While solar panels can be installed on most types of roofs, there are some roof types that may be less suitable or require extra attention. Here are some examples:

1. Thatched roofs: Installing solar panels on thatched roofs can be complicated due to the flammability of the thatch. It requires specific safety measures and may pose potential fire risks.

2. Asbestos roofs: Roofs containing asbestos require special procedures and permits for removal. If your roof contains asbestos, it must be removed before solar panels can be installed.

3. Slate roofing: Slate is a heavy material, and the installation of solar panels may require additional structural reinforcement to support the weight of the solar panel system.

4. Shady roofs: Roofs that are constantly in the shade, such as those of tall buildings or surrounded by tall trees, may be less suitable because shade can reduce the efficiency of solar panels.

5. Very steep roofs: Very steep roofs can make installation difficult and access for maintenance challenging. It can also increase the risk of accidents during installation and maintenance.

6. Roofs with insufficient load-bearing capacity: Not all roofs have sufficient load-bearing capacity to support the additional weight of solar panels and the mounting system. In some cases, structural reinforcement may be needed.

It is important to emphasize that these points do not necessarily mean that solar panels are completely impossible on these roofs. In some cases, modifications and reinforcements can be made to improve suitability. A qualified solar installer can perform a roof assessment and recommend the best solutions for your specific situation.