Home > Companies > Lorient Polyproducts Ltd > LAS8003 si Drop Seal

A slimline face-fixed or semi-mortised automatic drop seal. It features a high efficiency mechanism, which lifts the seal clear of the floor as soon as the door is opened by a few millimetres; resulting in lower door operating forces.

Surface mounted application suitable for upgrading existing doors. Requires no power connection. Self-levelling on uneven floors; seal height can be adjusted independently of fixing screws.

Key benefits:

  • Durable flexible elastomeric fin elements are incorporated with the housing to provide acoustic and smoke properties.
  • Tested for acoustic performance with BS EN ISO 10140-2: 2010.
  • Meets the smoke leakage performance requirements of BS 9999 and is used for sealing the threshold of door assemblies against leakage of ambient temperature smoke, as defined in BS 476: Part 31.1: 1983.
  • Suitable for use on timber fire doors for up to 60 minutes under conditions of BS 476: Pt.20/22: 1987 and BS EN 1634-1: 2014 (when face-fixed).
  • Tested for reliability, the seal completed 1 000 000 cycles without failure.

Standard product features


Silicone rubber (grey).


Single swing doors. For use on both right and left handed doors.

Use with:

  • Any perimeter seal.
  • Any threshold plate.


48 mm high (excluding seal in dropped position) x 14 mm wide.

Minimum/ maximum gap size:

1 mm/ 13 mm.

Acoustic performance:

Weighted Sound Reduction Index (Rw): 31 dB.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-75-40/430 Door and window weatherstrips and seals

Product specification

An important note about specifying



Lorient Polyproducts Ltd


+44 (0)1626 834252

Product reference

LAS8003 si Drop Seal


[335 mm]
[435 mm]
[535 mm]
[635 mm]
[735 mm]
[835 mm]
[935 mm]
[1035 mm]
[1135 mm]
[1235 mm]


[Silver anodized aluminiumwith grey end caps and grey silicone rubber gasket]
[Bronze anodized aluminium with black end caps, and black silicone rubber gasket]

Manufacturer details

Endeavour House,
Fairfax Road,
Heathfield Industrial Estate,
Newton Abbot,
Devon, TQ12 6UD
Tel +44 (0)1626 834252
Fax +44 (0)1626 833166
NBS Plus