“Light-weight fixtures, enthusiasts, vents and skylights are nearly always at the bottom place. If a residence has a leak inside the roof or if elevated appliances for example HVAC units start to leak, gravity does the remainder of the do the job and provides the water pooling into these places.” https://roofreplacement06049.bloguetechno.com/the-definitive-guide-to-roofing-supplies-68930371