German roof insulation experts warn of rising heat‑wave risks

Heat waves are arriving earlier and becoming more intense across Germany, turning attic spaces into saunas. Experts Jan Juraschek of the Schleswig‑Holstein roof‑layer association and Stephan Ziemann of the Berlin roof‑layer association say typical roof insulation of only 14‑18 cm cannot prevent roof‑surface temperatures above 70 °C, creating a 45 °C gap to the comfortable indoor range of 23‑25 °C.

They stress that any thermal bridge—poorly installed insulation, gaps around roof windows, or inadequate shading—reduces performance, leading to higher winter heating costs and summer overheating. Recommended measures include proper up‑roof insulation, modern low‑bridge roof windows, external shading devices, automated ventilation, and using photovoltaic panels to power cooling equipment. Roofing firms can provide comprehensive retrofit solutions.