What is another factor that can prevent good adhesion of bitumen?

Good adhesion of bitumen is crucial for the performance and longevity of built-up roofing systems. One significant factor that can hinder this adhesion is excessive moisture. When the surface to which bitumen is being applied is damp or wet, it can create a barrier that prevents the bitumen from properly bonding. This moisture can lead to the formation of blisters, delamination, or other issues, ultimately compromising the roofing system's integrity.

While dirt and debris can also impact adhesion, excessive moisture is generally a more critical concern because it directly interferes with the chemical and physical bonding process. Making sure the application surface is dry is fundamental for ensuring that the bitumen can adhere effectively, creating the required watertight seal.