How much does glass weigh per square metre?

When specifying glass for a project, it's important to calculate the weight. To achieve this, you need the following equation:
Weight (kg) = Length (m) × Width (m) x Thickness (mm) × 2.5This applies to all types of glass.

Step-by-step method

1. Get the length, width and thickness of the glass panel. 
2. Convert the units. Make sure the length and width are in metres (m) and the thickness in millimetres (mm).
3. Calculate the area. Multiply the length (m) by width (m) to get the area in square metres (m²).
4. Multiply the area (m²) by the thickness (mm).
5. Calculate the weight. Multiply the result from step four by 2.5 to find the weight in kilogrammes (kg).
   
   

Example

Let's say you have a glass panel that's 1.7 metres long, 0.5 metres wide and 12 millimetres thick.

Calculate the area: 1.7m x 0.5m = 0.85m²

Multiply area by thickness: 0.85m² x 12mm = 10.2

Calculate the weight:  10.2 x 2.5 = 25.5 kg

How much do different kinds of glass weigh?

 Annealed glass usually weighs the same as toughened glass. This is because toughened glass (also known as "tempered glass") is processed using heat. This doesn't add or remove any material from the finished glass unit.
Laminated glass is generally heavier than toughened glass of the same size. This is because it consists of two (or more) layers and a plastic interlayer. The interlayer will add a slight weight per layer which will be reflected in the overall weight.

Double-glazed and triple-glazed units have additional thickness thanks to the spacer and sealant. A 4mm double-glazed unit is roughly 22 kg/m² as opposed to 20 kg/m² for toughened glass. Triple glazing is about 50% heavier than double glazing.

Why is the weight of glass important?

The weight of glass is important for a number of reasons. These include:

1. Safety

Knowing the weight of glass is essential information when planning manual handling procedures and carrying out risk assessments.
Without a precise calculation, construction teams won't know how many people are needed for a manual lift or whether specialised handling equipment is required.

2. Structural integrity

Architects and engineers need to make sure supporting glass frameworks can bear the weight of the structure itself (the so-called "dead load"). An incorrect calculation can compromise the structural integrity of the whole.



3. Logistics

The weight of glass affects the mode of transport used to carry it, along with fuel costs and the maximum load capacity of delivery vehicles.

4. Compliance with building regulations

By taking care over weight calculations, suppliers, construction companies and other parties can avoid costly redesigns and ensure that the overall project meets industry regulations. 
Are you looking for high-quality toughened or laminated glass, cut to size ? Don't hesitate to contact ToughGlaze for a quick, competitive quote – or explore our range of products online.