Not necessarily, although flat roofs do have to work harder to keep water out than pitched roofs. Water drains away more slowly, so the roof covering, seams, edges and drainage all need to remain watertight. This is one reason drainage and periodic inspections are particularly important for flat roofs.

However, a professionally installed flat roof shouldn’t routinely leak. Modern felt and EPDM systems are designed specifically for prolonged exposure to the weather and can provide reliable protection for decades when correctly installed and maintained.