The plastic material of EPS and XPS are both derivatives of PS—Polystyrene. They have similarities and also have differences in some aspects.

No. 1 Thermal insulation
The thermal insulation property of XPS board is higher than the EPS board of the same thickness. Therefore, to reach the same thermal insulation effect, the XPS board could be made thinner than the EPS board, but XPS board is more expensive than the EPS board.

XPS board

No. 2 Tensile strength
The tensile strength of polystyrene board has absolute relationship with its bulk density. The EPS board with the bulk density of 18 Kg/m³ has tensile strength of 110-120KPa, and 20 Kg/m³ corresponding to 140KPa. And the bulk density of XPS is from 25 Kg/m³to 45 Kg/m³, and accordingly the tensile strength is between 150-700KPa or higher.

EPS/XPS thermal insulation construction

EPS board has a comparatively higher water absorption than XPS boards, so its weather resistance is weaker than XPS, but the better ductility of EPS board can make up some shortcomings. And the plastering adhesive over the system also has waterproof capacity. As long as the surface layer keeps complete, there is no problem in waterproof in both EPS and XPS thermal insulation systems.

No. 4 Bond strength
The bond strength of the thin plaster system will directly affect the use of foam boards. EPS board has a lower bond strength, and is easy to be damaged, while XPS is much stronger than EPS in this aspect and can make the system more assuring.

thermal insulation system

In a word, both EPS and XPS are widely applied in the thermal insulation systems. Although they are non-degradable plastic materials, they can be recycled by foam recycling machines. GreenMax provides Polystyrene Compactor and Foam Densifier that can deal with both EPS and XPS. Through recycling, the waste EPS and XPS boards can be regenerated rather than polluting the environment.