The glass block is a unique architectural element which is compliant with the National Construction Code (NCC) fire-rating requirements and offers solutions for increased natural light, privacy, security and insulation.


Glass blocks and fire-rating

A glass block panel installed in a wall or floor is able to prevent the spread of flames and smoke for a period of 60 minutes or longer depending on the glass block used. To see our range of fire rating glass blocks, head to our fire rated glass blocks page.

Fire resistance classification 1530.4-1997 & 1530.4-2005 Fr 60/60- Integrity only
Prevents spread of smoke and fire for 60 minutes
Fr 90/90- Integrity only
Prevents spread of smoke and fire for 90 minutes
Fr 60/60/60 Integrity & insulation Prevents spread of smoke, fire and thermal radiation for 60 minutesFr 90/90/90 Integrity & insulation Prevents spread of smoke, fire and thermal radiation for 90 minutes
Glass block typeStandard & PegasusSeves BSH 20Seves 1960FSeves 1990F
Size190 x 190 x 80190 x 190 x 80190 x 190 x 160190 x 190 x 160
Maximum glazed area per elements9m²9m²9m²9m²
Maximum height3.5m3.5m6m6m
Maximum width6m6m6m6m
Thickness of glass block wall80mm80mm160mm160mm
Certificates & CSIRO opinionsIbmb 3215/1507 CSIRO fco-2115 Ibmb 3571/2980 CSIRO fco-1833Ibmb 3187/1237 CSIRO fco-1835 Ibmb 3422/2416 CSIRO fco-1835

Residential buildings

  • The NCC requires 60 minute fire-rating for external walls and windows less than 900mm from a boundary
  • In a number of states windows within 3 metres of a brush fence must be fire- rated
  • If there are multiple buildings on the same property, an external wall less than 1800mm from the next building is required to be constructed with fire-rated materials.

 Commercial buildings

  • The various classes of commercial buildings require different levels of fire-rating. The maximum achievable fire-rating for glass blocks in vertical walls is 90/90/90
  • For horizontal structures such as floor paving, the maximum achievable fire-rating for glass blocks is 120/120/90

Fire resistance level (FRL)

The FRL consists of 3 ratings in minutes: structural adequacy/integrity/insulation.

  • Structural adequacy –  the ability of the structure to withstand collapse within the prescribed period
  • Integrity  –   the ability to resist the passage of flames and smoke
  • Insulation  –  the ability of the surface not exposed to the fire to maintain a temperature below the limits specified in AS 1530.4

The NCC states that windows or glass panels in the above external walls are required to be protected with a fire resistance level of   /60/    i.e.  the ability to resist the passage of flames and smoke for 60 minutes.