Automatic Door Bottom

The 36″ Automatic Door Bottom offers positive lock to smooth floors. Rubber sealing bar is automatically deployed a maximum drop of 3/4″ when door is closed. Can be trimmed up to 2″ for narrower door. The design combines low operating force with an adjustable sealing bar. We recommend you use in conjunction with our Door Jamb Seal.

SKU: 365AA Category:

ZERO designs and builds automatic door bottoms to last. Our automatic door bottoms have been tested through 5 million cycles. You can specify with confidence.
The advanced technology common to all ZERO models utilizes a concealed flat spring mechanism, which activates when the door is closed, lowering a neoprene seal insert against the floor or saddle. A protruding, hinge-side “plunger” is compressed by the frame as the door closes to activate the spring. The seal then drops in a scissors-like motion from the hinge side, adjusting to the floor from a pivoting point. This motion ensures a smooth drop without drag for a tight, secure seal against the saddle or floor. The seal retracts automatically as the door is opened.

Optimizing the acoustical performance of a door seal kit involves the combination of adjustable gasketing and compression seals. To be effective at blocking sound, the seal around the door at the head, vertical sides and sill must be complete, uninterrupted and airtight. If all sides and the space at the door bottom are not sealed properly, the gasketing will provide little or no sound control value. The Doorseal kit provides everything you will need to effectively seal off the door. Including jam seals for the top and vertical sides of the door and an automatic door bottom and threshold to effectively seal off the bottom off the door.

Our acoustical head and jamb seals are secured directly to the doorstop. This acoustical seal features our unique compress-o-matic design with a sound-absorbing neoprene bulb that compresses to form a tight seal as the door is closed. They include adjusting screws for field correction of irregular clearances that might otherwise compromise the sound performance. These acoustical jambs are listed for both wood and metal doors.

Our automatic door bottoms utilize a flat spring mechanism, which activates when the door is closed, lowering a neoprene seal insert against the floor or saddle. The frame compresses a protruding, hinge-side “plunger” as the door closes to activate the spring. The seal then drops in a scissors like motion from the hinge side, adjusting to the floor from a pivoting point. This motion ensures a smooth drop without drag for a tight seal, even on an uneven floor. As the neoprene seal compresses, it forms a tight, secure seal against the saddle or floor. The seal reacts automatically as the door is opened

This acoustical door threshold, commonly referred to as a saddle, features a neoprene bulb fitted with a protruding rubber finger to help correct any misalignment in the door as it is closed.

Features

Features:

  • Class 1 fire rated
  • Standard aluminum finish
  • Options for a dark bronze anodized or simulated bronze anodized finishes are available
  • Door seal kit is for standard 3’x7′ doors, however kits are available for oversized, undersized and double doors

Specifications

Automatic Door Bottom Specification

  • Maximum drop 1″.
  • Reversible — same unit used for left or right-handed door.
  • Rated for up to “A” label (3hrs.)
  • Supplied with solid neoprene extrusion, self-extinguishing, under MIL R6855 Type II Class 40 oil resistant.
  • All rated for 5 million cycles.
  • Jamb seals #770
  • Automatic door bottom #367A
  • Threshold #564A or #565A
  • STC rating 52

Testing

UL Classification

Meets UL10B, UL10C and UBC 7-2 (1997) Category J 17L5. Positive Pressure Tested Gasket Material for Fire Doors. Intended for Application to/with listed steel frames and /or classified steel covered composite, hollow metal type fire doors rated up to 3 hours, wood and plastic covered composite type fire doors rated up to 1 1/2 hours , and wood core type fire doors rated up to 20 minutes.

Measuring

Measuring or an Automatic Door Bottom

  1. Cut the door bottom to the length as follows.
  2. Determine distance between door stops. Door bottom should be cut 3/32” shorter than this distance.
  3. There is a 1/2” block in part when shipped opposite the activating screws. This holds sealing bar in the lowered position as when the “door is closed”.
  4. Note: Only the end opposite the activating screw may be trimmed.
  5. Turn adjusting screws on top of door bottom so the mechanism is withdrawn into the case as far as possible.
  6. Slide neoprene in sealing bar towards the activating screw and cut the door bottom. It is best to apply pressure against the neoprene sealing bar and the 1/2” block to prevent vibration of the mechanism while cutting. Trim the neoprene to about 1/4” longer than sealing bar at each end.

Installing

Installing an Automatic Door Bottom Seal on door

  1. To develop full sealing pressure it is necessary for the sealing bar to drop a full 1/2”. These instructions must be carefully followed to ensure this drop is obtained.
  2. With 1/2” block still installed in door bottom, close door and lay door bottom in place on floor. Slide activating screw against stop and transfer attachment screw holes.
  3. Remove door bottom, drill holes, remove 1/2” block and attach part to door.
  4. Open and close door a few times and then adjust door bottom with adjustment screws on the top of case for even pressure across width of door bottom.
  5. Operate the door several times to ensure that the gasketing material is properly adjusted so as not to inhibit the door from self-closing and latching properly.