The Five Most Common Reasons Roofs Leak
A leaking roof might not always be noticed immediately, as, depending on the specific problem and its severity, it can start as a gradual build-up of damp. If left to worsen, however, the leak can become costly not only in terms of repairs, but also in potential damage to possessions or to other parts of your home's structure. There are a number of issues that can result in roof leaks, but here are the five most common.
1: Problems with SlatesOften due to adverse weather conditions, slates can slip, become broken, or detach from the roof completely. If the slates have slipped or come completely away, there's a good chance you can spot the problem from the ground. In the latter case, you might find slates on the ground. If they are simply damaged, however, there's a strong possibility that you won't be able to tell without inspecting them closely. Roofs have an underlay below the slates, but if unusually high amounts of rainwater can get past gaps in the slates, the underlay might not be able to cope with the increased pressure, causing a leak.
2: Underlay DamageEven if the tiles are all present and intact, felt underlay can be damaged by bad weather. For example, strong winds can blow rain underneath the tiles, where it reaches the underlay. Usually, it is then carried to the guttering, but repeated exposure can eventually lead to the underlay tearing or even beginning to rot. You should be able to see from the loft if this is the problem, as the underlay will be visible.
3: Valley Gutter IssuesIf valley gutters are not properly installed, or they have become blocked, water can collect in certain spots. This will cause leaks at the point where it pools. Sometimes the valleys are not properly sealed, or the seals have become damaged through age or extremes of temperature. This will lead to leaks along the valley's length as water runs along.
4: Flashing and Joint ProblemsFlashing are the pieces of thin metal that keep water out around roof joints, chimneys, skylights and vents. This metal can corrode and crack over time, letting in moisture. It can also sometimes partially come away. Either of these problems mean it will need repairing or completely replacing. Mortar joints and beds in chimneys can also suffer frost damage. A roof inspection can reveal if a roof suffers any of these types of issues.
5: Blocked GutteringGutters are designed to carry excess water away from your roof. If they are blocked, however, water will build up and overflow back onto the roof, where it can leak through into the house. This should be quite easy to spot, as water will be clearly overflowing at the point of the blockage. Gutter problems are more common in autumn and winter, when leaves and moss can fall into the guttering and cause blockages. This is simple to fix by removing the debris, but if left for too long can lead to underlay damage. Regularly cleaning gutters will help to prevent them becoming clogged.