1. Thermal insulation performance:
The insulation properties of EPS and XPS with the same thickness are gradually improved. EPS was 0.041, XPS was 0.030. Therefore, XPS board is thinner than EPS board under the same insulation effect, but XPS board is more expensive than EPS board. If you consider the workmanship and height of the building, XPS per square meter is actually more expensive than EPS.
For thermal insulation, the main concern is thermal inertia indicator D, which is proportional to the thermal storage coefficient. However, as far as the whole system is concerned, the heat storage capacity of 200 mm concrete is enough, and the addition of outer insulation layer fully meets the requirements of energy saving.
The strength shown here should be tensile strength, and the bulk density of polystyrene board has a certain relationship with tensile strength. Generally, the stacking density of EPS is about 110-120kpa at 18kg / m3 and 140kpa at 20kg / m3. XPS has a bulk density of 25kg to 45kg and a strength of 150kPa to 700KPA or higher. (the premise is to meet the thermal conductivity of about 0.03).
XPS board strength is 200kpa-250kpa, most domestic manufacturers XPS board is basically 100 ~ 200KPa, EPS board is less than 100KPA, in more and more rich facade decoration and typhoon often appear in coastal areas, the strength is very important, especially for some exterior wall brick or high-rise building, the two boards need to be reinforced or fixed with fixed auxiliary equipment. The wire drawing of ceramic tile should be greater than 400kPa. Even XPS can't afford it. The solution is to fix the wire mesh to the base by expanding bolts. This can spread the tensile stress into the three-dimensional space, so as long as the anchor is properly anchored, the pull-out damage must be compounded. The anti cracking mortar layer of steel mesh is not a big problem.
Compared with EPS, XPS board has higher strength. However, due to the brittleness of EPS board, when the bonding area is large, the possibility of cracks in the coating is very high. Surface layer. Flexibility is a matter of wood properties. In the case of facial skin, perceptual knowledge is usually applied to polystyrene board, and then the bending degree of polystyrene board will not break. When flexible, it bends several times. It won't crack. Similar to the ductility index of waterproof materials. However, for the material itself, flexible EPS is superior to XPS.
3. Weather resistance:
Weatherability refers to the ability of the insulation system to adapt to external changes, and a series of quality related issues, such as the overall stability of the system and the change of insulation effect under different climatic conditions. Weather resistance is a very important index of insulation system.
Because EPS board has higher water absorption than XPS, its weather resistance is not as good as XPS system. However, the ductility of EPS is better than that of XPS, and some defects can be overcome. However, as far as the system is concerned, the outer layer of the thin plastering system itself has a certain waterproof capacity. In addition to the construction process, the waterproof performance of both systems is very good. The contact between the rain and the wall is vertical. As long as the mortar on the surface does not crack, waterproof is not a problem.
In addition, wind pressure resistance is also an important factor in weather resistance, because the more cavities the system has, the worse the wind pressure resistance is. Therefore, the focus will be on the size of the entire bonding area between the insulation system and the base course. There is no problem with this XPS system and EPS system.
4. Air permeability:
Ventilation and water absorption are two problems! There is a big difference in the size of air molecules and water molecules! Of course, there's talk about air permeability and air tightness. Experiments can illustrate this. In Shenzhen, for example. Put the biscuits outside. You don't have to add water to the biscuit. During the day, the biscuit softens because it absorbs moisture, which is water in the air, not liquid water.
In the insulation system, no product dares to claim that its product has good air permeability, good thermal conductivity, good waterproof performance and no water absorption. Because these indexes are contradictory, we should pay attention to the permeability of wet water after construction.