Norsound NOR625 Threshold Plate – 75 × 4.9mm
Norsound NOR625 Threshold Plate – 75 × 4.9mm is a low-profile aluminium plate designed for installation across the threshold of a suitable doorset.
The 75mm-wide profile creates a firm, smooth and continuous surface beneath the door. This gives a compatible automatic drop seal or door-bottom gasket a reliable surface against which to close.
It can also cover a suitable junction between adjoining floor finishes, helping create a neat transition through the doorway.
The current stocked range is available in:
- 1000mm length
- 2100mm length
Both stocked versions have a Satin Silver anodised finish and are supplied with mechanical fixings.
What is a threshold plate?
A threshold plate is a rigid profile installed on the floor beneath a door.
Its principal purpose is to provide an even sealing surface for a compatible door-bottom gasket.
Without a threshold plate, an automatic drop seal may need to close against:
- Uneven flooring
- Carpet
- Deep tile or grout joints
- Worn or damaged floor finishes
- A change between two flooring materials
- A floor that slopes across the doorway
- A narrow gap between adjoining finishes
These conditions can prevent the gasket from making continuous contact.
The NOR625 provides a stable aluminium platform across the doorway, helping the door-bottom seal close more consistently.
Designed for use with door-bottom seals
The NOR625 can be used beneath suitable automatic drop seals and other compatible door-bottom products.
As the door closes, the flexible gasket lowers or compresses against the upper face of the threshold plate.
A properly positioned plate can help provide:
- Continuous gasket contact across the opening
- A stable surface beneath the door
- Improved sealing over flooring joints
- Reduced localised gaps beneath the gasket
- A surface that is straightforward to inspect and clean
The automatic drop seal should be adjusted only after the threshold plate and final floor finishes have been installed.
The threshold plate does not seal independently
The NOR625 is an aluminium threshold plate rather than a flexible door seal.
It does not independently close the gap beneath the door.
For acoustic, smoke-control or draught-sealing applications, it normally needs to be combined with a compatible component such as:
- An automatic drop seal
- A flexible compression gasket
- A surface-mounted door-bottom seal
- Another approved threshold-sealing arrangement
The threshold plate provides the contact surface, while the flexible gasket creates the seal.
Acoustic door applications
The gap beneath a door can provide a direct path through which airborne sound passes.
The NOR625 can support an acoustic door-sealing system by helping the door-bottom gasket maintain contact across the complete doorway.
Final acoustic performance depends on the entire assembly, including:
- The mass and construction of the door leaf
- The door frame
- The perimeter seals around the head and jambs
- The automatic drop or door-bottom seal
- The position of the threshold plate
- The adjustment of the flexible gasket
- The adjoining floor construction
- The glazing and ironmongery
- The frame-to-wall junction
- The quality of installation
The NOR625 does not have a standalone decibel rating.
Any numerical sound-reduction figure applies to a complete tested doorset rather than to the aluminium plate alone.
Broader 75mm sealing surface
The NOR625 is 75mm wide, providing a broader surface than the 40mm-wide NOR615 threshold plate.
The additional width may be beneficial where:
- The drop-seal gasket has a wider landing position
- The floor transition extends further through the doorway
- The precise gasket position varies slightly as the door closes
- A broader contact platform is preferred
- A wider junction between floor finishes needs to be covered
The plate must still be positioned so that the complete gasket lands on its upper surface.
Smoke-control applications
A smooth and continuous threshold plate can help a compatible smoke-control gasket make reliable contact beneath a closed door.
The NOR625 itself is not a flexible smoke seal and should not be assigned an independent smoke classification.
Where smoke control is required, confirm:
- The approved automatic drop or threshold seal
- The permitted threshold-plate arrangement
- The maximum gap beneath the door
- The required head-and-jamb smoke seals
- The treatment of glazing and ironmongery
- The applicable test evidence or doorset assessment
Fire-door applications
The NOR625 is manufactured from aluminium and does not contain an intumescent fire-sealing element.
It does not independently provide an FD30, FD60 or other fire-resistance period.
Where it is installed beneath a fire-resisting door:
- Confirm that the threshold plate is permitted by the doorset evidence.
- Use the specified automatic drop or door-bottom seal.
- Maintain the required gap beneath the door.
- Do not interfere with the opening, closing or latching of the door.
- Use a fixing method appropriate to the floor construction.
- Confirm that the completed threshold meets applicable accessibility requirements.
Low-profile design
The NOR625 measures:
The low height creates a gradual transition across the doorway while the wider 75mm surface provides a generous landing area for a compatible gasket.
A correctly installed plate should:
- Sit flat against the underlying floor
- Have no raised or unsupported edges
- Remain clear of the door swing
- Have flush mechanical fixings
- Provide continuous support across its width
Approved Document M
Norseal describes the NOR625 as Document M compliant.
The low 4.9mm profile is intended to support accessible movement through suitable doorways.
The finished installation must still be assessed for:
- The difference between adjoining floor levels
- The exposed profile height
- Raised or sharp edges
- Wheelchair and mobility-aid access
- Trip and snagging risks
- The requirements applicable to the particular building
The product specification alone cannot make an incorrectly installed threshold compliant.
Suitable for pedestrian and wheeled traffic
When fully supported and securely fixed, the NOR625 provides a low transition suitable for normal movement through the doorway.
Potential traffic can include:
- Pedestrians
- Wheelchairs
- Mobility aids
- Pushchairs
- Cleaning equipment
- Light wheeled trolleys
The plate must not move, flex or lift under normal use.
Proud screw heads, loose edges or an unsupported profile can create a trip or snagging hazard.
Covers flooring transitions
The 75mm-wide NOR625 can cover a suitable junction between adjoining flooring materials.
Possible applications include transitions between:
- Carpet and vinyl
- Carpet and timber flooring
- Carpet and laminate
- Tile and resilient flooring
- Two different resilient floor finishes
- A floor finish and an existing sill
The plate should not be used to span a substantial unsupported void or major difference in floor level.
The underlying substrate must provide continuous support.
6063-T6 aluminium construction
The current manufacturer specification identifies the NOR625 as being manufactured from:
6063-T6 grade aluminium
The aluminium provides:
- A rigid gasket-contact surface
- Good dimensional stability
- Resistance to normal pedestrian wear
- A lightweight profile that can be cut on site
- A stable platform for compatible door-bottom seals
The plate must be supported by the floor rather than being expected to carry loads across an unsupported gap.
Anodised Satin Silver finish
The stocked product is described as Satin Silver anodised aluminium.
The current manufacturer sheet specifies an:
AA20 natural-anodised coating
The anodised surface provides:
- A neutral silver appearance
- Improved surface durability
- A suitable finish for commercial and public interiors
- A surface that can be cleaned easily
Cut ends should be deburred carefully so that no sharp aluminium remains exposed.
Screw-fixed or adhesive-bonded installation
The NOR625 can be installed using:
- Mechanical screw fixings
- A suitable adhesive
The stocked `/FX` versions are supplied with screws and plugs.
Adhesive is not supplied.
Mechanical fixing provides positive retention, while adhesive bonding can offer an installation without visible screw heads where the substrate and project specification permit it.
The chosen method must be compatible with:
- The floor substrate
- The expected level of traffic
- Any underfloor heating or concealed services
- The environmental conditions
- The doorset specification
- The adhesive manufacturer’s requirements
Optional concealed fixing
Norseal lists optional “invisible” fixing as a benefit of the NOR625.
This generally refers to an adhesive-bonded installation in which no screw heads are visible on the upper face.
An adhesive installation should only be used where:
- The substrate is suitable for bonding
- The selected adhesive is compatible with aluminium and the floor
- The adhesive can withstand the expected traffic
- The required curing conditions can be maintained
- The project specification permits adhesive fixing
Available lengths
The current stocked lengths are:
- 1000mm — suitable for standard-width single doors and cutting to shorter openings.
- 2100mm — suitable for wide openings, double doors and larger threshold dimensions.
Select a supplied length that is at least as long as the clear distance between the door jambs.
Can the NOR625 be cut to size?
Yes. The aluminium profile can be machine cut to the required doorway width.
The plate should be:
- Measured accurately between the jambs
- Marked with a square cutting line
- Cut using a suitable aluminium-cutting tool
- Deburred after cutting
- Cleaned of all aluminium swarf
- Trial fitted before drilling or bonding
Do not leave jagged, sharp or unfinished cut edges.
Compatible Norsound products
Subject to the applicable doorset specification, the NOR625 can provide a contact surface for suitable door-bottom seals including:
- NOR810 automatic drop seal
- NOR810S automatic drop seal
- NOR810S+ automatic drop seal
- NOR820 retrofit automatic drop seal
- Other compatible acoustic or smoke-control gaskets
The complete flexible gasket must land within the 75mm plate width when the door closes.
NOR625 or NOR615?
| Feature |
NOR625 |
NOR615 |
| Width |
75mm |
40mm |
| Height |
4.9mm |
4.9mm |
| Standard lengths |
1000mm and 2100mm |
1000mm and 2100mm |
| Primary difference |
Broader threshold and gasket-contact area |
More compact threshold width |
Select the profile according to the floor transition, gasket landing position and applicable doorset specification.
Typical applications
The NOR625 can be used within suitable doorsets in:
- Hotels and guest accommodation
- Apartment developments
- Schools and universities
- Hospitals and healthcare buildings
- Care homes
- Offices and meeting rooms
- Consultation and treatment rooms
- Libraries and study spaces
- Recording and broadcast spaces
- Commercial and public buildings
Key benefits
- Wide sealing surface — provides a 75mm platform beneath the door.
- Supports acoustic sealing — helps a door-bottom gasket maintain continuous contact.
- Low-profile design — measures only 4.9mm high.
- Floor-transition coverage — bridges a suitable junction between adjoining finishes.
- 6063-T6 aluminium — provides a durable and dimensionally stable profile.
- Anodised finish — current data specifies an AA20 natural-anodised coating.
- Satin Silver appearance — suits a wide range of doorsets and interiors.
- Document M compliant — described as such by the manufacturer.
- Suitable for accessible routes — when correctly installed within the complete doorway.
- Two fixing options — may be screw-fixed or adhesive bonded.
- Fixings included — supplied with both stocked `/FX` versions.
- Two available lengths — 1000mm and 2100mm.
- Can be cut to size — suitable for different doorway widths.
- Compatible with automatic drop seals — supports complete threshold-sealing systems.
Important buying advice
Before ordering, confirm:
- The clear distance between the door jambs
- Whether the 1000mm or 2100mm length is required
- That a 75mm plate is appropriate for the floor transition
- That the door-bottom gasket will land fully on the plate
- The floor and substrate construction
- Whether screw or adhesive fixing will be used
- Whether underfloor heating or concealed services are present
- The relationship between the adjoining floor levels
- The acoustic, smoke and accessibility requirements
- Whether the threshold arrangement is permitted by the doorset evidence
Norsound NOR625 Threshold Plate – 75 × 4.9mm Technical Specifications
Norsound NOR625 Threshold Plate is a low-profile, natural-anodised aluminium plate for installation at the threshold of suitable doorsets.
Product Specification
| Product Name |
Norsound NOR625 Threshold Plate – 75 × 4.9mm |
| Brand |
Norsound by Norseal |
| Manufacturer Product Reference |
NOR625 |
| Supplier Product Reference |
NOR6/25 |
| Product Type |
Low-profile aluminium doorset threshold plate |
| Application |
At the threshold of suitable doorsets |
| Primary Function |
Provides an even contact surface for a compatible door-bottom seal |
| Secondary Function |
Covers a suitable transition between adjoining floor finishes |
| Width |
75mm |
| Overall Height |
4.9mm |
| Profile Size |
75 × 4.9mm |
| Material |
6063-T6 grade aluminium |
| Current Manufacturer Coating |
AA20 natural-anodised coating |
| Stocked Finish Description |
Satin Silver anodised aluminium |
| Available Lengths |
1000mm and 2100mm |
| Fixing Methods |
Mechanically screw-fixed or adhesive bonded |
| Invisible-Fixing Option |
Yes — adhesive bonding can avoid exposed screw heads where suitable |
| Adhesive Supplied? |
No |
| Fixings Supplied with Stocked Versions? |
Yes — both stocked codes have the /FX suffix |
| Accessibility |
Described by Norseal as Document M compliant |
| Automatic Drop Seal Included? |
No |
| Flexible Gasket Included? |
No |
| Standalone Acoustic Rating? |
No — performance depends on the complete doorset and compatible door-bottom seal |
| Standalone Smoke Classification? |
No — the plate does not independently create a flexible smoke seal |
| Standalone Fire Rating? |
No — the plate does not independently provide a fire-resistance period |
| Intumescent Material |
No |
Available Lengths and Product Codes
| Length |
Profile Size |
Finish |
Fixings |
Product Code |
| 1000mm |
75 × 4.9mm |
Satin Silver anodised aluminium |
Included |
NOR6/25/1000/FX |
| 2100mm |
75 × 4.9mm |
Satin Silver anodised aluminium |
Included |
NOR6/25/2100/FX |
Manufacturer Product-Code Format
Norseal’s manufacturer literature uses the following general format:
- NOR625-1000 — 1000mm plate only
- NOR625-2100 — 2100mm plate only
- NOR625-1000/FX — 1000mm plate with fixings
- NOR625-2100/FX — 2100mm plate with fixings
The exact stocked product codes use the alternative supplier format:
- NOR6/25/1000/FX
- NOR6/25/2100/FX
Both sets of references identify the NOR625 75 × 4.9mm threshold profile.
Current Stocked Range
| Profile Size |
Length Options |
Finish Options |
Total Combinations |
| 75 × 4.9mm |
1000mm and 2100mm |
Satin Silver anodised aluminium |
2 |
Length Selection
Choose a supplied plate that is longer than or equal to the clear distance between the door jambs.
The 1000mm version is generally suitable for:
- Standard-width single doors
- Narrower internal openings
- Cutting to shorter threshold dimensions
The 2100mm version is generally suitable for:
- Wide single doors
- Double doorsets
- Unusually wide openings
- Long threshold transitions
Compatibility with Door-Bottom Seals
The selected door-bottom gasket should land completely on the aluminium plate when the door closes.
Check:
- The position of the door leaf
- The position of the automatic drop seal
- The gasket width
- The direction of door swing
- The relationship between the plate and door stops
- The finished floor levels
The wider 75mm surface offers additional tolerance compared with a 40mm threshold but must still be positioned accurately.
Acoustic Performance Note
The NOR625 can support acoustic performance by providing a stable surface for the door-bottom seal.
It must not be assigned a standalone sound-reduction value.
Final acoustic performance depends on:
- The construction of the door leaf
- The door frame
- The perimeter seals
- The automatic drop or threshold seal
- The gasket adjustment
- The position of the NOR625
- The floor and wall construction
- The glazing and ironmongery
- The quality of installation
Smoke Performance Note
The aluminium plate itself does not provide flexible smoke sealing.
Where smoke control is required:
- Use a compatible smoke-control door-bottom gasket.
- Follow the tested threshold arrangement.
- Maintain the specified gap beneath the door.
- Provide the required head-and-jamb seals.
- Confirm continuous gasket contact across the threshold.
Fire-Door Performance Note
The NOR625 is not an intumescent product.
Before installing it beneath a fire-resisting door:
- Confirm that the threshold plate is permitted by the doorset evidence.
- Confirm the approved door-bottom seal.
- Maintain the specified threshold gap.
- Do not obstruct the door swing.
- Confirm that the door continues to self-close and latch.
Document M Note
Norseal describes the NOR625 as Document M compliant.
The finished installation should nevertheless be assessed for:
- The final threshold height
- Changes between adjoining floor levels
- Exposed edges
- Trip and snagging hazards
- Wheelchair and mobility-aid access
- The requirements applicable to the particular building
Substrate Compatibility
The chosen fixing system must be appropriate for the underlying floor.
Potential substrates can include:
- Concrete
- Screed
- Timber
- Plywood
- Tile
- Resilient flooring
- Suitable floor-transition systems
Check for underfloor heating, pipework, electrical cables and other concealed services before drilling.
Handling and Storage
Store the NOR625:
- Flat and fully supported
- In a clean and dry location
- Protected from bending and twisting
- With the anodised surface protected from scratches
- Away from cement contamination and wet trades
- With the supplied fixings retained until installation
Inspection and Maintenance
Inspect the installed threshold regularly.
Check for:
- Loose fixings
- Proud screw heads
- Movement under pedestrian or wheeled traffic
- Failure of an adhesive bond
- Bent or raised edges
- Sharp cut ends
- Debris affecting the door-bottom gasket
- Loss of alignment beneath the automatic drop seal
- Changes in the adjoining flooring
Keep the upper surface clean so the flexible gasket can make continuous contact.
How to Install the Norsound NOR625 Threshold Plate – 75 × 4.9mm
Norsound NOR625 Threshold Plate can be mechanically screw-fixed or bonded using a suitable adhesive.
The plate should be cut to the clear distance between the door jambs and positioned so that the compatible door-bottom gasket lands fully on the 75mm-wide upper surface.
What You’ll Need
- Norsound NOR625 in the appropriate 1000mm or 2100mm length
- The supplied screws and plugs for mechanical installation
- A suitable threshold adhesive where adhesive fixing is selected
- The applicable doorset and flooring specification
- Tape measure
- Pencil or fine permanent marker
- Square or straight edge
- Machine saw suitable for aluminium
- File or deburring tool
- 4mm metal drill bit
- Countersink bit
- 6mm masonry drill bit where fixing into concrete
- Drill and screwdriver
- Straight edge or spirit level
- Vacuum or brush
- Clean lint-free cloth
- Safety glasses
- Hearing protection
- Protective gloves
Before You Start
Inspect the doorway, door and floor.
Confirm that:
- The door opens, closes and latches correctly.
- The frame and jambs are secure.
- The automatic drop or door-bottom seal is correctly installed.
- The threshold plate is permitted by the doorset evidence.
- The 75mm plate width is suitable for the gasket and flooring transition.
- The floor can provide continuous support beneath the plate.
- The plate will not span a large unsupported gap.
- The completed threshold will not obstruct the door swing.
- No underfloor heating, cables or pipes will be damaged by drilling.
- The selected fixing method is suitable for the substrate.
Complete the final adjustment of the door-bottom seal only after the threshold plate has been installed.
Step 1: Measure Between the Door Jambs
Measure the clear distance between the two door jambs at floor level.
Record this dimension as L.
Measure at the exact location where the threshold plate will sit.
Do not assume that the opening is perfectly square or that a measurement taken higher up the frame will be identical.
Step 2: Check the Gasket Landing Position
Close the door and identify where the automatic drop-seal or door-bottom gasket will land.
Position the NOR625 so that:
- The gasket lands completely on the aluminium.
- The gasket does not extend beyond either plate edge.
- The plate covers the required floor transition.
- The profile remains clear of the door swing.
- The finished position provides a suitable accessible transition.
Mark the intended plate position on the floor.
Step 3: Check the Adjoining Floor Levels
Place a straight edge across the doorway and inspect the adjoining floor finishes.
Confirm that:
- The 4.9mm profile will sit securely.
- The plate will be supported across its full width.
- No edge will be left unsupported.
- The plate will not rock or flex.
- The profile will not create an unacceptable trip hazard.
Prepare or level the substrate where necessary before installation.
Step 4: Transfer the Measurement
Place the NOR625 on a stable work surface.
Measure dimension L along the profile and mark the cutting position.
Use a square to mark a line perpendicular to the length of the aluminium plate.
Check the measurement again before cutting.
Step 5: Machine Cut the Plate
Cut the NOR625 to the required length using a suitable machine saw for aluminium.
Support the 75mm-wide profile firmly during cutting.
Use controlled pressure to avoid:
- Bending the aluminium
- Damaging the anodised finish
- Producing an angled cut
- Creating a jagged edge
- Twisting the plate
Wear appropriate eye, hand and hearing protection.
Step 6: Deburr the Cut Edge
Use a file or deburring tool to remove:
- Sharp edges
- Raised burrs
- Loose aluminium swarf
- Uneven material that could prevent the plate sitting flat
Clean the profile thoroughly after cutting.
No sharp aluminium should remain exposed beside either jamb.
Step 7: Dry Fit the Threshold Plate
Place the cut NOR625 between the jambs in its intended position.
Check that:
- The length fits correctly.
- The plate lies flat.
- Both ends finish neatly against the jambs.
- The profile follows the marked alignment.
- The door opens and closes freely.
- The door-bottom gasket aligns with the plate.
- The plate adequately covers the floor transition.
Correct the length or position before drilling or applying adhesive.
Step 8: Select the Fixing Method
The NOR625 can be installed using:
- Mechanical screw fixing
- Adhesive bonding
Select the method according to:
- The floor material
- The expected level of traffic
- The presence of underfloor services
- The doorset specification
- The project’s appearance requirements
The stocked `/FX` versions include screws and plugs.
Adhesive is not supplied.
Mechanical Screw-Fixing Method
Step 9: Mark the Fixing-Hole Positions
Mark fixing positions along the threshold plate at approximately:
200mm centres
Keep the end holes suitably clear of the cut edges.
Distribute the fixing positions so that the complete plate is retained evenly and no section can lift under traffic.
Step 10: Drill the Aluminium Plate
Using a 4mm metal drill bit, drill through the plate at each marked position.
Support the aluminium on a suitable backing surface.
Remove metal swarf after drilling.
Step 11: Countersink Each Hole
Countersink the fixing holes so that the supplied screw heads can finish flush with the top surface.
Do not countersink excessively.
An oversized or overly deep countersink can:
- Reduce the aluminium thickness around the hole
- Allow the screw to pull through
- Distort the profile
- Create an uneven gasket-contact surface
Step 12: Transfer the Hole Positions
Return the drilled plate to its final location.
Mark the floor through each fixing hole while maintaining the correct plate alignment.
Remove the plate once every position has been transferred.
Step 13: Check for Concealed Services
Before drilling the substrate, establish whether the fixing positions could affect:
- Underfloor heating pipes
- Electrical cables
- Water or heating pipes
- Floor membranes
- Structural components
- Other concealed services
Use a suitable alternative fixing method where safe drilling cannot be confirmed.
Step 14: Drill a Concrete Floor
Where fixing into concrete, use a:
6mm masonry drill bit
Drill each marked position to the depth required by the supplied plugs.
Keep the drill perpendicular to the floor and remove dust from the holes.
For timber or another substrate, select the drill and fixings appropriate to that material.
Step 15: Insert the Plugs
Insert the supplied plugs into the drilled concrete holes.
Each plug should finish flush with the floor surface.
A projecting plug can prevent the plate from lying flat.
Step 16: Screw the Plate into Position
Place the NOR625 in its final position.
Insert the supplied screws through the countersunk holes and tighten them progressively.
Work along the plate while checking its alignment and flatness.
Every screw head must finish:
Flush with the upper surface of the threshold plate
Proud fixings can interfere with the door-bottom gasket and create a snagging point.
Step 17: Avoid Overtightening
Tighten each screw sufficiently to secure the plate without distorting the aluminium.
Overtightening can:
- Dish the aluminium around the fixing hole
- Create an uneven sealing surface
- Pull the plate out of alignment
- Cause the profile edges to lift
- Damage the underlying floor
Check that the complete plate remains flat after fixing.
Adhesive-Bonding Method
Step 18: Select a Suitable Adhesive
Choose an adhesive compatible with:
- Anodised aluminium
- The underlying floor substrate
- The expected pedestrian and wheeled traffic
- The environmental conditions
- The required curing conditions
Follow the adhesive manufacturer’s requirements for:
- Surface preparation
- Application temperature
- Bead size
- Open time
- Curing time
- Temporary restraint
Step 19: Prepare the Bonding Surfaces
The floor and underside of the plate must be:
- Clean
- Dry
- Stable
- Free from dust
- Free from grease and oil
- Free from loose coatings
- Free from old adhesive residue
- Compatible with the selected adhesive
Allow any cleaning product to dry completely.
Step 20: Apply Adhesive to Both Channels
Turn the NOR625 over and identify the two adhesive channels on its underside.
Apply a continuous bead of suitable adhesive along the complete length of both channels.
Avoid:
- Leaving breaks in either bead
- Applying excessive adhesive
- Contaminating the visible anodised surface
- Allowing adhesive onto the gasket-contact area
Step 21: Position the Plate
Place the NOR625 onto the prepared floor in its marked position.
Press evenly along its full length and width.
Check that:
- The plate remains straight.
- Both ends remain correctly positioned.
- The profile sits flat.
- The upper surface remains clean.
- Excess adhesive is removed as directed by its manufacturer.
Step 22: Allow the Adhesive to Cure
Protect the threshold until the adhesive has cured fully.
Do not expose it prematurely to:
- Pedestrian traffic
- Wheelchairs or trolleys
- Door-seal adjustment
- Cleaning
- Impact or sideways movement
Use temporary restraint where required by the adhesive manufacturer.
Step 23: Inspect the Completed Threshold
After fixing, confirm that:
- The NOR625 is secure.
- The plate lies flat.
- No edge is raised.
- No screw head is proud.
- No sharp cut edge is exposed.
- The profile does not move under foot pressure.
- The door opens and closes freely.
- The threshold remains suitable for pedestrian and wheeled traffic.
Step 24: Adjust the Automatic Drop Seal
Close the door and observe the flexible door-bottom gasket.
Adjust the seal so that the gasket:
- Lowers onto the NOR625 as the door closes
- Makes continuous contact across the threshold
- Lands fully within the 75mm plate width
- Is not compressed more than necessary
- Retracts fully when the door opens
- Does not prevent the door from closing or latching
The threshold plate itself has no adjustment mechanism.
Step 25: Complete the Final Door Check
Operate the door several times.
Confirm that:
- The door opens freely.
- The door closes completely.
- The latch engages correctly.
- The self-closing device remains effective where fitted.
- The gasket contacts the threshold continuously.
- The threshold plate remains secure.
- No edge or fixing creates a trip or snagging hazard.
Installation Tips
- Measure the doorway between the jambs at floor level.
- Check where the door-bottom gasket will land before cutting.
- Confirm that the broader 75mm width suits the floor transition.
- Machine cut the aluminium accurately.
- Deburr every cut edge.
- Dry fit the profile before drilling or bonding.
- For screw fixing, use 4mm holes at approximately 200mm centres.
- Countersink every fixing hole.
- For concrete, use a 6mm masonry drill for the supplied plugs.
- Ensure every screw head finishes flush.
- Check for concealed services before drilling.
- For adhesive fixing, apply a continuous bead in both underside channels.
- Allow the adhesive to cure completely.
- Adjust the automatic drop seal after the plate has been installed.
- Keep the aluminium sealing surface clean.
Maintenance Advice
Inspect the NOR625 regularly.
Check for:
- Loose screws
- Proud fixing heads
- Failure of an adhesive bond
- Raised profile edges
- Movement beneath traffic
- Bending or distortion
- Sharp or damaged cut ends
- Accumulated dirt affecting gasket contact
- Loss of alignment beneath the drop seal
- Changes in the adjoining floor finishes
Clean the plate using a soft cloth and a mild product suitable for anodised aluminium.
Avoid:
- Strong acidic or alkaline cleaners
- Abrasive pads
- Steel wool
- Sharp scraping tools
- Paint or adhesive contamination on the gasket-contact surface
Important Performance Note
Correct measuring, cutting, fixing and door-bottom-seal adjustment are essential.
The NOR625 does not independently create an acoustically rated, smoke-control or fire-resisting doorset.
Final performance depends on:
- The door leaf and frame
- The perimeter sealing system
- The automatic drop or door-bottom seal
- The position of the threshold plate
- The adjustment of the flexible gasket
- The adjoining floor construction
- The glazing and ironmongery
- The quality of installation and maintenance
For certified or performance-rated doorsets, install the NOR625 only in accordance with the applicable test evidence, assessment and door-manufacturer instructions.