One of the main parameters of EPS is the coefficient of thermal conductivity, ie lambda, which is in the range from 0.030 to 0.045 W / (m * K) and determines the ability of polystyrene to conduct heat. It is important for all types of polystyrene, both for warming of front walls, and for warming of a floor or base walls.
Under the same conditions, more heat will flow through the polystyrene with a higher thermal conductivity. Therefore, polystyrene with low lambda and relatively small thickness can insulate a building better than thicker polystyrene with a higher λD. If possible, choose polystyrene with the lowest lambda value. However, in addition to the thermal conductivity, other parameters are also important (tensile strength, flexural strength and water absorption).
Facade insulation boards must have a tested tensile strength perpendicular to the end surfaces – TR. The value of TR cannot be lower than 80 kPa, the most optimal and recommended indicator is 100 kPa.
Another parameter that characterizes polystyrene is the compressive strength at 10% linear deformation, kPa. This is the ratio of the compressive strength to the surface of the polystyrene plate. Therefore it is necessary to choose polystyrene with high value of CS that guarantees high resistance to compression.
In places where the insulation withstands high mechanical loads, ie in the foundation slab, floor and flat roof, the parameter BS, ie flexural strength, is important. Regarding the bending strength, the numerical part in the designation shows the minimum value of the loading bend in kPa.
When choosing polystyrene, consider not only the price but also its density. The weight of polystyrene indicates its quality and meets all the necessary parameters for it. Not all polystyrene manufacturers indicate the density of the product on the packaging.
Eurobud places legible information about the product’s parameters on each package. They are presented in the form of a table showing the main properties, such as the minimum density of the product in kg / m³, compressive strength (CS), flexural strength (BS), tensile strength (TR) and the declared thermal conductivity indicated by the symbol λD.
