(3) Because of the high porosity of light weight insulating fire bricks, they cannot withstand excessive loads, and they must also avoid contact with molten metal, slag and high-temperature furnace dust;
(4) Lightweight light weight insulating fire bricks have low strength. When building with light weight insulating fire bricks, brick joints and expansion joints should be arranged correctly to avoid squeezing the masonry due to expansion. Light weight insulating fire bricks should not be subjected to strong mechanical vibration, impact and friction;
(5) The linear shrinkage after reheating of light weight insulating fire bricks is large, and the maximum use temperature should be 100℃ lower than the dry firing temperature, and must not exceed the allowable temperature;
(6) The difference between thermal insulation materials and heavy refractories is great, and the thermal shock resistance of light weight insulating fire brick is poor. When using light weight insulating fire brick to build the kiln lining, the temperature rise and fall speed should not be too fast, otherwise the lining will be cracked and damaged. For heat-insulating refractory bricks built on the outer layer of the lining, reinforcement measures must be taken. Such as reinforcement with furnace wall steel plate or metal rods.