Norsound NOR810 Automatic Drop Seal – 14 × 35mm is a high-performance rebated door-bottom seal designed to reduce sound, cold smoke, draughts, light and unwanted airflow through the gap beneath an acoustic timber doorset.
The NOR810 is mortised into a groove along the bottom edge of the door leaf, creating a discreet installation with the aluminium mechanism concealed within the door.
When the door closes, a single actuator activates the internal mechanism and lowers the grey silicone gasket onto the floor, sill or threshold plate.
As the door opens, the gasket automatically retracts into the aluminium housing, helping prevent it from dragging continuously across the floor.
The NOR810 is designed to treat the gap beneath a timber door.
Even where a door leaf provides strong acoustic performance, an untreated threshold gap can allow sound, smoke, draughts and light to pass between adjoining spaces.
The NOR810 can be used to:
The NOR810 contains a mechanically operated internal drop mechanism.
An actuator is positioned at the hinge side of the door. As the door reaches its closed position, the actuator contacts the frame and activates the mechanism.
The silicone gasket then lowers towards the floor or threshold.
When the door starts to open, pressure is released from the actuator and the gasket retracts into the aluminium housing.
No electrical power, cabling or control connection is required.
The NOR810 uses a single actuator to operate the drop mechanism.
The actuator should be positioned at the hinge side of the door so it contacts the frame as the door closes.
The actuator can be adjusted to control the amount of gasket travel required for the actual threshold gap.
The seal should be adjusted so that the gasket makes continuous contact when the door is closed without being compressed further than necessary.
The internal mechanism is designed to lower the gasket across the width of the door.
The self-levelling action helps the silicone gasket maintain contact where the floor, sill or threshold is not completely level.
Self-levelling does not compensate for:
A suitable threshold plate may be required where the existing floor does not provide a smooth and stable sealing surface.
The NOR810 can cover a threshold gap of up to 20mm.
The actual permissible gap may also be restricted by:
The gasket should make light and continuous contact. Excessive travel can increase closing resistance and place unnecessary strain on the mechanism.
The NOR810 has been acoustically tested in accordance with BS EN ISO 10140-2.
It is intended for use at the bottom edge of acoustic timber doorsets and can help reduce sound leakage through the threshold gap.
The NOR810 does not have a universal standalone decibel rating.
Any published sound-reduction figure applies to a complete tested door assembly rather than the drop seal alone.
Final acoustic performance depends on:
For effective sound control, the complete perimeter of the door must be sealed rather than treating only the bottom edge.
The NOR810 has been smoke tested in accordance with BS 476-31.1.
When correctly installed and adjusted, the silicone gasket helps restrict cold smoke passing through the gap beneath the closed door.
Smoke containment depends on the complete doorset, including:
Smoke testing does not provide an independent fire-resistance rating.
Norseal states that the NOR810 is suitable for use on most fire doors and is compliant with BS 476-22 within relevant tested applications.
The product is associated with:
This does not mean that the NOR810 independently gives a door a particular fire-resistance period.
Before routing a fire-resisting door, confirm:
Unauthorised machining may invalidate the certification or assessment applying to the door.
The NOR810 is installed into a routed groove along the bottom edge of the door leaf.
The main aluminium housing measures:
The seal is secured at the ends using the appropriate end plates or end caps.
Once installed, the main mechanism is concealed within the door, leaving the silicone gasket to lower from the bottom edge when activated.
The NOR810 has a mill-finish aluminium housing.
The aluminium profile provides:
The visible end components and gasket are normally light grey.
The flexible sealing element is manufactured from silicone.
Silicone provides:
The gasket should be kept free from cuts, paint, adhesive and accumulated floor debris.
The NOR810 has been tested to 1,000,000 operating cycles.
This makes it suitable for frequently used doors in environments such as:
Cycle testing relates to the tested product mechanism and does not remove the need for routine inspection and maintenance.
The NOR810 can be used within suitable:
The door must be thick enough and constructed appropriately to receive the 14mm-wide × 35mm-deep mortise.
Yes. The NOR810 can close against a suitable floor, sill or threshold plate.
A threshold plate is particularly useful where the existing floor is:
A smooth and stable threshold helps the gasket maintain continuous contact across the doorway.
After fitting or changing a threshold plate, the actuator should be readjusted.
Yes. A suitable acoustic or smoke perimeter seal should normally be fitted around the:
The NOR810 then treats the remaining gap beneath the door.
The perimeter and threshold products must be compatible with the applicable acoustic, smoke or fire doorset evidence.
The standard available lengths are:
Norseal also states a maximum manufactured length of 1700mm. Special lengths are not included within the standard options listed above and should be confirmed before ordering.
The NOR810 can be shortened to suit the measured door width.
Cut-back allowances vary by supplied length.
The manufacturer states:
Never shorten the product beyond the stated limit, as this can damage the internal mechanism.
Before ordering, confirm:
Do not machine a fire-rated, hollow-core, glazed or specialist door until the proposed drop-seal installation has been checked against the door manufacturer’s evidence.
Norsound NOR810 Automatic Drop Seal is a rebated, mechanically operated door-bottom seal with an aluminium housing, grey silicone gasket and single-actuation mechanism.
| Product Name | Norsound NOR810 Automatic Drop Seal – 14 × 35mm |
| Brand | Norsound by Norseal |
| Product Reference | NOR810 |
| Product Type | Rebated automatic acoustic and smoke door-bottom seal |
| Application | Bottom edge of acoustic timber doorsets |
| Installation Method | Mortised into the bottom edge of the door and retained using end plates or end caps |
| Profile Width | 14mm |
| Profile Depth | 35mm |
| Maximum Gap Coverage | 20mm |
| Actuation | Single mechanical actuator |
| Actuator Position | Hinge side of the door |
| Adjustment | Adjustable actuator controlling the amount of gasket travel |
| Adjustment Direction | Clockwise reduces gasket travel; anti-clockwise increases gasket travel |
| Self-Levelling | Yes |
| Parallel Drop Mechanism | Yes |
| Power Requirement | None — mechanically operated |
| Housing Material | Aluminium |
| Gasket Material | Silicone |
| Housing Finish | Mill-finish aluminium |
| Gasket Colour | Grey |
| Acoustic Test Standard | BS EN ISO 10140-2 |
| Smoke Test Standard | BS 476-31.1 |
| Fire Standard Referenced | BS 476-22 |
| Certifire Approval | Certificate CF629 within relevant approved arrangements |
| Additional Approval | UL approval |
| Durability | Tested to 1,000,000 operating cycles |
| Standard Length Range | 320mm to 1535mm |
| Maximum Manufacturer Length | 1700mm, subject to special-order availability |
| Cut-Back | Varies by length; generally more than 100mm, with the 320mm version limited to approximately 85mm |
| Minimum Finished Length | Approximately 235mm when shortening the 320mm version within its stated limit |
| Suitable Door Configurations | Suitable single- and double-leaf timber doorsets, subject to the complete doorset specification |
| Standalone Acoustic Rating? | No — acoustic performance depends on the complete tested door assembly |
| Standalone Fire Rating? | No — fire performance depends on the complete tested or assessed doorset |
| Length | Profile Size | Finish | Product Code |
|---|---|---|---|
| 320mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/0320 |
| 435mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/0435 |
| 535mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/0535 |
| 635mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/0635 |
| 735mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/0735 |
| 835mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/0835 |
| 935mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/0935 |
| 1035mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/1035 |
| 1135mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/1135 |
| 1235mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/1235 |
| 1335mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/1335 |
| 1435mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/1435 |
| 1535mm | 14 × 35mm | Mill finish / Grey gasket | NOR810/1535 |
Norseal’s general manufacturer code format is:
NOR810 + supplied length
For example:
The product codes in the table above use the slash-separated format contained within the current supplied product range.
The correct supplied length should be chosen so it can be shortened to the required door width without exceeding its cut-back limit.
Important points include:
The NOR810 has been tested in accordance with BS EN ISO 10140-2.
The individual seal should not be given a universal standalone decibel rating.
Final acoustic performance depends on:
The NOR810 has been smoke tested in accordance with BS 476-31.1.
The silicone gasket must make continuous contact with a suitable floor or threshold surface when the door is closed.
Where smoke control is required, the complete doorset must also include suitable seals around the door head and jambs.
Norseal identifies the NOR810 as suitable for use on most fire doors and compliant with BS 476-22 within relevant tested arrangements.
This does not provide a standalone fire rating for the seal.
Before installing it into a fire-resisting door:
The NOR810 can close against a suitable floor, sill or threshold plate.
A threshold plate may be beneficial where the existing surface is:
The actuator must be adjusted after the final threshold surface has been installed.
Store the NOR810:
Do not allow debris to enter the internal drop mechanism.
Norsound NOR810 Automatic Drop Seal is rebated into a routed groove along the bottom edge of a suitable timber door leaf.
The actuator must be positioned at the hinge side of the door, and the selected seal must not be shortened beyond the cut-back limit marked on the product.
Always check the current Norsound fitting instructions and the evidence for the complete doorset before machining a fire-rated or specialist door.
Inspect the door, frame and threshold.
Confirm that:
Do not machine a fire-rated, hollow-core, glazed or specialist door without checking the manufacturer’s evidence.
Remove the NOR810 from its packaging and identify:
Do not begin cutting until the individual product’s permitted cut-back has been confirmed.
The 320mm version is limited to approximately 85mm of cut-back. Other standard lengths generally provide more than 100mm, but the product label remains the controlling instruction.
Remove the door from its hinges where necessary.
Lay it securely on its side and support it across its length.
Restrain the door so it cannot move while being routed or cut.
Protect:
Mark the position of the NOR810 along the bottom edge of the door.
The required main mortise is:
Keep the groove straight and aligned with the position required by the doorset specification.
Check that sufficient door material will remain on both faces after routing.
Position the end plates against the ends of the seal and mark any shallow recesses required by the fitting arrangement.
The end plates should sit neatly against the door edge without twisting or distorting the aluminium housing.
Use the supplied end components as the template rather than relying solely on nominal dimensions.
Use a router, suitable cutter and guide to machine the 14 × 35mm groove.
Remove the timber in controlled passes rather than attempting the full depth in one operation.
Maintain:
Avoid cutting into structural rails, glazing systems, hardware or other door components.
Remove all timber dust, chips and loose fibres.
Use a brush or vacuum to ensure the mortise is clear.
Check that:
Measure the door width accurately at the bottom edge.
Allow for the thickness and clearance required by the end plates in accordance with the current fitting guide.
The fitted seal should sit neatly between the door edges without binding against the end plates.
Check the required finished length against the product’s stated cut-back limit.
Mark the required finished length on the permitted cutting end.
Before cutting, confirm:
Never cut through the actuator end unless the current fitting instructions specifically permit it.
Pull or slide the silicone gasket away from the cutting line.
Move enough gasket clear of the saw so it cannot be damaged.
Do not:
Support the NOR810 securely and cut the aluminium housing at the marked position using a suitable fine-tooth saw.
Keep the cut square.
After cutting:
Do not leave metal debris inside the seal.
Return the silicone gasket to its natural position.
Trim it cleanly to the required finished length.
Do not stretch the gasket while cutting, as it may retract and finish too short.
Check that the gasket remains:
Place the prepared seal into the routed groove.
The actuator must be positioned at the hinge side of the door.
Check that:
Mark and drill suitable pilot holes for the end-plate screws.
Secure the NOR810 using the correct end plates and fixings.
Tighten the screws sufficiently to retain the seal without distorting the end plates or aluminium housing.
Excessive tightening can:
Return the door to the frame and secure it correctly to the hinges.
Check that:
Close the door slowly while observing the gasket.
The silicone seal should:
Adjust the actuator in small increments:
Close and reopen the door after each adjustment.
Continue until the gasket makes light, continuous contact with the threshold when the door is fully closed.
The silicone gasket does not need to be completely compressed.
Excessive actuator travel can:
Reduce the actuator travel if the gasket is heavily compressed.
Close the door and inspect the gasket across its full width.
Confirm that:
Where the floor is too uneven or compressible, fit a suitable threshold plate rather than over-adjusting the seal.
Operate the door several times.
Confirm that:
Where a threshold plate is required, install and secure it before completing the final actuator adjustment.
The threshold plate should:
Readjust the NOR810 after the final floor or threshold surface has been completed.
The NOR810 treats the gap beneath the door.
Suitable perimeter seals are normally required around the:
Use the complete sealing arrangement specified by the applicable acoustic, smoke or fire doorset evidence.
Inspect and operate the NOR810 regularly as part of the door-maintenance programme.
Check for:
Clean the silicone gasket and threshold using a soft cloth and a suitable mild cleaning product.
Do not apply unapproved oil, grease or lubricant to the internal mechanism.
Correct machining, cutting, fixing and actuator adjustment are essential to the operation of the NOR810.
The product does not independently create an acoustically rated, smoke-control or fire-resisting door.
Final performance depends on:
For certified doorsets, install the NOR810 only in accordance with the applicable test evidence, assessment, certification and door-manufacturer instructions.
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