Two kinds of precast products (a combined precast and a separated precast) made of rock wool as a base material were developed as an improved perspirable roof to strengthen nonflammability. Fig.1 shows the combined precast product (10mm in thickness) and the separated precast product(5mm in thickness). The combined precasting consists of three layers, the arrangement is as follows; nonwoven fabric in the first layer (outside layer) for surface protection, rock wool and thermal bond fiber in the 2nd layer for ultraviolet rays penetration prevention, and thermo-sensitive hydrogel, rock wool and thermal bond fiber in the 3rd layer in three layer structure. (It is called sample (1).) On the other hand, the separated precasting assumes to be a double layer system, which consists of the 1st layer and the 3rd layer of the combined type, eliminating the 2nd layer. (sample (2)) Both products were able to clear the fire test as a nonflammable material by the cone calorimeter examination.

1)Nonwoven fabric .( 2)Rock wool+Thermal bond fiber +Hydrogel Steel plate 0.2 Foam poly-styrene 50 Steel plate 0.2

Perspirable Roof Material

Perspirable Roof Material

10,

50

Fig. 1(a) Perspirable roof (Combined precast product) Fig.1(b) Perspirable roof (Separated precast product)