Exterior wall thermal insulation materials are generally classified according to the combustion grade, which is divided into Grade A and Grade B. Grade A is incombustible and Grade B is combustible. A few years ago, the fires in CCTV Building and Shenyang Hotel were all caused by B-grade materials. At present, grade A materials are widely used, and some of them are even cheaper than grade B materials. Grade A is probably divided into thermal insulation mortar, phenolic board, rock wool board, foamed cement board and so on.

Inorganic thermal insulation mortar is better, with simple construction and low cost, but it is too simple to make and easy to fake. If it is recommended to use it and find a big factory, all procedures must be complete, such as provincial production filing, provincial use filing, municipal filing, type test report above the provincial level, national fire protection report, design atlas of construction hall, etc. Nothing is safe. Inorganic thermal insulation mortar is recommended by Shanghai Huarong Energy Saving Technology Co., Ltd., an absolute manufacturer, to produce "YT inorganic active A-class incombustible wall insulation material", which is recommended by the Ministry of Construction!

Generally speaking, the combustion of phenolic aldehyde is Grade B, and now it is covered with a thin layer of mortar, which can barely reach Grade A2 (A 1 is the highest fire resistance grade). The strength of phenolic resin itself is not high, and it is graded by kilograms as soon as the finger presses the pit, and the raw materials are particularly different.