Norseal Fire-Rated Letterplate – Black Frame is a telescopic door letterplate designed for use within approved fire-resisting timber doorsets.
The unit combines a black plastic frame with aluminium internal and external flaps, an integrated brush draught seal and a concealed intumescent liner around the telescopic sleeve.
It is available in two sizes:
Each size is available with either Gold or Satin Anodised Aluminium flaps.
Installing a letterplate requires an aperture to be cut through the door leaf. On a fire-resisting door, this opening can create a significant weakness unless the letterplate and its protection system have suitable supporting fire-test evidence.
The Norseal letterplate includes an intumescent liner that wraps around the telescopic sleeve. During fire conditions, the liner expands to help protect and close the aperture around the letterplate assembly.
The product has published fire-performance evidence for suitable 44mm and 54mm timber doors, providing up to 60 minutes of fire integrity when installed as part of an approved doorset construction.
The letterplate must not be described as independently making a door FD30 or FD60. Fire performance belongs to the complete tested or assessed doorset, including:
The internal and external sections connect through the prepared door aperture to form a telescopic sleeve.
This arrangement allows the two faceplates to sit against opposite faces of the door while creating a protected passage for letters and small postal items.
The correct door-thickness compatibility must be confirmed before installation. Published product information identifies suitable arrangements for 44mm and 54mm timber doors.
An intumescent liner is supplied with the letterplate and must be wrapped around the outside of the telescopic sleeve before the door aperture is measured or cut.
The liner is supplied at the length required for the assembly and must not be shortened. The manufacturer’s instructions expressly require the complete liner to be used.
Once fitted, the liner is concealed within the door aperture.
The letterplate incorporates a brush seal around the opening to help reduce ordinary draughts through the postal aperture.
The brush does not replace the intumescent liner and must not automatically be assigned a separate cold-smoke classification.
Where a doorset requires ambient-temperature smoke containment, confirm that the complete door and letterplate arrangement has appropriate supporting smoke-test evidence.
The internal and external flaps are manufactured from aluminium and are designed to open through approximately 180 degrees.
The anti-snap flap design helps the flap move fully out of the way during use rather than being forced against a limited stop.
The available flap finishes are:
Both finishes are supplied with the same fixed black frame.
10-inch letterplate
12-inch letterplate
These measurements describe the product assembly. Do not cut the door aperture using the faceplate dimensions.
The required aperture must be measured from the assembled outer telescopic sleeve after the complete intumescent liner has been fitted.
Published product information identifies testing through 15,000 operating cycles and water resistance up to 200Pa under the referenced test arrangement.
These performance values apply to the tested product configuration and do not remove the need for routine inspection.
The letterplate should be checked periodically for:
Subject to the complete doorset evidence, the letterplate may be used in suitable timber entrance doors where postal access is required.
Before specifying the product, confirm:
Before ordering, confirm:
| Product Range | Norseal Advantage fire-rated letterplate |
| Product Type | Telescopic fire-rated door letterplate |
| Application | Approved fire-resisting timber doorsets |
| Frame Colour | Black |
| Frame Material | Plastic telescopic frame |
| Flap Material | Aluminium |
| Stocked Flap Finishes | Gold and Satin Anodised Aluminium |
| Stocked Sizes | 10-inch and 12-inch |
| Published Door Thicknesses | 44mm and 54mm timber doors |
| Fire Performance | Up to 60 minutes as part of a suitable tested or assessed doorset |
| Fire-Test Standard | BS 476-22 |
| Intumescent Protection | Self-adhesive liner wrapped around the telescopic sleeve |
| Draught Protection | Integrated brush draught seal |
| Flap Opening | Approximately 180 degrees |
| Published Durability Test | 15,000 operating cycles under TS32 |
| Published Water Resistance | Up to 200Pa under BS 5368-3 |
| Fixing | Bolted through the door with additional supplied corner screws |
| Intumescent Mastic Required | Yes — applied behind both faceplates; not stated as supplied |
| Standalone Fire Rating? | No — performance applies to the complete tested or assessed doorset |
| Standalone Cold-Smoke Rating? | No separate cold-smoke classification should be assumed |
| Unit of Sale | One complete letterplate assembly |
| Nominal Size | Approximate Overall Dimensions | Approximate Internal Opening |
|---|---|---|
| 10-inch | 272 × 70mm | 221 × 37mm |
| 12-inch | 306 × 70mm | 254 × 37mm |
The required door aperture is not the same as the overall faceplate dimensions. Measure the outer telescopic sleeve after the supplied intumescent liner has been fitted.
| Size | Frame | Flap Finish | Product Code |
|---|---|---|---|
| 10-inch | Black | Gold | LET/10/BK/GLD |
| 10-inch | Black | Satin Anodised Aluminium | LET/10/BK/SAA |
| 12-inch | Black | Gold | LET/12/BK/GLD |
| 12-inch | Black | Satin Anodised Aluminium | LET/12/BK/SAA |
| Size Options | Frame Options | Flap-Finish Options | Total Variations |
|---|---|---|---|
| 10-inch and 12-inch | Black | Gold and Satin Anodised Aluminium | 4 |
Intumescent mastic is required by the fitting instructions but is not listed among the supplied components.
Before installation, verify:
The letterplate must be installed in accordance with the current Norseal fitting guide and the evidence for the complete fire doorset.
Cutting an aperture into a fire door can invalidate its certification where the opening, position or hardware is not permitted. Confirm the doorset specification before machining the door.
Confirm:
Check that the package contains:
Do not proceed where the liner or any fixing component is missing or damaged.
Remove the self-adhesive backing from the supplied intumescent liner.
Wrap the liner around the complete outside of the outer telescopic sleeve, ensuring that the adhesive makes full contact with the letterplate body.
Do not cut or shorten the liner.
The complete supplied length must be used so the sleeve remains protected around its full perimeter.
Measure the overall external dimensions of the telescopic sleeve after the intumescent liner has been fitted.
Use this assembled measurement to determine the required door aperture.
Do not use:
The intumescent liner affects the finished sleeve dimensions and must be included when measuring.
Mark the required aperture on the door leaf in the position permitted by the doorset evidence.
The Norseal fitting guide states that the aperture should be positioned no more than 1100mm from the bottom of the door.
Check that the marked aperture:
Drill suitable starting holes and cut the aperture carefully using appropriate equipment.
The opening should closely suit the measured telescopic sleeve and liner without crushing the intumescent material.
Remove loose material and clean the aperture before inserting the letterplate.
Do not enlarge the opening beyond the dimensions needed for the protected sleeve.
Apply a continuous bead of suitable intumescent mastic behind both letterplate faceplates.
The mastic should provide continuous contact between each faceplate and the door surface without obstructing the flap or telescopic opening.
Insert both sections of the letterplate into the prepared aperture.
The section carrying the intumescent liner must be positioned on the inside face of the door, as specified by the Norseal fitting instructions.
Check that:
Use the supplied bolts and screws to secure the letterplate through the door.
Select the appropriate supplied bolt length for the door thickness.
The standard Advantage installation requires one screw at each faceplate corner in addition to the connecting bolts.
Tighten the fixings evenly without distorting the plastic frame, damaging the door faces or restricting flap movement.
Clean away excess intumescent mastic with a damp cloth before it cures.
Do not remove the continuous mastic seal from behind the faceplates.
Open and release both flaps several times.
Confirm that:
Confirm that:
Inspect the letterplate as part of the fire-door inspection programme.
Check for:
The Norseal letterplate does not independently provide an FD30 or FD60 rating.
Its published fire performance depends on the complete tested or assessed doorset, correct aperture position, complete intumescent liner, required mastic, supplied fixings and installation quality.
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