Lorient LAS8005 si Drop Seal is a slimline, mortised automatic door-bottom seal designed to reduce sound, smoke, draught and light transfer through the gap beneath a door.
The seal is recessed into a machined groove along the bottom edge of the door, creating a discreet installation with the main aluminium mechanism concealed within the door leaf.
Its mechanical actuator automatically lowers the silicone gasket when the door closes and retracts it when the door opens. No electrical power connection is required.
The LAS8005 si is installed within the bottom edge of a door to seal the gap between the door leaf and the floor, sill or threshold plate.
An untreated gap beneath a door can allow sound, smoke, draughts and light to pass between adjoining spaces. The LAS8005 si closes this gap automatically when the door shuts and lifts away from the floor when the door opens.
It is commonly used for:
The LAS8005 si contains a spring-loaded mechanical drop-seal system operated by an actuator button at the hinge side of the door.
As the door closes, the actuator button meets the door frame or striker. This activates the internal mechanism and lowers the flexible silicone gasket onto the sill, floor or threshold plate.
When the door begins to open, pressure is released from the actuator and the gasket lifts clear of the floor after only a few millimetres of movement.
This helps reduce:
The LAS8005 si is a mortised automatic drop seal.
It is installed into a groove machined along the bottom edge of the door. Lorient’s current fitting guide specifies a groove measuring:
The seal is then secured through its pre-drilled and countersunk fixing flanges.
Mortised installation creates a discreet finish and is particularly suitable for new doors, workshop preparation and doors that can safely accommodate the required groove.
The LAS8005 si has been acoustically tested to BS EN ISO 10140-2:2010, with Lorient stating performance of up to Rw 33dB within the relevant tested door assembly.
The quoted figure applies to the complete tested doorset and sealing arrangement. It is not an independent 33dB rating for the drop seal itself.
Final acoustic performance will depend on:
For effective acoustic containment, suitable seals should also be installed around the head and jambs of the door.
The LAS8005 si has smoke-test evidence to:
The seal can contribute towards smoke containment by closing the otherwise open gap beneath the door.
It should be combined with suitable smoke seals around the head and jambs. Final smoke performance depends on the complete doorset construction, associated seals and installation quality.
The LAS8005 si has fire-test evidence to BS 476-20/22:1987 and is suitable for use on appropriate fire-rated timber-based door assemblies.
Lorient states that a cladding kit must be used for the FD60 variant.
This does not mean that the drop seal independently provides 60 minutes of fire resistance. The fire performance applies only when it is installed as part of a suitable tested or assessed doorset arrangement.
Before installing the LAS8005 si on a fire-resisting door, confirm:
The LAS8005 si is designed to self-level across slightly uneven floor or threshold surfaces.
The gasket lowers progressively as the door reaches its closed position, helping it make contact across the width of the opening.
The amount of gasket movement can be adjusted independently of the fixing screws by turning the actuator button.
This allows the seal to be adjusted without removing or repositioning the aluminium housing.
Lorient states a published operating range of:
The actuator should be adjusted so the silicone gasket touches the sill or threshold during the final closing movement of the door.
The gasket should make continuous contact without being compressed more than necessary.
The LAS8005 si is suitable for:
The actuator button must be positioned at the hinge side so that it meets the frame or striker as the door closes.
Suitable applications can include:
Yes. Lorient states that the LAS8005 si can be used with any suitable threshold plate.
A threshold plate provides a firm, smooth and consistent surface against which the silicone gasket can close.
This can be particularly useful where the existing floor is:
Lorient illustrates the LAS8005 si with the LAS4002 40mm threshold plate, although another suitable threshold plate may be used where permitted by the project specification and doorset evidence.
Yes. Lorient recommends using the LAS8005 si with a suitable perimeter seal.
The drop seal treats the threshold gap, while perimeter seals treat the:
Using both creates a more continuous sealing arrangement around the door leaf.
Measure the door width and confirm that the door can safely accommodate a groove measuring 14mm wide and 35mm deep.
The LAS8005 si is supplied in fixed length increments and may only be shortened within Lorient’s stated cut-back limits.
Also check:
Drop seals shorter than 635mm use a single-spring mechanism and may not operate correctly until they are fully fitted and activated by the closing door.
Lorient LAS8005 si is a slimline, mortised automatic drop seal with a self-levelling silicone gasket. It is installed within a machined groove along the bottom edge of the door.
| Product Name | Lorient LAS8005 si Drop Seal |
| Manufacturer | Lorient |
| Product Reference | LAS8005 si |
| Product Type | Automatic mortised door-bottom drop seal |
| Installation Type | Mortised and screw-fixed through the flanges |
| Application | Sealing the threshold gap beneath single and double swing doors |
| Operating Method | Mechanical actuator lowers the gasket as the door closes and retracts it when the door opens |
| Power Requirement | None — mechanically operated |
| Required Groove Width | 14mm |
| Required Groove Depth | 35mm |
| Approximate Flange Width | 35mm overall according to the current profile drawing |
| Published Minimum Gap | 1mm |
| Published Maximum Drop | 13mm |
| Seal Material | Grey silicone rubber as standard |
| Carrier Material | Aluminium |
| Self-Levelling | Yes — designed to adjust across slightly uneven floor or threshold surfaces |
| Adjustment | Actuator-button adjustment independent of the fixing screws |
| Adjustment Direction | Clockwise reduces movement; anti-clockwise increases movement |
| Door Types | Single swing, single-leaf and double-leaf doors |
| Door Handing | Suitable for right- and left-handed doors |
| Actuator Position | Hinge side of the door |
| Door Construction | Suitable timber-based door assemblies; may be fitted into aluminium doors by door fabricators |
| Use With | Any suitable perimeter seal and threshold plate |
| Acoustic Test Standard | BS EN ISO 10140-2:2010 |
| Acoustic Test Evidence | Up to Rw 33dB within the relevant tested door assembly |
| Smoke Test Standards | BS EN 1634-3:2004 at ambient temperature and BS 476-31.1:1983 |
| Fire Test Standard | BS 476-20/22:1987 |
| FD60 Requirement | The appropriate cladding kit must be used for the FD60 variant |
| Durability | Tested to 100,000 operating cycles |
| Containment Characteristics | Contributes towards sound, smoke, draught and light containment |
| Wheeled Traffic | Suitable; the gasket retracts when the door opens |
| Standard Finish | Silver anodised aluminium with grey end caps and grey silicone rubber gasket |
| Non-Standard Finish | Black end caps and black silicone gasket may be available subject to charges, minimum order quantities and additional lead times |
| Fixing Method | Screw-fixed through pre-drilled and countersunk flange holes |
| Fixing Screws | Supplied |
| End Caps | Two end caps supplied |
| Striker Button | One striker button supplied |
| Certifire Reference | CF5179 |
| UL Certification Reference | R27972 |
| Positive-Pressure Classification | 5DL3 classification shown in the current fitting guide |
| Short-Length Mechanism | Lengths below 635mm use a single spring and operate correctly only when fully fitted and in use |
| Standalone Acoustic Rating? | No — Rw 33dB applies to a relevant tested complete door assembly |
| Standalone Fire Rating? | No — fire performance depends on the complete tested or assessed doorset arrangement |
| Supplied Length | Minimum Permitted Cut Length |
|---|---|
| 335mm | 255mm |
| 435mm | 335mm |
| 535mm | 435mm |
| 635mm | 535mm |
| 735mm | 635mm |
| 835mm | 735mm |
| 935mm | 835mm |
| 1035mm | 935mm |
| 1135mm | 1035mm |
| 1235mm | 1135mm |
The LAS8005 si must only be shortened from the end opposite the actuator button.
Do not cut the seal below the minimum permitted length stated for the supplied size. Cutting the product too short can interfere with the internal spring and operating mechanism.
When shortening the seal:
The LAS8005 si can be used on:
Lorient states acoustic test evidence of up to Rw 33dB in accordance with BS EN ISO 10140-2:2010.
This figure applies to a complete tested door assembly and does not represent the independent sound reduction of the LAS8005 si.
Final performance will depend on:
The current Lorient product information lists smoke-test evidence to:
The LAS8005 si should be used as part of a complete smoke-sealing arrangement with suitable seals around the head and jambs.
Final smoke performance depends on the complete door construction and tested component arrangement.
The current Lorient datasheet lists fire-test evidence to BS 476-20/22:1987.
Lorient also states that:
These references should not be interpreted as an independent fire-resistance period for the drop seal.
For a fire-resisting door:
The LAS8005 si can operate directly against a suitable smooth floor or sill.
A threshold plate can provide more consistent gasket contact where the existing surface is:
The selected threshold plate must be compatible with the available clearance, the 13mm maximum drop and the applicable doorset evidence.
Store the LAS8005 si:
Do not allow dust, timber chips or metal swarf to enter the internal mechanism.
Lorient LAS8005 si Drop Seal is mortised into a groove machined along the bottom edge of the door.
The seal should be positioned on the centre line of the door, with the actuator button located at the hinge side.
It must only be shortened from the end opposite the actuator button and must not be cut below Lorient’s stated minimum cut-back length.
Always check the current Lorient fitting guide and the evidence for the complete doorset before installation.
Inspect the door, frame and threshold before machining or fitting the seal.
Check that:
Do not machine a fire-rated, hollow, glazed or specialist door until the proposed groove has been checked against the door manufacturer’s evidence.
Remove the LAS8005 si from its packaging and identify:
The current cut-back limits are:
Do not cut the seal below the minimum length stated for the supplied size.
Remove the door from its hinges.
Lay the door securely on its side and restrain it so that it cannot move while being measured, routed or drilled.
Support the door across its full length to avoid:
If the bottom edge is already correctly grooved to suit the LAS8005 si, clean and inspect the groove before continuing.
Measure and mark the seal position along the bottom edge of the door.
For optimum operation, Lorient instructs that the seal should be positioned on the centre line of the door.
Mark the complete routing area clearly.
Check that the proposed groove:
Fit a suitable long-series cutter to the router and set the guide.
Machine a continuous groove along the bottom of the door measuring:
Route the groove in controlled passes rather than attempting to remove the full depth in one pass.
Keep the router stable and maintain a straight, consistent mortise.
Use suitable extraction to control timber dust and chips.
Remove all timber chips, dust and debris from the groove.
Measure the finished mortise to confirm that it is:
Dry fit the LAS8005 si to confirm that the housing sits correctly and the fixing flanges rest against the bottom edge of the door.
Measure the width of the door at the bottom edge.
Subtract the combined thickness of the end plates before marking the aluminium seal for cutting.
The finished drop seal should fit neatly across the door without the end caps binding against the frame or door stops.
Check the required finished length against the minimum cut-back size for the supplied seal.
At the end opposite the actuator button, carefully pull the silicone gasket away from the section that needs to be cut.
Move enough gasket away from the cutting position to prevent the saw from damaging it.
Do not:
Using a suitable power saw or hacksaw, cut the aluminium sections to the marked finished length.
Support the seal securely while cutting to prevent vibration or distortion.
After cutting:
Do not leave metal swarf inside the operating mechanism.
Push the silicone gasket back into its normal position.
Allow it to sit naturally without stretching or bunching.
Trim the gasket to the finished length using a sharp knife, scissors or suitable snips.
The gasket should finish neatly inside the end-cap arrangement without being pulled tight or left excessively long.
Place the LAS8005 si into the machined groove.
Make sure the actuator button is positioned at the hinge side of the door.
Check that:
Use the pre-drilled and countersunk holes in the fixing flanges to mark the pilot-hole positions on the bottom edge of the door.
Remove or hold the seal aside and drill suitable pilot holes using the 2.5mm drill bit listed in Lorient’s fitting guide.
The pilot-hole depth must suit:
Do not drill into concealed door hardware, glazing channels or structural components.
Return the LAS8005 si to the groove and secure it using the supplied screws.
Tighten the screws evenly through the fixing flanges.
Do not overtighten the fixings, as this could:
Check that the housing remains straight and firmly seated within the mortise.
Fit the two supplied end caps to the ends of the seal.
Make sure each cap is fully seated and does not interfere with:
The end caps should finish neatly against the door edges.
Carefully return the door to its frame and refit it to the hinges.
Confirm that:
For timber frames, fit the supplied striker button to the frame opposite the actuator button.
Align the striker so that the actuator meets it directly as the door closes.
The striker should:
Open and close the door while observing the silicone gasket.
The gasket should:
Drop seals below 635mm use a single spring and may only operate correctly once fully installed and activated by the closing door.
Adjust the gasket movement by turning the actuator button:
Make small adjustments and test the door after each change.
For optimum results, Lorient states that the silicone gasket should touch the sill during the final closing moment of the door.
Avoid excessive drop or compression.
Too much movement can:
Close the door and inspect the gasket across its complete width.
Check that:
Where the floor is too uneven or soft, install a suitable threshold plate to provide a smoother sealing surface.
Open and close the door several times.
Confirm that:
Lorient recommends using the LAS8005 si with a suitable perimeter seal.
The perimeter seal treats the gaps around the:
The LAS8005 si then closes the remaining gap beneath the door.
For tested acoustic, smoke or fire performance, use the complete component arrangement stated in the applicable doorset evidence.
A suitable threshold plate can provide a firm and level contact surface beneath the drop seal.
This is useful where the existing floor is:
The threshold plate must not reduce the available clearance below the operating requirements of the drop seal.
After installing the threshold plate, readjust the actuator so the gasket makes light and consistent contact during the final closing movement.
Inspect and test the LAS8005 si periodically as part of the door’s normal maintenance programme.
Check for:
Clean the gasket and threshold using a soft cloth and a suitable mild cleaning product.
Avoid abrasive tools, aggressive chemicals and unapproved lubricants.
Readjust the actuator if the door settles, the hinges move or the threshold level changes.
Correct machining, cutting, positioning and adjustment are essential to the performance of the LAS8005 si.
The gasket should make continuous contact with the sill or threshold during the final closing movement, but it must not be adjusted so heavily that it prevents the door from operating correctly.
Final acoustic, smoke and fire performance depends on the complete door assembly, including:
For certified acoustic, smoke or fire-resisting doorsets, follow the applicable test evidence, assessment and door manufacturer’s instructions in addition to this general installation guidance.
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