Method for applying a spalling prevention layer

Abstract

The present invention aims to provide a method for constructing a spalling prevention layer that simplifies the work process compared to conventional methods and can form a spalling prevention layer with sufficient strength and elongation at fracture. [Solution] A method for applying a peeling prevention layer, comprising a step of forming a peeling prevention layer by applying a urethane-based composition to the exterior wall of a building and curing it, wherein the urethane-based composition contains a urethane prepolymer having isocyanate groups and a filler, and the urethane prepolymer is formed from a polyisocyanate compound having multiple isocyanate groups per molecule and a polyol containing butanediol and polyoxyalkylene polyol, and the molar equivalent ratio of butanediol to polyoxyalkylene polyol (butanediol:polyoxyalkylene polyol) is 60:40 to 75:25.

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