Glass specification explained: double, triple and laminated glass Back to all blogs | Glazing Vision Europe | Tutorials When buying a glass roof access hatch or rooflight, you want the highest glass quality. Of course including the best insulation values to comply with your project’s standards. In this article you can read more about the difference between our standard glass, laminated glass and walkon glass. Standard double glass: tempered and insulation value comparable with HR++ Our standard double glass has excellent insulating properties, which are comparable with HR ++. The properties listed: HST tempered glass is safer The glass is ‘Heat Strength Toughened’, which means that it was tempered by means of thermal treatment. This gives the glass its special properties: it is extra strong, resistant to larger temperature differences and safer. Just like glass in for example car windows or bus stops, this glass will break up into small pieces. Argon-filled cavity The cavity between the glass layers is filled with argon. This noble gas ensures better insulation than dry air. Special low E coating for better thermal efficiency The inner sheet of the glass has an invisible low E coating, that ensures less loss of warmth. This means that the warmth stays out in the summer and in during the winter, while the light transmission remains the same. Triple glass: improves the insulation value HR+++ If you want even better insulation, you can choose triple glass. This consists of three glass sheets with two argon-filled cavities. The insulation value is comparable with HR +++. This way you can achieve the standards required for the passive home standard. The loss of warmth, expressed in U value must in that case be below 0.8 W/m2K). The U-value of glass is however not only dependent on the type of glass, but also on the glass size. Narrower glass sheets, for instance, have a higher U-value than wider glass sheets. Laminated glass: multi-layered glass Laminated or multi-layered glass is also called safety glass. In this case, the glass is composed of individual glass sheets with transparent foil (PVB) in between. In case the glass breaks, the foil holds the glass together, preventing large holes. The structure of laminated glass is determined by the thickness of the glass sheets and the foil in between. Multiple layers of foil can be applied. The maximum size of laminated glass is smaller than that of double and triple glass: where the maximum length of a horizontal glass panel for double and triple glass is 4,150 mm is, for most types of laminated glass, it is 3,100 mm. Opal glass: laminated by use of a white interlayer Would you like to apply glass on top of a bathroom or other space where you want daylight to enter, but preferably no viewing? We can supply glass with a white interlayer. This provides privacy while the light transmission remains very high Which type of glass should I use? The standards for the use of glass differ per country as well as per application. Glazing Vision will be happy to advise you about which type of glass is most suitable for your situation.