify handing, but an email to TMHardware said that could be handled in the field. There were no instructions on how to do this, and it took me some time to realize just how the hidden spring mechanism works so that I could end-for-end it. These bottoms are cut to length and drilled in the factory to order specifications, but I had to drill an extra mounting hole in the 42" bottom near the end for proper attachment. The instructions do not tell one at what height to mount the bottom. All pictures indicate that the bottom is to be mounted with the metal portion of the body flush with the bottom of the door. This is great for interior doors with no threshholds, but for an exterior door with a stop threshhold and weatherstripping, the bottom of the door is below the threshhold. I mounted it 1/8" above the threshhold and it now seals well without exposing the aluminum track that holds the neoprene seal. I discovered that when the door stops have weatherstripping, only half of the adjusting screw hits the metal stop. I hope that this will not become a problem. To apply the ends to make the bottom look finished, one must create threads with a philips-head screw in an aluminum extrusion. An impact driver rounded out the philips, so I had to use locking pliers on the screw head to complete the threads.

    By Carl
    Verified Buyer
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