Foamed Glass: Use and Costs

In the field of thermal and moisture insulation, it is always worth considering new technologies, even if proven solutions are at your fingertips. One of such innovative insulating materials is foamed glass. It is used in the form of lumps or slabs in various areas of construction. Here’s where you should consider using foamed glass and what it costs.

In the form of lumps, foamed glass, also known as foam glass, is often used to insulate foundation slabs. However, in the form of slabs, it works perfectly on flat roofs with an inverted layer arrangement. What makes foamed glass a material worth considering? First of all, it meets all the key criteria that thermal and moisture insulation should meet in these areas.

Applications of foamed glass

Thanks to its non-absorption properties, foamed glass can be successfully used as an insulation layer for foundation slabs, even on wet soil. An important element is that the insulation is continuous and surrounds the foundation on all sides, not only from the bottom. The foamed glass band “protrudes” beyond the outline, usually by 60 cm to 100 cm, depending on the geographical location of the building. Thanks to this, the foundation has no contact with the ground at any point, which eliminates thermal bridges, protects the foundation against the effects of ground freezing and is also a practical form of permanent formwork.

Foamed glass – insulation costs

If we compare the costs per 1 m3 of insulating materials used to insulate foundation slabs, foam glass is not the most expensive. The price for 1 m3 ranges from PLN 240 to PLN 300. In comparison, polystyrene costs from PLN 240 to PLN 338, and extruded polystyrene from PLN 439 to PLN 502. Per 1 m2, the standard insulation is 24 cm thick polystyrene (cost PLN 69/m2) or 20 cm thick extruded polystyrene (cost PLN 94/m2). In turn, foamed glass, due to its low thermal conductivity coefficient, requires a layer about 50 cm thick. This translates into a cost of PLN 135/m2.

To compare the costs of foamed glass insulation with other solutions, it is worth taking into account the additional materials necessary for their use. In the case of polystyrene insulation, it is necessary to add the cost of the drainage layer. It can be made of aggregate at least 15 cm thick, sand bed 10 cm thick (without equipment rental costs) and a layer of moisture insulation made of 0.6 mm thick foil – which means an additional PLN 40/m2. However, when choosing extruded polystyrene, you only need to take into account the cost of sand bedding – PLN 16/m2. However, in the case of foamed glass insulation, you only need to add the cost of geotextile, which is approximately PLN 3/m2.


Although the prices of individual solutions vary, in the end the differences are not that big. The cost of insulation made of polystyrene is approximately PLN 109/m2, for extruded polystyrene – approximately PLN 100/m2, and for foam glass – approximately PLN 138/m2. Therefore, it is worth carefully considering your needs and financial possibilities in the context of choosing an insulating material for a specific construction project.

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