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With high quality materials and construction, ZERO thresholds are designed to stand up to the demands of heavy traffic applications and those with extreme temperature differentials.

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From increasing energy efficiency to creating a barrier for smoke, sound and light – thresholds serve many important purposes. That’s why it is important to standardize on top quality materials and construction.

Zero thresholds are designed to stand up to the demands of heavy traffic openings and those with extreme temperature differentials. The heavy-gauge material allows you to drill and screw our thresholds directly into concrete without the difficulties common when using lighter commercial materials, such as buckling under heavy loads or loose screws.

Commercial and institutional facilities can benefit from using ZERO for both interior and perimeter applications. Solutions are available for a variety of applications, including:

  • Fire rated doors
  • ADA openings
  • Sound rate assemblies

A variety of types of thresholds are available to accommodate the specific needs of your application. With unique features such as:

  • Energy-efficient thermal-break thresholds – Specially designed to prevent the transfer of outside temperature and frost to the interior side of the door
  • Adjustable-width systems – Features threshold rests that interlock with various size plates. Much easier to trim and fit than conventional, single-size cast-bronze thresholds. Install without exposed screws on the base for better aesthetics and durability
  • Extruded bulb finger (EBF) double sealing system – Designed to ensure an airtight seal even when doors are misaligned because of poor installation or slightly warped. If the door fails to make contact with the bulb in this neoprene gasket, the extra “finger” acts as a supplemental seal to block air flow

ZERO thresholds meet the highest standards in the industry for reliability and performance. See the catalog for specific certification by model number. They include certifications for:

  • Fire Rating
  • Smoke and Draft Control
  • Air Infiltration
  • Sound
  • ADA Accessibility

See catalog for dimensions, drawings, available options and certifications for each part number.

  • Saddle thresholds are the most commonly used because they are beveled equally on both sides and come in varying widths and heights
  • Half-saddle thresholds are raised on one side to ease transition at the sill
  • Offset thresholds are non-symmetrical to address areas where uneven surfaces meet
  • Rabbeted thresholds incorporate a ridged design to seal against the door to provide superior insulation
  • Thermal break thresholds are specially designed to prevent the transfer of outside temperature and frost to the interior side of the door
  • Carpet divider thresholds designed to be used as a divider between two floor finishes
  • Adjustable thresholds Interlocking plates and noses provide flexibility and can be customized to meet the unique requirements of your opening
  • Traction tread adjustable thresholds used to enhance safety with formulated rubber inserts or with an epoxy abrasive (non-slip particles) bonded into the grooves
  • Ramps provide a gradual incline to ease the transition between ground and sill for accessibility
  • Interlocking thresholds allow you to interlock with an angle or hook to prevent water infiltration
  • Adjustable interlocking thresholds allow you to mix and match components to customize a solution
  • Specialized threshold solutions  offer a variety of solution sets are available for various applications from bulkhead systems, roof curb thresholder, wheel chair accessible showers and more

ZERO automatic door bottoms are available in the following finishes:

Aluminum Mill Finish

Clear Anodized Aluminum Finish

BK Aluminum black anodized

Aluminum Black Anodized

D Aluminum dark bronze anodized

Aluminum Dark Bronze Anodized



G Aluminum gold anodized

Aluminum Gold Anodized

B Bronze, architectural mill finish

Aluminum Gold Anodized

B-ORB Oil-rubbed bronze

Aluminum Gold Anodized

  • Non-slip epoxy abrasive (E or EL) 
    Thresholds can be ordered with non-slip epoxy abrasive particles bonded into the grooves, with (EL) or without (E) photoluminescence for exit path markings. The tread provides a coefficient of friction of 1.02 dry and 0.98 wet to comply with ADA, OSHA and most local building code requirements.
  • Full body strength (V3) 
    An aluminum composite filler containing aluminum oxide and silicon carbide. Available as option for most profiles, with no requirement for customized extrusions. Ideal applications include: heavy commercial traffic in supply rooms, manufacturing plants, schools, cafeterias, automobile dealers, hospitals, industrial facilities.
  • No holes (NH) 
    Models supplied standard without mounting holes are noted on the product pages. All other models are supplied standard with mounting holes. Specify NH to order models without mounting holes drilled.


Full Line Zero International Catalog

Installation Instructions

Installation Instructions for Thresholds


Zero Product Solutions E-Brochure

Additional Resources

Intro to Thresholds and Gasketing White Board Video – answers to your door, hardware and code questions from Allegion’s Lori Greene

LEED Certification – Recycled Content ZERO International

CAD Drawings and Data Sheets (Cut Sheets)

Find CAD Drawings and Data Sheets (Cut Sheets) in the Document Library


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