Why can't interior wall paint and exterior wall paint be mixed together?

1. Different physical properties:
There are significant differences in composition and characteristics between interior wall paint and exterior wall paint, including differences in drying time, adhesion, durability, and other aspects. If mixed, it may lead to poor adhesion of the coating, cracking of the paint film, and other problems, affecting the coating effect and service life.
2. Different environmental adaptability:
Interior wall paint is mainly designed for indoor environments, and its performance advantages lie in its aesthetic and environmental performance in indoor environments. And exterior wall paint needs to have stronger weather resistance to cope with various challenges brought by outdoor environments. Mixing interior and exterior paint can damage their original design and functional characteristics, affecting the painting effect and service life.
Therefore, in order to ensure the construction effect and coating quality, it is necessary to clearly distinguish between interior wall paint and exterior wall paint when selecting coatings, and avoid mixing them. Only by selecting appropriate coatings according to specific needs can ideal decoration effects be achieved and the service life of buildings be extended.