Interdens 1mm DIN Lock Protection – Without Strike is a pre-cut intumescent lock mask designed to protect a compatible European sashlock or DIN lock case within a fire-resisting timber doorset.
The 1mm Interdens material is installed around the recessed lock body before the lock is secured within the door leaf. During fire conditions, the material expands into available spaces around the metal lock case, helping protect the surrounding timber and support the performance of the complete fire-door assembly.
This product contains the lock-body protection only. Intumescent protection for the strike plate or keep within the door frame is not included.
Installing a mortice lock requires a substantial recess to be formed within the edge of the door leaf. This removes part of the original door core and introduces a metal component capable of transferring heat into the surrounding timber.
The Interdens lock mask is fitted around the compatible lock case to help:
The kit should only be used where the relevant lock and doorset evidence permits an Interdens lock mask of this type and thickness.
Norseal describes the TH100 configuration as a lock mask for European sashlocks and DIN locks.
DIN-style lock cases generally follow standardised dimensional principles, but individual products can still differ in:
Confirm that the mask matches the exact lock model and the supporting fire-door specification before installation.
The product should not be treated as universally compatible with every mortice lock merely because the lock is described as DIN-sized.
This product protects the lock-body location in the door leaf but does not include an intumescent strike-plate pad for the door frame.
Where the tested or assessed doorset requires protection behind the strike plate or keep, that protection must be ordered and installed separately.
Do not assume that frame-side protection is unnecessary simply because it is not included with this product. The required arrangement must be confirmed from:
The mask is manufactured from 1mm Interdens, a low-pressure intumescent material used for protecting ironmongery within fire-resisting doorsets.
Interdens remains thin and discreet during normal use. When exposed to elevated temperatures, it expands into available spaces around the lock case.
Its low-pressure expansion characteristic makes it suitable for closely fitted hardware locations where controlled intumescence is required without unnecessarily forcing the ironmongery from its recess.
The Interdens material incorporates self-adhesive backing to assist accurate positioning around the lock case or within the prepared mortice pocket.
The adhesive helps retain the protection while the lock is inserted and mechanically secured.
The adhesive is an installation aid only. It does not replace:
The prepared mask reduces the need to manufacture individual protection pieces from loose intumescent sheet on site.
A pre-cut kit helps provide:
Dry-fit the complete mask before removing the adhesive liner. Do not trim, overlap or omit sections unless permitted by the current fitting instructions or doorset evidence.
Norseal lists its Interdens lock kits for lock and latch locations within fire-resisting doorsets, with fire resistance tested in accordance with BS 476-22.
The lock mask does not independently provide an FD30, FD60 or other fire-resistance classification.
The achieved performance depends on the complete assembly, including:
When a lock is removed from an existing fire door, inspect the intumescent protection before installing the replacement lock.
Replace the mask if it is:
A replacement lock should not automatically be fitted using the protection from the previous lock. The new lock and intumescent arrangement must remain supported by the complete doorset evidence.
Before ordering, confirm:
| Product Name | Interdens 1mm DIN Lock Protection – Without Strike |
| Product Code | INT/1/TH100 |
| Manufacturer Reference | INT(1)TH100 |
| Manufacturer Description | Lock Mask – European Sashlock/DIN Lock |
| Product Type | Pre-cut intumescent lock-body mask |
| Application | Compatible European sashlock and DIN lock locations within fire-resisting doorsets |
| Protection Supplied | Lock-body protection only |
| Strike Protection Included? | No |
| Material | Interdens |
| Thickness | 1mm |
| Colour | White |
| Fixing | Self-adhesive positioning, retained behind the mechanically fixed lock case |
| Expansion Characteristic | Low-pressure intumescent expansion |
| Published Activation Temperature | Approximately 180°C for Interdens material |
| Fire-Test Standard Referenced | BS 476-22 |
| Unit of Sale | One lock-protection kit |
| Lock Included? | No |
| Strike Plate Included? | No |
| Fixing Screws Included? | No |
| Standalone Fire Rating? | No — performance belongs to the complete tested or assessed lock and doorset arrangement |
| Standalone Smoke Rating? | No |
| Standalone Acoustic Rating? | No |
| Lock Type | Thickness | Strike Protection | Product Code |
|---|---|---|---|
| European sashlock / DIN lock | 1mm | Not included | INT/1/TH100 |
| Lock Options | Thickness Options | Strike Options | Total Variations |
|---|---|---|---|
| European sashlock / DIN lock | 1mm | Without strike | 1 |
The lock mask should only be selected where the supporting evidence permits:
Do not assume compatibility solely from the DIN description. Compare the mask with the lock and verify the complete fire-door specification.
One ordered item contains one lock-body protection kit.
One kit will normally be required for each compatible lock case, subject to the applicable doorset specification.
Any separately required strike or forend protection must be calculated and ordered independently.
Do not install the mask if it is:
The lock mask must be installed in accordance with the current lock-manufacturer instructions and the evidence for the complete fire-resisting doorset.
This product protects the lock-body location only. Confirm separately whether protection is required behind the forend, strike plate or other associated hardware.
Before installation, confirm:
Do not substitute a different lock, mask thickness or intumescent material without supporting evidence.
Lay the mask on a clean, dry surface and compare it with the lock case.
Confirm that:
Form the lock recess only to the dimensions permitted by the lock and doorset evidence.
The mortice should be:
Allow for the specified 1mm mask without creating an unnecessarily oversized mortice.
Remove all machining dust and loose material using a suitable brush or vacuum.
The surfaces receiving the adhesive-backed mask must be clean and dry.
Do not install the material over:
Position the mask around the lock case or within the mortice without removing the release liner.
Follow the orientation shown by the current product instructions or doorset detail.
Check that the mask:
Do not trim the mask unless this is expressly permitted by the supporting evidence.
Remove the adhesive release liner carefully without contaminating the adhesive surface.
Apply the mask in the required position and press it firmly into place.
Ensure that:
Insert the compatible lock carefully into the protected mortice.
Take care not to:
The lock should seat correctly without excessive force.
Align the lock forend with the door edge and install the fixings specified by the lock manufacturer and doorset evidence.
Tighten the fixings evenly so that:
This product does not include strike-plate protection.
Where the evidence requires additional protection, install the specified separate components behind:
Do not improvise these components from unsuitable materials.
Fit the approved handles, spindle, cylinder, escutcheons and other hardware in accordance with the lock and doorset instructions.
Ensure that no fixing damages or displaces the concealed intumescent mask.
Operate the lock and door several times.
Confirm that:
Verify that:
Inspect the lock as part of the routine fire-door inspection programme.
Check for:
Whenever the lock is removed or replaced, inspect and reinstate the specified intumescent protection before returning the door to service.
The Interdens DIN lock mask does not independently provide a fire-resistance period.
Performance depends on the complete approved doorset, compatible lock, mortice dimensions, intumescent protection, associated frame hardware, mechanical fixings and installation quality.
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