Size guide for Clearview secondary glazing

The table below gives an overview of recommended minimum and maximum secondary glazed unit sizes.

Understanding Secondary Glazing Sizes: A Comprehensive Guide

Unit production viability is subject to Width x Hight x Panel Size x Glass Weight ratios (& spring size availability with Vertical Sliders)

If the online quote system will not calculate a quote, it will advise if the unit is too big x small or a panel is to large, this will either confirm the size is not possible or automatically upgrade the glass to a viable option, if it just won’t calculate, you will need to change the specification. See Why Won’t My Quote Calculate.

See the specific product page, in the products dropdown menu, or email details of your query. You’ll find the glass weight calculation formula here.

NOTE: The Maximum sizes are based on the maximum individual span in width or height, not combined. The weight will determine if the panel size can be produced. i.e. if the maximum size detailed for a unit is 4900 x 2700, if using an 8.8mm glass, you may be able to have the width at 4900, but not the height at 2700 and vice versa in height and width. 

Units will be supplied fully assembled and pre-glazed as standard, unless, both the unit width and height are both over 1800mm these units will be supplied flat packed. Units can be supplied flat-packed on request, there is a surcharge for this option.

Maximum Unit Criteria within above limits

  • Lift Out:  max panel weight 65kgs
  • Horizontal Sliders: Max individual panel width 4mm glass 1200mm – Units heights over 2000mm, min sub-frame 62x 16mm with HD Interlocker – max panel weight 80kgs
  • Vertical Sliders: Max individual Panel height 1800mm, max panel weight 48kgs (8mm glass minimum for very small units)
  • Hinged Unit SL 65kgs / Hinge Unit HD 100kgs
  • Inserts 45kgs


Maximum width is determined by panel weight and height, it may not be possible to make some units in the maximum width/height specified and will need to clarified at point of enquiry.

  1. Glass weight and do not exceed the maximum panel weight.
  2. Maximum area for 4mm glass is 1.6m2. If panel size exceeds this, allow for 6mm toughened glass. Maximum area for 6mm glass is 3.0m2. If panel size exceeds this, allow for 6.4mm laminated glass.
  3. Flyscreens: maximum size 1200mm in one direction

If you need any more assistance, email us with sizes of the required unit.

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