Thetford Roofers carries out lead flashing installation and repair for homeowners in Mildenhall, keeping chimneys, skylights, valleys and abutments properly sealed against rain and frost.
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Lead flashing is the strip of formed metal that seals the joint between a roof surface and a vertical element - your chimney stack, a parapet wall, a dormer, a skylight frame or a valley where two roof slopes meet. Without a sound lead seal at those junctions, rainwater tracks down behind the tiles and into the roof structure. It is one of the most common sources of internal damp that is wrongly blamed on broken tiles.
Lead has been used on British roofs for centuries because it is soft enough to be dressed into tight shapes, durable enough to last several decades when installed correctly, and resistant to the repeated thermal movement that cracks harder sealants. A well-fitted lead flashing will flex with the building through summer heat and winter frost without opening up.
Most domestic lead work falls into one of these categories:
Each of these requires the lead to be cut, shaped and dressed on site. Prefabricated push-fit flashings exist but they are not a like-for-like replacement for proper formed lead on a traditional roof.
A straightforward chimney flashing repair in the Mildenhall area typically runs from around £150 to £400 depending on access and the amount of lead involved. Replacing all four sides of a medium chimney stack with new lead - step flashing, back gutter, front apron and soakers - generally costs between £400 and £900. Valley relining varies with length but expect £300 to £700 for a typical domestic valley. These are honest working-range figures; the actual price depends on what we find when we look at the job.
This is the section most roofers skip, and it is the one that saves you the most money over time. Lead work that is installed correctly still needs occasional attention. Knowing what to do - and when - means you catch small issues before they become water damage inside your home.
Moss, lichen and debris collect against the base of chimney stacks and along the edges of parapet flashings. When that debris holds moisture against the lead, it accelerates oxidation at the edge and can work under the flashing over time. Clear debris away from around chimney bases and valley mouths each autumn, using a soft brush rather than a pressure washer. Pressure washing drives water under flashing edges and loosens mortar pointing.
On chimney stacks, the top edge of the step flashing is tucked into a raked mortar joint called a chase, then sealed with fresh mortar or a lead wedge. This mortar pointing is the part that fails first - frost gets into hairline cracks, expands, and opens the joint. Walk around your property after a hard frost and look up at chimney stacks. A crack in the pointing does not always mean the lead itself has failed; re-pointing the chase is a much cheaper job than replacing the flashing.
If you can safely see the chimney from a bedroom window or a flat section of roof, look for mortar that has turned white or crumbly, or gaps where the mortar has dropped out. That is your early warning. Catching it at that stage means a roofer can re-point the chase and re-dress the lead - typically a half-day job. Leave it another winter and the flashing may lift or crack, which is a bigger repair.
You do not need to get on the roof to spot early trouble. Inside the property, look for:
Outside, look for lead that has slipped downward, visible gaps between the lead and the brick, or lead that looks crinkled or split rather than smooth. A slipped flashing can sometimes be re-dressed and re-pointed without full replacement if caught early enough.
It is common to see old repairs where someone has run a bead of mastic sealant over a leaking flashing. Mastic moves differently to lead under thermal cycling, so it cracks away from the edge within a year or two and the leak returns. Expanding foam is worse - it traps moisture and is very difficult to remove cleanly when a proper repair is eventually done. Neither product is a substitute for correctly fitted and pointed lead. If a previous owner has used these, tell the roofer; it affects how the repair is approached.
When gutters are cleaned or repaired, debris is often disturbed around parapet walls and abutment flashings. It is a sensible habit to cast an eye over any lead near the gutter work after it is done. Flashing edges can be dislodged by ladders or by the pressure of debris being cleared.
A lead work inspection is not just a look from the ground. A roofer should check that all chase joints are sound and properly pointed, that the lead is dressed tightly against the masonry without gaps, that no section has slipped or cracked, and that soakers (where present) are still correctly positioned under the tiles. On an older property, it is also worth checking whether lead code 3 was used where code 4 or 5 would be more appropriate - thinner lead is more prone to cracking with age.
From our base in Thetford we cover Mildenhall and the surrounding area including Mundford, Brandon, Feltwell, Methwold, Watton, Barnham, Elveden, Croxton and the villages between. If you are unsure whether we cover your location, call us and we will tell you straight.
If you have noticed a damp patch near a chimney or valley, or if your lead flashings have not been looked at for several years, call Thetford Roofers and we will arrange a roof survey. We will tell you exactly what needs doing and give you a price before any work starts.
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Call any time. Calls are answered day and night and passed straight to our roofers.
