Glass, much like water, can be deceptively heavy for its physical size. Glass weight plays a big factor in determining what type of hardware and frame type are required for our aluminium windows and doors. It also plays a role in determining the number of people required to lift glass into place or if a crane is required.
This is the basic formula used to calculate the weight of glass: Height (m) x Width (m) x Glass Thickness (mm) x 2.5 = Glass Weight (kg)
Note: The height and width should be in meters and the glass thickness should be in millimetres. Let’s use this formula in an example.
So for example, a piece of single glazed glass which is 6mm thick and has a height of 1.2m and width of 1.8m will have a glass weight of 32.4kg (1.2 x 1.8 x 6 x 2.5 = 32.4kg).
If you are trying to figure out the weight of a double glazed unit (sometimes known as an insulated glass unit or IGU) the same formula applies, but all you need to do is add the glass thickness on each side together. So, using the same size example as previously, a double glazed unit with 4mm / airspace / 4mm glass measuring 1.2 x 1.8 would calculate as follows - 1.2 x 1.8 x (4+4) x 2.5 = 43.2kg.
Most pieces of glass in an average home will weigh under 100kg and so no crane hire or heavy lifting equipment is required - however, if you’re after a large picture window then it can be quite a different story.
With very large panes of glass, we always have to ensure that we adhere to Australian Standard AS1288 (you can read more about that here), so sometimes that can mean needing to use a very thick glass type such as 8mm / airspace / 8mm.
If for example, your window glass measures 2.7m by 3.2m, then the glass would weigh 345.6kg (2.7 x 3.2 x 1 x 2.5 = 345.6kg) and so would require crane hire to help install the glass in place.
At Nuline, we only use commercial grade framing and hardware which are specifically designed for large and heavy pieces of glass. As such, lifting large and heavy pieces of glass has become a standard procedure for us. Please see below for some of our projects featuring large glass:
Canterbury
Newport
