Damp patches appearing on ceilings or around chimney breasts are a common concern for homeowners in Caerphilly, and lead flashing is very often the source of the problem. It is easy to overlook because flashing sits at the joins and edges of a roof, out of sight and rarely thought about until something goes wrong.
Yes, damaged lead flashing can absolutely cause damp inside a home. Flashing is what seals the vulnerable junctions on a roof, such as where a chimney meets the roof slope, where a roof meets a wall, or around dormer windows and roof valleys. When it fails, water has a direct route into the property that ordinary tiles or slates were never designed to cover on their own.
How flashing fails and lets water in
Lead flashing can crack, lift, or come away from its fixing points over time, particularly where it has been exposed to years of weather and thermal movement as the lead expands and contracts with temperature changes. Mortar pointing that holds the top edge of the flashing into a chimney or wall can also crumble and fall away, leaving a gap for water to track behind the lead and into the property. Poor original installation, physical damage from storms or fallen debris, and simple age can all contribute to flashing failure.
In some cases flashing is not lead at all, or has been repaired in the past with an unsuitable material or an ill-fitting patch, and this kind of makeshift fix tends to fail again fairly quickly. On older Caerphilly properties in particular, flashing that has never been properly renewed since the roof was first covered can be a weak point that eventually gives way even if the tiles or slates around it are still in reasonable condition.
Because flashing sits at joins rather than open roof slopes, water that gets past it can travel some distance before it shows up as a damp patch, which means the visible damage inside a Caerphilly home is not always directly beneath the point where the flashing has actually failed. This is one of the reasons damp problems linked to flashing can be misdiagnosed if the whole roof is not properly inspected.
What to do about it
If you have noticed damp patches, staining, or a musty smell in rooms near a chimney or roof junction, it is worth having the flashing checked rather than just treating the symptoms inside. Repairing or replacing damaged flashing properly, along with any deteriorated pointing around it, addresses the actual cause rather than papering over the effects.
T & T Roofing carries out leadwork and flashing repairs across Caerphilly and can identify whether flashing is behind a damp problem in your home. Contact us for a free, no-obligation quotation and inspection.
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