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Intumescent fire and smoke grilles

Product 34


Automated, intumescent lined shutter grille which can be connected to fire alarm systems

Not available to purchase online.

We need to ask you a few more questions and ensure this is the suitable product for your needs.

To order please call us on +44 (0) 1 304 842 555

£0.00 ex. Vat


Intumescent Grille

The Envirograf® Fire and Smoke Grilles offer full protection against smoke as well as fire for openings in walls, ceilings, and also fire doors. Installed at the entry point of ventilation ducting. In the event of a fire, the intumescent expands and the grilles automatically seal off.

Grilles placed over ventilation ducting don’t require an intumescent plate. Fires and smoke grilles compartmentalize and prevent fire and smoke from spreading as intumescent expands to create a fire barrier. Smoke inhalation is a leading cause of fatalities where fires occur within households and buildings.

Grilles are designed with open slots which allow viewing, or also louvered for non-viewing.

  • Available with a variety of resetting options, including manual, automatic, thermal as well as memory spring.
  • Furthermore, a non-electrical grille containing a memory spring device operates in the temperature range of 50oC to 65oC, closing the shutter in under 60 seconds.
  • Available in different sizes and also made to order.

Wired into existing fire/smoke alarm systems or into an Envirograf control unit. Tested to BS476 Part 20 (1987), achieving 66 minutes of integrity. Automatic closure grilles tested to BS476 Parts 20 & 22, achieving 73 minutes of fire protection.

Our patented range of passive fire ventilation products meet Document B of UK Building Regulations and tested to European Standards.


– Provides up to 73 minutes integrity- Can be wired into an existing 24V fire/smoke alarm system, or into an Envirograf® AC mains to 24V control unit. This unit can be used to control up to 3 TJ grilles
– Four resetting options are available for the grille:
(A) Manual re-set (by hand, with a screwdriver or knife) with a permanent loading of 125mA 24V
(B) An automatic re-set grille with a permanent loading of 125mA, with a re-set loading of 6A 24V for a period of 1 second
(C) A non-electrical grille containing a thermal breaker that automatically activates at 70ºC, moving the shutter to the closed position
(D) A non-electrical grille containing a memory spring device that operates in the temperature range 50ºC to 65ºC, closing the shutter to fire and smoke in about 47 seconds

Application Instructions

The TJ grille can be fitted into doors, walls and partitions. Cut a hole in the door or wall to the sizes as
quoted in the Order References – other sizes can be made to suit your opening (price quoted on request)
The grille is fitted into the aperture and screwed to the wall, door or partition. The intumescent plate is screwed to the opposite side of the door, wall or partition to the main unit. This intumescent plate need not be fitted if the main unit is fitted in ventilation ducting. The plates can be supplied with open slots which allow viewing or louvered for non-viewing.

Order References / Sizes



This type is reset by pushing the internal plate back to its original position by means of pen or screwdriver. The plate is held open by an electro-magnet 24V 125mA.


This type resets itself and has a permanent loading of 24V 125mA, with the solenoid to open the grille taking 24V 8A for 1 second.


This type closes when the fire gets near the grille. At 55°C, a thermal link breaks and closes the shutter.


This type closes when the fire gets near the grille. At 50°C to 65°C, the grille will close, but the spring returns to the open position after the fire is over.


The grilles are supplied to be open normally and close up in a fire. However, all of these grille types can be made to be closed normally and to open in the event of a fire.

 Manual Reset and Automatic Reset grille options can be wired to a 24V alarm system. Alternatively, an Envirograf® mains to 24V control unit can be used to control up to 8 manual reset grilles or 3 automatic reset grilles. The control units have N O (normally open) and N C (normally closed) contacts to wire to the existing fire alarm or optional smoke detector.



Internal Hole Size                External Size
Ref Height x Width              Height x Width

NTJ1             140 x 280mm                    200 x 340mm
NTJ2            240 x 280mm                    300 x 340mm
NTJ3            190 x 305mm                    250 x 365mm
NTJ4            270 x 305mm                    325 x 365mm
NTJ5            340 x 380mm                   400 x 440mm

References shown for manual reset grilles only. Other grilles made to order.

Without a suffix  –  Manual Reset Type

Add suffix /A for auto reset grille
Add suffix /MS for memory spring grille
Add suffix /TL for thermal break grille


TJ Grilles are available with the following optional extras:
CTJ1: A control unit supplying up to 3 grilles (2 if the grilles are larger than 400x400mm and 1 if over 500x500mm)) with a smoke detector circuit with N/O or N/C terminals for AC mains to 24V supply
SG/S: Smoke detector and base for use with the CTJ1 Control Unit
SG/CB: A control unit with a battery back-up and charger to keep the grille open in a 24 voltpower failure

Standard finish is brown or white.

Other colours may be available.

State colour requirements clearly when ordering.

Other sizes can be made to special order. Special custom sizes are non-returnable.