Lorient LAS4011 100mm Threshold Plate
Lorient LAS4011 100mm Threshold Plate is a low-profile aluminium threshold plate designed to provide a firm, even sealing surface beneath single and double swing doors.
Measuring 100mm wide and 6mm high, the LAS4011 can improve the effectiveness of automatic drop seals and face-fixed door-bottom seals by giving the sealing gasket a smooth and consistent surface against which to close.
Its gently sloping profile is suitable for wheeled traffic, while the durable anodised aluminium finish provides a neat and practical threshold for residential, commercial and public-building doorways.
What is the LAS4011 threshold plate used for?
The LAS4011 is installed on the floor or sill directly beneath a door.
It is commonly used to:
- Provide a firm contact surface beneath an automatic drop seal
- Improve contact beneath a face-fixed door-bottom seal
- Bridge joins between adjoining floor finishes
- Cover grout lines, uneven flooring or small floor transitions
- Support smoke, weather, draught and light containment
- Create a low-profile threshold suitable for wheeled traffic
- Form part of a complete fire, smoke or acoustic door-sealing arrangement
How does the LAS4011 work?
Door-bottom seals work most effectively when their gasket closes against a firm, smooth and continuous surface.
Carpet, grout joints, tiles, timber boards and changes between different floor finishes can prevent a drop seal from making consistent contact across the full width of the doorway.
The LAS4011 creates a durable aluminium contact surface beneath the door. When the door closes, the automatic drop seal or door-bottom gasket rests against the threshold plate rather than the uneven floor beneath it.
This helps reduce open gaps and creates more consistent gasket contact across the doorway.
Does the LAS4011 seal the door by itself?
No. The LAS4011 is a threshold plate and does not contain a flexible sealing gasket.
It should be combined with a suitable automatic drop seal or face-fixed door-bottom seal where containment beneath the door is required.
Lorient states that the LAS4011 can be used with practically any suitable drop or door-bottom seal.
The correct combination will depend on:
- The available gap beneath the door
- The door construction
- The selected drop or door-bottom seal
- The type and condition of the floor
- The required acoustic, smoke, weather or fire performance
- The evidence and certification applying to the complete doorset
What type of containment can it support?
When installed with a suitable threshold seal, the LAS4011 can contribute towards:
- Smoke containment
- Weather protection
- Draught reduction
- Light containment
- More consistent door-bottom sealing
The threshold plate does not provide these functions independently. Its purpose is to give the associated sealing gasket a firm and even surface against which to close.
Can the LAS4011 help with acoustic sealing?
The LAS4011 can support an acoustic door-sealing system by improving contact beneath a suitable automatic drop seal.
The gap beneath a door is often a significant sound-leakage path. A smooth threshold plate can help the door-bottom gasket close this gap more consistently than it would against carpet, grout joints or uneven flooring.
However, the LAS4011 does not have a standalone decibel rating.
Any quoted acoustic performance will apply to a complete tested door assembly and specified sealing arrangement, including:
- The door leaf
- The frame
- The perimeter seals
- The automatic drop or door-bottom seal
- The threshold plate
- Glazing and ironmongery
- The surrounding construction
Fire-test evidence
The current Lorient technical datasheet lists fire-test evidence for the LAS4011 to BS EN 1634-1:2014+A1:2018 in FD30 and FD60 applications.
This does not mean that the threshold plate independently provides 30 or 60 minutes of fire resistance.
Fire performance applies to the tested doorset construction and component arrangement. Where the LAS4011 is being installed on a fire-resisting door, confirm that its use is covered by the door manufacturer’s test evidence, assessment or certification.
Do not substitute threshold components on a certified fire doorset without confirming compatibility.
Why use a threshold plate beneath a drop seal?
An automatic drop seal may not make reliable contact when it closes directly onto a soft or uneven floor.
Common problems include:
- The gasket sinking into carpet
- Small gaps forming over grout joints
- Uneven tiles preventing continuous contact
- Changes in floor finish beneath the doorway
- The seal contacting only the highest parts of the floor
- Floor wear changing the sealing surface over time
The LAS4011 provides a fixed aluminium surface across the doorway, helping the gasket maintain more uniform contact.
Where can the LAS4011 be used?
The LAS4011 is designed for use beneath single and double swing doors.
Suitable applications can include:
- Offices and meeting rooms
- Schools and education buildings
- Hotels and hospitality premises
- Healthcare environments
- Apartment and residential developments
- Commercial buildings
- Retail and leisure premises
- Public buildings
- Internal doorways
- Suitable external doorways
- Fire-resisting doorsets where covered by the relevant evidence
- Doors fitted with automatic drop seals
- Doors fitted with face-fixed door-bottom seals
For exterior installations, suitable sealant should be applied where the threshold plate meets the door stops to help prevent water ingress.
Is the LAS4011 suitable for wheeled traffic?
Yes. Lorient identifies the LAS4011 as suitable for wheeled traffic.
Its profile rises gradually to a maximum height of 6mm, providing a smoother transition than a threshold with abrupt vertical edges.
Project-specific accessibility requirements should still be checked before installation, particularly where the doorway forms part of an accessible route or compliance-led design.
Why choose the 100mm LAS4011?
The LAS4011 provides a 100mm-wide threshold surface and sits between the narrower LAS4010 and wider LAS4012 options.
The 100mm width can be useful where:
- A wider floor transition needs to be covered
- The drop-seal gasket requires a broader contact area
- Different floor finishes meet beneath the doorway
- A low-profile threshold is required without using the wider 125mm or 150mm options
- The threshold forms part of an approved FD30 or FD60 doorset arrangement
The correct width should be selected according to the doorway, floor finish, gasket position and doorset specification.
Key benefits
- 100mm-wide profile — provides a broad and consistent sealing surface beneath the door.
- Only 6mm high — creates a low-profile transition across the doorway.
- Suitable for wheeled traffic — sloping sides allow wheels to travel across the profile more easily.
- Improves gasket contact — provides a firm surface beneath automatic drop and door-bottom seals.
- Fire-test evidence available — listed by Lorient for FD30 and FD60 applications to BS EN 1634-1:2014+A1:2018.
- Aluminium construction — durable and suitable for regularly used doorways.
- Anodised finish — provides a neat and resilient visible surface.
- Suitable for single and double doors — intended for single and double swing-door applications.
- Wide seal compatibility — can be used with practically any suitable drop or door-bottom seal.
- Helps manage uneven flooring — useful where the existing sealing surface is inconsistent.
- Supports multiple containment requirements — contributes towards smoke, weather, draught and light containment when combined with a suitable seal.
- Can be cut to length — standard lengths can be trimmed to suit the doorway.
- Screw or adhesive fixing — can be installed using an appropriate method for the floor substrate.
Helpful advice before buying
Measure the doorway and the clearance beneath the door before ordering.
Lorient states that the LAS4011 requires at least 8mm clearance between the door and floor for effective operation.
The threshold plate itself is 6mm high, so the available clearance must allow the door to pass over the profile without scraping or preventing the door from closing.
Also confirm:
- The required threshold length
- The position of the drop or door-bottom seal
- The width of the required contact surface
- The floor construction and proposed fixing method
- Whether pipes, cables or underfloor heating are present
- The required acoustic, smoke, weather or fire performance
- Whether the proposed arrangement is covered by the doorset certification
The LAS4011 should be treated as one component within a complete door-sealing system. It does not independently soundproof, smoke-seal, weather-seal or fire-rate a doorway.
Lorient LAS4011 100mm Threshold Plate Technical Specifications
Lorient LAS4011 is a low-profile aluminium threshold plate measuring 100mm wide and 6mm high. It provides a firm and even sealing surface beneath single and double swing doors.
Product Specification
| Product Name |
Lorient LAS4011 100mm Threshold Plate |
| Manufacturer |
Lorient |
| Product Reference |
LAS4011 |
| Product Type |
Low-profile aluminium threshold plate |
| Width |
100mm |
| Overall Height |
6mm |
| Material |
Aluminium |
| Standard Finish |
Silver anodised aluminium |
| Alternative Finishes |
Other colour finishes may be available subject to minimum order quantities, non-standard charges and additional lead times |
| Standard Lengths |
1m and 2.1m |
| Special Lengths |
Other lengths may be available to special order |
| Door Types |
Single and double swing doors |
| Installation Position |
Floor or sill-mounted beneath the door |
| Minimum Door-to-Floor Clearance |
8mm |
| Compatible Seals |
Practically any suitable automatic drop seal or face-fixed door-bottom seal |
| Main Function |
Provides a firm and even surface against which a door-bottom gasket can seal |
| Containment Characteristics |
Contributes towards smoke, weather, draught and light containment when fitted with a suitable threshold seal |
| Wheeled Traffic |
Suitable for wheeled traffic |
| Fire-Test Standard |
BS EN 1634-1:2014+A1:2018 |
| Fire-Test Evidence |
LAS4011 listed by Lorient for FD30 and FD60 applications within the relevant tested doorset arrangements |
| Certification Reference |
UL R27972 |
| Fixing Methods |
Screw fixing or suitable construction adhesive, depending on the floor substrate and application |
| Supplied Fixings |
Stainless steel screws and plastic plugs are listed in the current Lorient fitting guide |
| Plate Drilling |
4.5mm fixing holes drilled through the plate and countersunk so the screw heads finish flush |
| Masonry Drilling |
6mm masonry holes where the supplied plastic plugs are suitable for the floor substrate |
| External Installation |
Apply suitable sealant where the plate meets the door stops to help prevent water ingress |
| Standalone Acoustic Rating |
None stated — acoustic performance depends on the complete tested door and sealing system |
| Standalone Smoke Rating |
None stated — smoke containment depends on the associated seal and complete doorset arrangement |
| Standalone Fire Rating |
No — the FD30 and FD60 evidence applies to relevant tested door assemblies and should not be treated as an independent rating for the plate |
| Complete Seal? |
No — the LAS4011 is a threshold plate and requires a suitable drop or door-bottom seal |
Available Length Options
| Option |
Width |
Height |
Typical Use |
| LAS4011 1m |
100mm |
6mm |
Standard single-door openings, subject to the measured doorway width |
| LAS4011 2.1m |
100mm |
6mm |
Wider openings, double doors or cutting into project-specific lengths |
| Special-Order Length |
100mm |
6mm |
Non-standard doorways and project-specific requirements |
Related Threshold Plate Widths
| Product |
Width |
Height |
| LAS4010 |
75mm |
6mm |
| LAS4011 |
100mm |
6mm |
| LAS4012 |
125mm |
6mm |
| LAS4013 |
150mm |
6mm |
Suitable Applications
The LAS4011 can be installed beneath:
- Single swing doors
- Double swing doors
- Doors fitted with automatic drop seals
- Doors fitted with face-fixed bottom seals
- Internal doors
- Suitable external doors
- FD30 and FD60 door assemblies where covered by appropriate evidence
- Doors positioned over carpet
- Doors positioned over tiled flooring
- Doorways between different floor finishes
- Commercial and public-building doors
Threshold-Seal Compatibility
Lorient states that the LAS4011 can be used with practically any suitable drop or door-bottom seal.
The selected seal must be suitable for:
- The door type and construction
- The available gap beneath the door
- The opening direction
- The threshold width and profile
- The required containment performance
- The certification of the complete doorset
Where a particular acoustic, smoke or fire performance is required, use the complete component arrangement stated within the relevant test evidence, assessment or doorset certification.
Minimum Clearance Requirement
The current Lorient fitting guide states that the LAS4011 requires at least 8mm clearance between the door and floor for effective operation.
The plate itself is 6mm high. The additional clearance allows the door to travel over the threshold without rubbing or preventing correct operation.
The door must continue to:
- Open freely
- Close completely
- Engage correctly with the latch
- Operate without scraping across the threshold plate
Measure the clearance at several positions across the doorway and throughout the swing path, as the floor may not be level.
Fire Performance Note
Lorient’s current V5 datasheet lists the LAS4011 with fire-test evidence to BS EN 1634-1:2014+A1:2018 for FD30 and FD60 applications.
This evidence should not be interpreted as an independent 30-minute or 60-minute fire rating for the threshold plate.
The final fire performance depends on the complete tested doorset, including:
- The door leaf and frame
- The threshold and door-bottom seal arrangement
- The perimeter seals
- Door hardware and glazing
- Fixings and installation method
- The direction and configuration of the door
For fire-resisting doors, confirm that the proposed LAS4011 installation is permitted by the door manufacturer’s evidence or certification before beginning work.
Acoustic Performance Note
A threshold plate can support acoustic sealing by giving an automatic drop seal a firm and consistent contact surface.
However, the LAS4011 does not have a standalone Rw or decibel rating.
Final sound reduction will depend on:
- The mass and construction of the door leaf
- The perimeter seals
- The selected automatic drop seal
- The adjustment of the door-bottom gasket
- The frame and surrounding wall
- Glazing and ironmongery
- The quality of installation
Do not specify or advertise the LAS4011 as independently achieving a particular acoustic rating.
Handling and Storage
Store the LAS4011:
- Flat and fully supported
- In a clean and dry location
- Away from moisture and site contamination
- Protected from bending, twisting and impact damage
- With the anodised surface protected from scratching
Take care around freshly cut edges and remove sharp burrs before installation.
How to Install the Lorient LAS4011 100mm Threshold Plate
Lorient LAS4011 100mm Threshold Plate can be installed beneath single or double swing doors using suitable screw fixings or construction adhesive.
The plate should be measured and cut to suit the opening, positioned beneath the selected drop or door-bottom seal and securely fixed without preventing the door from opening, closing or latching correctly.
Always follow the current Lorient fitting guide and check the requirements of the complete doorset before installation.
What You’ll Need
- Lorient LAS4011 threshold plate in the required length
- Supplied stainless steel screws and plastic plugs, where suitable
- Tape measure
- Pencil or suitable marker
- Hand saw or power saw suitable for aluminium
- Power drill
- 4.5mm drill bit
- 6mm masonry drill bit, where appropriate
- Countersink bit
- Suitable construction adhesive, if adhesive fixing
- Suitable external-grade sealant, where required
- File or deburring tool
- Brush or vacuum for removing drilling dust
- Safety glasses
- Suitable gloves
- Hearing protection when using power tools
Before You Start
Inspect the door, frame and floor before cutting or fixing the threshold plate.
Check that:
- The door opens, closes and latches correctly
- There is at least 8mm clearance between the door and floor
- The floor is stable and suitable for the proposed fixing method
- The 100mm profile provides sufficient contact area for the selected seal
- The threshold will align with the automatic drop or door-bottom seal
- There are no pipes, cables or underfloor-heating elements beneath the drilling area
- The plate will not create an unacceptable obstruction
- The proposed installation is compatible with any fire, smoke or acoustic doorset certification
Measure the door clearance at several positions across the doorway and through the complete swing path. The floor may rise at one side or beyond the closed-door position.
Step 1: Measure the Doorway
Remove the threshold plate from its packaging and measure the width of the doorway between the jambs or door stops.
Take the measurement at the exact position where the threshold plate will be installed.
If the plate must fit around the door stops, measure each side carefully. Do not assume that the door frame is square or that both stops are identical.
Step 2: Mark the Threshold Plate
Transfer the doorway measurement onto the LAS4011 using a pencil or suitable marker.
Clearly mark:
- The overall cut length
- Any profiling required around the door stops
- The intended orientation of the plate
- The position beneath the selected door-bottom gasket
Check all measurements before cutting.
Step 3: Cut the Threshold Plate
Cut the aluminium threshold plate using a suitable hand saw or power saw.
Support the plate fully while cutting to prevent vibration, bending or damage to the anodised surface.
Cut slowly and accurately, particularly where the ends must be profiled around the door stops.
After cutting:
- Remove sharp edges and burrs
- Clean away aluminium swarf
- Check that the profile has not been distorted
- Confirm that the visible surface has not been damaged
Step 4: Dry Fit the Threshold Plate
Position the LAS4011 on the door sill or floor in the required location before drilling or applying adhesive.
Check that:
- The plate fits neatly between the jambs or door stops
- It is aligned beneath the closed door
- The selected gasket will contact the correct part of the plate
- The threshold is fully supported by the floor
- The plate does not rock or move
- The door can pass freely over the 6mm-high profile
- The threshold does not interfere with the door swing
Carefully open and close the door while the unsecured plate is held safely in position.
Step 5: Choose the Fixing Method
The Lorient fitting guide provides two installation methods:
- Screw fixing
- Adhesive fixing
Select the fixing method according to the floor construction, site conditions, doorset evidence and project specification.
Screw fixing creates a mechanical connection but requires confirmation that the floor can be drilled safely.
Adhesive fixing avoids drilling through the floor but requires a sound, clean substrate and a construction adhesive compatible with aluminium and the floor material.
Step 6A: Drill the Threshold Plate for Screw Fixing
Mark suitable fixing positions along the threshold plate.
Using a power drill and a 4.5mm drill bit, drill the required fixing holes through the aluminium profile.
Space the holes sufficiently to hold the threshold securely along its complete length.
Countersink each hole so that the screw heads will finish flush with the upper surface of the plate.
Raised screw heads could:
- Interfere with wheeled traffic
- Damage the door-bottom gasket
- Create an uneven sealing surface
- Produce a snagging or trip point
Step 7A: Mark the Floor
Return the threshold plate to its final position.
Using the drilled holes as a guide, mark the fixing-hole centres onto the floor.
Check the position of the plate and all hole centres before removing it for drilling.
Step 8A: Drill the Floor
Remove the threshold plate and drill the marked floor positions.
The Lorient fitting guide specifies a 6mm masonry drill bit where the supplied plastic plugs are suitable for the substrate.
Before drilling, confirm that:
- No pipes, cables or heating elements are present
- The floor material is suitable for the supplied plugs
- The drilling depth is appropriate
- The fixing method is permitted by the doorset specification
- Drilling will not damage the floor or damp-proofing system
Use alternative substrate-specific fixings where the supplied plugs are not suitable.
Remove all drilling dust and debris before inserting the plugs.
Step 9A: Secure the Plate with Screws
Insert the supplied plastic plugs where appropriate and place the LAS4011 back into position.
Install the supplied screws and tighten them evenly along the threshold.
Check that every screw head finishes flush within its countersunk hole.
Do not overtighten the fixings, as this could distort the aluminium profile or pull it unevenly against the floor.
The finished plate should be:
- Secure
- Fully supported
- Flat against the floor
- Free from movement
- Free from twisting or distortion
Step 6B: Prepare for Adhesive Fixing
Where adhesive fixing is appropriate, prepare the floor and underside of the threshold plate in accordance with the adhesive manufacturer’s instructions.
The contact surfaces should normally be:
- Clean
- Dry
- Stable
- Free from dust
- Free from grease, wax and loose material
Do not bond the threshold plate onto loose carpet, unstable flooring or contaminated surfaces.
For fire-resisting doorsets, confirm that adhesive fixing is permitted by the relevant installation evidence before proceeding.
Step 7B: Apply the Adhesive
Apply a suitable construction adhesive to the back of the LAS4011.
Use enough adhesive to support the threshold securely without applying so much that it spreads onto the visible surface or beyond the edges.
Place the plate carefully into its final position and press it firmly against the floor.
Check the alignment immediately, as repositioning may become difficult once the adhesive begins to grip.
Step 8B: Support the Plate During Curing
Keep the threshold plate firmly in position while the adhesive cures.
Use suitable weights or temporary restraint where permitted by the adhesive manufacturer, taking care not to bend or mark the aluminium.
Do not permit normal foot or wheeled traffic over the plate until the adhesive has achieved the required curing strength.
Curing time will depend on:
- The selected adhesive
- The floor material
- Temperature
- Humidity
- The amount of adhesive applied
Step 10: Seal External Junctions
For exterior applications, Lorient states that sealant should be applied where the threshold plate meets the door stops to help prevent water ingress.
Use a suitable external-grade sealant compatible with:
- The aluminium threshold plate
- The frame or door-stop material
- The floor or sill
- The anticipated weather exposure
Apply the sealant neatly without blocking any required drainage paths.
Step 11: Adjust the Drop or Door-Bottom Seal
Once the threshold plate is secure, adjust the associated automatic drop seal or door-bottom seal according to its separate fitting instructions.
The gasket should contact the LAS4011 consistently across the full width of the doorway.
Check for:
- Continuous gasket contact
- Open gaps at either end
- Insufficient contact in the centre
- Excessive gasket compression
- Uneven drop-seal operation
- Interference with the movement of the door
Do not over-adjust the seal. Excessive compression can increase operating forces, damage the gasket and place unnecessary strain on the drop-seal mechanism.
Step 12: Complete the Final Door Check
Open and close the door several times.
Confirm that:
- The door opens freely
- The door passes over the threshold without scraping
- The door closes completely
- The latch engages correctly
- The threshold remains securely fixed
- All screw heads are flush
- The plate does not flex or move
- The drop or door-bottom seal operates correctly
- The gasket contacts the threshold consistently
- No sharp edges or burrs remain exposed
The installation must not impede the opening or closing of the door.
Installation Tips
- Confirm that there is at least 8mm clearance beneath the door.
- Measure the clearance at multiple points across the doorway.
- Dry fit the LAS4011 before drilling or applying adhesive.
- Check that the 100mm width aligns with the door-bottom gasket.
- Use a saw blade suitable for cutting aluminium.
- Protect the anodised finish while cutting and drilling.
- Remove all burrs from cut edges and drilled holes.
- Countersink fixing holes so the screw heads finish flush.
- Check for concealed services and underfloor heating before drilling.
- Use fixings suitable for the actual floor substrate.
- Do not install the plate over loose or unstable flooring.
- Use suitable sealant at door-stop junctions in exterior applications.
- Adjust the associated door-bottom seal only after the threshold is secure.
- Check that the door continues to close and latch correctly.
- For fire doorsets, follow the tested or certified installation arrangement.
Maintenance Advice
Inspect the LAS4011 periodically as part of the door’s normal maintenance programme.
Check for:
- Loose or raised fixing screws
- Movement of the threshold plate
- Damage or distortion to the aluminium profile
- Sharp or damaged edges
- Failed or separated adhesive
- Failed sealant at exterior junctions
- Dirt affecting gasket contact
- Changes in the door’s floor clearance
- Incorrect operation of the associated drop seal
- Failure of the door to close or latch correctly
Clean the plate with a soft cloth and a suitable mild cleaning product.
Avoid abrasive pads, wire brushes and aggressive chemicals that could damage the anodised finish.
Remove dirt and debris from the sealing surface so the door-bottom gasket can continue to make consistent contact.
Important Performance Note
The LAS4011 is a supporting threshold component. It does not provide complete acoustic, smoke, weather, draught, light or fire containment by itself.
Final performance depends on:
- The associated automatic drop or door-bottom seal
- The perimeter seals
- The door and frame construction
- The gasket adjustment
- The surrounding construction
- The installation quality
Where the door forms part of a certified acoustic, smoke or fire-resisting assembly, install only the threshold and seal arrangement permitted by the relevant test evidence, assessment or doorset certification.