Pemko 4131 Auto Door Bottom
Pemko 4131 Auto Door Bottom Seal Profiles End Plates

Pemko Automatic Door Bottom #4131 - Surface Mount or Semi-Mortised Style

CODE: PK4131


Product Description:

Pemko Automatic Door Bottom #4131 - Surface Mount or Semi-Mortised Style

Catalog #PK4131

Pemko Surface Mount AUtomatic Door Bottom Model 4131

  • Suitable for wooden or metal doors, this surface-mounted door bottom is screwed to the face of the door. Alternatively, it can be semi-mortised into the face of a wooden door so that it is flush with the door face.

  • Select 32", 36" or 48" length. May be trimmed down in length by as much as 2" without interfering with drop-bar mechanism.

  • Or you may specify Custom length up to 36" or Custom length 36" to 48", and then specify in the Notes section of your order the exact length you want (Notes are on the last payment page). We will have Pemko custom cut the door bottom to that measurement and drop ship it directly to you (a $7.50 surcharge is included for these custom cuts).

  • Non-handed and reversible. Disassembly is not required to change handing. Simply flip the door bottom and you have reversed the hand.

  • Seals up to a 3/4" gap under the door.

  • Black nylon end plates are provided to hide both ends, protect the mechanism and give a clean appearance. See drawing at bottom of page.

  • This aluminum automatic door bottom is available in two finishes:
    • Clear anodized aluminum
    • Dark bronze anodized aluminum

  • Three types of seal are available for this door bottom. All are designed to conform well to the floor/threshold surface. See additional photos at bottom of page.
    • PemkoPrene (PK). Pemko's proprietary thermo-plastic elastomer, which has a hollow cross-section and is very compressible.
    • Soft, closed-cell sponge neoprene (R). Remains pliable down to -70 degrees F.
    • Sponge silicone (S). Pemko's newest and most expensive option.

  • Measured, enlarged diagram of #4131 Pemko automatic door bottom with the sponge neoprene seal:

  • See the Automatic Door Bottoms product category for more detailed information about these Pemko door bottoms.


  • Be sure to specify length as well as finish and seal type in the Product Options area at top of page. If you are ordering a custom length, specify this length (in inches) in the Notes section of your order (on the last payment page).

  • Allow two to three weeks for shipment of 48" door bottoms. Shipment may be quicker, but we do not stock 48" door bottoms in every finish and seal option.

  • This automatic door bottom can be trimmed down in length by as much as 2".

  • We can get this door bottom in any length from 18" to 72". Send us a message or call us at 800-260-5625 for pricing and lead time for door bottoms longer than 48".

  • NOTE: We recommend that these automatic door bottoms be installed by a carpenter or contractor or other person with experience hanging doors. Installation may involve rehanging the door and cutting it to height.  For the semi-mortise installation, it also involves cutting a rabbet in the bottom face of the door with a router or circular saw. Pemko does provide installation instructions.