DOORS, WINDOWS & GLAZING
STEAL A MARCH WITH STEEL
036 ATB
Steel windows offer a wide variety of aesthetic and performance benefits over comparable alternatives. Here, market leader Crittall answers some common questions relating to the specification of the product. Strength, security, and maintenance - how do steel framed windows measure up compared with other materials? Steel is inherently the strongest frame material for windows and doors. It is three times stronger than aluminium for example. But this strength is combined with elegance. The profile (sightline) of a steel window is much less than that of its aluminium or uPVC counterparts. The slender appearance allows, frame for frame, a greater surface area for the glazing and, indeed, larger expanses of glass can be achieved while retaining an aesthetic appearance. The steel frames are almost virtually maintenance free. They are hot dip galvanised and finished with a factory applied Duralife polyester powder coating in accordance with BS EN13438. Products thus protected have a life expectancy in excess of 60 years. The strength of the material, and multi-point locking also greatly enhance the security of the buildings in which they are installed.
Tell me more about thermal performance. Isn’t steel cold? Window frames made from traditional rolled steel are energy efficient incorporating high performance weatherseals, insulating double or triple glazing and narrow sightlines that enhance U values and reduce energy consumption. A T60 thermally broken window features an advanced high-density polyurethane isolator as a thermal barrier. This, together with housing high performance double or triple glazing up to 45mm wide, ensures the system surpasses the requirements of current regulations offering overall U values as low as 0.8 W/m²/K. Market-leading weather-tightness performance has been tested to European and ASTM standards. Alternatively, Ultra insulating glass units use suspended film technology in a double-glazed unit to convert it to provide triple-glazed performance. Ultra IG’s innovative design results in a thinner and lighter construction compared to traditional triple glazing, as well as being superior in performance, offering U-values as low as 0.4 W/m²/K in a double glass unit, without increasing glazing thickness or weight.
36
