Weight of polystyrene foam and its influence on the characteristics

Dependence of weight and characteristics of polystyrene insulation.

Styrofoam and its weight. How do characteristics and weight depend?
It is interesting that the thermal conductivity, depending on the brand is not very different and for this indicator polystyrene is one of the best insulation.
So, the weight and, accordingly, the brand affects the working conditions, the load on the insulation, and the durability of the material. Dense and especially dense, for example PS20 or PS30, can withstand enormous pressure and temperature changes. But do not ignore the brand of low density, because they are inexpensive. Without load or with no significant impact of such polystyrene will serve in the walls or floors for at least 50 years.  At the same time, relative to other heaters, the weight of this is very small. That ultimately reduces the pressure on the structure and affects the cost of the structure as a whole.
And some more information about the weight and characteristics.

In contrast to the old GOST, where the same polystyrene was called abbreviated PSB-C and where the marking indicated the maximum density or weight of the product. In the new standard GOST 15588-2014, polystyrene is denoted by PPP and the marking indicates the minimum density of the product. What gives? This gives the consumer a clear understanding of the minimum weight density that he should get for his money. At a lower weight so I need to reduce brand and the price. In the old Guest, for example, was a brand of PSB-S-25. 25 is the maximum density, and the minimum specified density of this brand was 15 kg/m3.Of course, the products were shipped to the consumer according to the minimum bar. Even in the new standard there was a more detailed division by brands and their density. Brands became more, respectively expanded and the choice for builders.
Discounts on bulk purchases.

Characteristics of expanded polystyrene:

    Brand: EPS13 ISO
    Sheet size: 1000x1000x150 mm
    Price per piece: 320 rubles
    GOST: 15588-2014
    Water-resistant: YES
    The availability of Fire safety certificates: YES
    The existence of a certificate of SEZ: YES
    Availability of ISO 9001 certificates: YES
    Styrofoam should be protected from prolonged exposure to the sun!