Intumescent Seals is a division of Dixon International Group Limited


THERM-A-GLAZE 45 installed in a fire door

THERM-A-GLAZE 45 is a low pressure intumescent strip material which has been developed for glazing applications to satisfy the demand for a dry glazing system. The degree of expansion is moderate to give more resistance to erosion which is particularly beneficial in glazing applications.


THERM-A-GLAZE 45 has been developed to provide excellent sealing properties combined with the benefit of a flexible strip of intumescent material. It is particularly useful in cases where there is a possibility of localized flaming due to combustible products since it generates fire retardant gases during expansion.


THERM-A-GLAZE 45 intumescent strip is supplied at 10mm x 2mm & 15mm x 2mm as standard. It is a dry glazing material with a self adhesive backing to allow rapid and easy installation in glazed apertures. The material can be cut with scissors or a sharp knife so is easy to fit to glazing beads. THERM-A-GLAZE 45 has been very successful as a glazing seal in 30 minutes applications for both doors and timber screens.


THERM-A-GLAZE 45 is a flexible phosphate based intumescent product giving an approximate ten fold increase in volume when exposed to heat. Its activation temperature is around 180ÂșC. THERM-A-GLAZE 45 is supplied in a light oak colour as standard and requires no additional surface protection because of its resistance to both atmospheric moisture and carbon dioxide. The material may be decorated with a wide range of conventional finishes if desired without impairing performance. Other colours are available to special order.

  • 1. Glass
  • 2. THERM-A-GLAZE 45 glazing system (10 x 2mm)
  • 3. Softwood or hardwood glazing beads (min. density 460 kg/m3) 20mm wide by 15mm high, may be chamfered by approximately 20° or square, bolection return optional
  • 4. Non-combustible/hardwood setting blocks
  • 5. No.8 Screws or steel pins, 38mm long at 200mm centres
  • 6. Nominally 44mm thick FD30 door leaf or thicker if required to accommodate beads and glass at the required dimensions


THERM-A-GLAZE 45 colour swatch

THERM-A-GLAZE 45 is supplied in light oak as standard but other colours can be supplied to order:*

Nominal sizes are available in the following dimensions:

  • 10 mm x 2 mm
  • 15 mm x 2 mm

And in standard lengths of 1050 mm or 2100 mm.

Lengths of up to 3000 mm are available on request.

* Colours may vary slightly between examples illustrated in print, online and actual examples - which will depend upon lighting conditions in situ.

Test Evidence

THERM-A-GLAZE 45 has been successfully tested as a component of various door sets and glazed screens to meet the fire resistance requirements of BS476:Part 20 & 22. It has also been certified to the more exacting requirements of Certifire. See Intumescent Seals certificate CF 284 on for details. It is currently being evaluated to the requirements of BS EN 1634-1.

Copies of test reports and assessment evidence are available on request.

THERM-A-GLAZE 45 Certifire certified product IFSA and Certifire logo

Related Products

Improved glazing performance may be obtained by combining THERM-A-GLAZE 45 with other intumescent products in certain circumstances. Contact our Technical Department for further information.

Please contact our Technical Department for further advice.