Home > Door Seals > Automatic Door Bottoms > Mortised > Pemko #434NB Automatic Door Bottom, Mortised with Double Brush Seal, .75" Drop

Pemko #434NB Automatic Door Bottom, Mortised with Double Brush Seal, .75" Drop

Pemko #434NB Automatic Door Bottom, Mortised with Double Brush Seal, .75" Drop
Mortised Automatic Door Bottom 434NBL with Double Nylon Brush Seal Automatic Door Bottom 434NBL with Double Nylon Brush Seal Applied in Wooden Door with Seal Raised Automatic Door Bottom 434NBL with Double Nylon Brush Seal Applied in Wooden Door with Seal Lowered


To determine size needed, see How to Measure for an Automatic Door Bottom. Note, door bottom can be trimmed up to 2".


Market price: $89.00
save 20%
Price: $71.20
Size Range
Exact Size
Save to wishlist
Made in USA
Shipping See Shipping Tab Below

This heavy duty automatic door bottoms creates a strong seal, preventing fire, smoke, sound, drafts, dust, light moisture and insects from penetrating the gap under doors. Custom cut to size.

How it works: The high quality automatic mechanism consists of an aluminum case which surrounds a moveable drop-bar seal. The drop-bar seal is actuated by a plunger which contacts the door frame jamb as the door is closing, forcing the drop-bar seal down against the floor / threshold. The plunger requires low "Feather Touch" closing force to actuate the drop-bar seal. The seal drops to fill gaps up to 3/4". The mechanism causes the seal to always actuate on the hinge side first, which prevents the seal from skidding along the floor/threshold while the door is being closed (See Application Tab). Door hang-up will not occur!

Seal: This automatic door bottom comes equipped with a double nylon brush seal and aluminum stop. The brush conforms well to surface irregularities and can be used on uneven surfaces. The bristles remain flexible in extreme weather, making it ideal for external doors. The aluminum stop is lowered simultaneously with the brush to prevent it from bending too far back and ensure a proper seal is maintained.

Installation: This automatic door bottom is fully mortised, and will not be seen on the face of the door, making it ideal for high end, luxury doors. Size of casing differs according to length, review product specs before purchasing. Door bottom can be trimmed up to 2".

Door Thickness: Model is compatible with minimum 1-3/4" thick doors.

  • Fire, Smoke, and Air Infiltration rated
  • Aluminum Mill Casing
  • Double nylon brush and aluminum stop>
  • Fills gaps up to 3/4"
  • Fully mortised
  • Can be used with doorway threshold or directly on floor surface

Installation instructions, screws and end plates provided.

To determine size 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 5 year guarantee against defects in material and workmanship.
Click here to view our full Warranty Policy

For a thinner version, see our Mortised Automatic Door Bottom with Nylon and Rubber Seal.

Product Data
Shipping / Returns
  • Ship Time:
    • This product is custom made to your specifications, please allow 10-14 Business Day to ship.
    • Ships via major carriers, such as UPS or FedEx Ground, with tracking information provided.
  • Domestic Shipping Fees- (Hawaii and Alaska not Included):
    • FREE SHIPPING on orders over $200.00 (excludes oversized and freight orders).
    • There will be a flat $19.99 shipping and handling fee on orders under $200.00.
    • Oversized Items: Items 86" and above have an oversize surcharge of $70.00
    • Freight Orders: Items 95" and above require freight shipment and have a shipping charge of $150.00
    • Orders totals above $1,500.00 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 commited to your satisfaction, as a courtesy, we may, at our discretion accept returns with a minimum 25% restock fee.
    • Weatherstripping products will not be considered for returns.
    • Item must be in new, resaleable 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.
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.

Not yet rated. Be the first to Write a Review

Recently Viewed