Introduction  Due to the natural properties of steel, it is an ideal material for fire rated applications allowing the specifier to use steel windows throughout the project and not have to change section profiles for windows and doors requiring a fire-rating.  We specify below the glass types, frame types and glazing methods that we adopt to meet the specified fire rating criteria.  These have been formulated in accordance with assessments C118328 and C118420 carried out by independent assessors Warrington Fire Research.  The full 22-page report can be produced upon request.  Fire rating is not available for the EB14 and EB24 ranges of steel windows.
 
Frame specification  With the exception of glazing system and fixings, all specifications for window frames are as per window range product sheets.
 
Fixing fire-rated windows  When fixing windows requiring a 30 minute integrity rating, window perimeter fixings must be no more than 150mm from corners and maximum 450mm centre to centre.  When fixing windows rated for 60 minutes integrity, fixings must be no more than 250mm centre to centre.  Fixings should be made through the frame under the glass and be affixed to good structural openings of either brick, block, concrete masonry or steelwork which should have both stability and integrity greater than the window frame.  Should lugs be required to fix the windows - these should be at least 25mm wide x 2mm thick steel.
 
Glazing Methods    All fire-resisting glazing is to be set onto non-combustible setting blocks and is to be secured by cold-formed 0.6mm thick steel channel beads which are snapped over steel mushroom head studs and are finished at corners with corner cover clips.  All studs placed at maximum 75mm from corners and maximum 300mm centres.  Ceramic or mineral fibre tape to be placed either side of glass edge and is to be capped with intumescent silicone sealant.
 
Maximum pane sizes  The maximum recommended pane size for fire-rated glazing is 1.53 square metres (subject to glass type, available stock sizes and limitations).  The maximum pane height is to be 1696mm when the width does not exceed 900mm.  The maximum pane width is to be 1450mm when the height does not exceed 1053mm.  At the most favourable length to height ratio of 1:1, the maximum height/width is 1237mm.  No limitations on length to height ratio as long as maximum area is not exceeded.
 
Glass specifications  Below are the most popular, cost efficient and readily available fire rated glass specifications.

  SMW
 

  W20
 

  W40