The invention relates to walls and roof coverings of industrial and civil buildings, in particular to a construction method applying
external wall insulation of
cement based
thistle boards. The invention is characterized in that the walls and roof coverings comprise
polyurethane foam insulation material, flexible anti-
cracking putty made of the same material, TOX nylon sleeve steel nails,
cement based
environmental protection thistle boards, grooves, alkali proof mesh cloth, flexible anti-
cracking putty, L-shaped grooves and tongues, weatherproof
silicone seal gum, cavities and facings. The
cement based
environmental protection thistle boards are processed to have L-shaped mortise-and-tenon joint structures in a factory, the TOX nylon sleeve steel nails are used for anchoring the cement based
environmental protection thistle boards and base courses, the cavities are reserved in the middle, then the
polyurethane foam insulation material is poured into the reserved cavities, so as to complete composite connection combining both the anchoring and bonding; location references are formed by each L-shaped mortise-and-tenon joint structure of two adjacent cement based environmental protection thistle boards, the flatness of the outer surface is also ensured, the L-shaped
tongue and groove tenon
abutment joint positions are coated with
foam rubber to be sealed, the flexible anti-
cracking putty 8 is applied to the preprocessed grooves with 1.5 to 2.0 mm depth and 50 to 80 mm width, the alkali proof mesh cloth 7 is pressed in the grooves, then the flexible anti-cracking putty 8 is applied, the grooves are levelled up by using the method of pressing the cloth once and applying the putty twice, the depressions of the holes of the TOX nylon sleeve steel nails are leveled up by flexible anti-cracking putty made of the same material, and then the facing is performed to the surface.