Foam is the best insulation particularly when compared the other insulation both in the perspective of qualification and using life span. Usually, foam would not absorb water but as foam has low melting point, so that it would be able the change in shape when contact with high temperature. But when we use foam for the general roof of houses, offices, and Industrial plants, it would be regarded as the best insulation as when working on that area, the temperature is not high for that level, except only when installed in the sunshiny area or the area that high temperature of more than 100oC which would resulting in the absence of shape retention capability when has none of internal frame that use to attach. However. type of foam that we use currently has varied and able to classified in several classes, but the most popular class of foam that use in the work of construction has at least 4 classes described as follows:
1) P.U.FOAM(Polyurethane Foam)
Polyurethane Foam is CHFC-141b substrate that spray out in the appearance of foam, wich has both classes of solid mold by injection molding foam or spray on the surface as rigid foam is one of the materials that is very low rate of heat conducted condition(K-Factor) as it is produced of HCFC-141b Substrate that has heat conducted condition lower than in the air,. Mostly, for the manufacturing of general insulation must cover with the material that has the property of fire retardant, but P.U.FOAM is compounded with inflammable substrate in itself. P.U.FOAM has the structure of close cell so that made it capable for better resistivity for humidity in eithet cold storage or water leakage on the roof better than other kinds of insulation.
4) P.E.FOAM (Polyethylene Foam)
Ethylene is the insulation that produced from ready-made P.E.foam sheet manufactured with low density polyethylene substrate(LDPE). The main qualification is that is able to recuce heat and noises coming from external area of building. Moreover, it is also use to install before roofed by using together with coherent material (gum) by extruded and pressed with selected roof. This kind of insulation has the value of heat resistivity or K-Factor approximate with glass fibre and cellulose fibre at equal level of bulk density