So the roof pitch is beneath the windows design limits then?We have 5 Velux's fitted to a single storey extension that was built back in 2014, so 9 years old now. After a lot of rain this week, persistent, but not particularly heavy, we have noticed 3 of the Velux windows have developed a leak exactly where others have also had an issue. I know the roof pitch is very low so maybe this is contributing to the issue, but it would appear to be a common issue with Velux windows as they age.