A roof valley is the internal angle formed where two sloping sections of roof meet, channelling rainwater down towards the guttering. Because valleys carry a concentrated flow of water, especially during heavy rain, they are one of the most common places for leaks to develop on a pitched roof. If you have noticed a leak that seems to appear in a particular spot every time it rains, a valley is often the first place worth checking.
Many properties in Neath, particularly those with extensions or more complex roof shapes, have one or more valleys, so understanding why they fail and how they are fixed is useful for any homeowner dealing with a persistent leak that seems to come and go with the weather.
Why valleys fail
Valleys are usually lined with lead, GRP or a valley tile system, and each of these can fail in different ways over time. Lead linings can crack, split or work loose from movement in the roof structure, while cheaper valley trims can become brittle and crack with age and exposure. A common cause of leaks is simply debris. Moss, leaves and general roof debris tend to collect in valleys because of the way water funnels through them, and a blockage can cause water to back up under the surrounding tiles or slates rather than running away freely. Poor original installation, where the valley was not formed with enough of an overlap or fall, can also be a contributing factor, as can general wear where tiles either side of the valley have slipped and are no longer sitting correctly against the lining.
The extent of the repair needed depends on what is actually wrong. Sometimes a leak is resolved simply by clearing a blockage and resealing a joint. In other cases the valley lining itself has failed and needs to be replaced, which involves carefully lifting the surrounding tiles or slates, fitting a new lining and resetting the roof covering around it so that water sheds correctly again.
It is worth noting that water does not always show up directly below where it enters the roof. It can run some distance along a rafter or the underside of the roof felt before dripping onto the ceiling, which is why a leak that seems to be in one room can sometimes be traced back to a valley elsewhere on the roof entirely.
Getting a valley repaired properly
Valley repairs are not always straightforward to diagnose from the ground, so it pays to have someone experienced take a proper look before any work begins. T & T Roofing and Home Improvements Ltd carries out leadwork and flashing repairs, including valley work, for homeowners across Neath, and offers a free, no-obligation inspection to identify exactly where a leak is coming from before recommending a fix. Call 07766 547309 to arrange a visit.
Get a Free Roofing Quote in Neath
Every roof is different — the fastest way to get an accurate answer is a quick chat with our team.