Inspired by a Roofing & Guttering Matters guide. This article draws on the practical video “Installing or Repairing Lead Front Apron Roof Flashing” from Roofing & Guttering Matters Ltd, based in Halesowen in the West Midlands. Their videos are solid trade-level instruction and they cover the chase-fixing detail well - the part that catches a lot of amateur repairs out.
1. Assess the flashing from the ground first
Before going anywhere near a ladder, look at the flashing from the ground with a pair of binoculars if you have them. You are checking whether the lead has pulled away from the wall, whether the mortar pointing in the chase (the groove cut into the brickwork) has failed, or whether there are visible cracks in the lead itself.
A damp patch on the internal wall or ceiling below is usually a good clue. That said, water can travel a fair distance from the actual entry point, so do not assume the damage is directly above the wet patch.
2. Set up safe access
You need to get onto the roof. Use a proper roof ladder that hooks over the ridge - not just a standard ladder propped against the tiles. On pitched roofs, walking directly on the tiles can crack them; a roof ladder spreads your weight. Take someone with you if possible to hold the ladder at the bottom and pass tools up.
If the roof is steep, the flashing is high up, or you are not confident with heights, this is the point to call a professional. A wet ceiling is expensive to repair; a fall is much worse.
3. Clean back the old pointing
The top edge of the lead flashing tucks into a chase cut into the mortar joint between bricks or into the brickwork itself. Over time the pointing cracks or crumbles, and the lead drops down or lifts in the wind. Use a cold chisel and club hammer to rake out the old mortar from the chase - go back at least 25 mm to get to sound material.
Brush out the dust and debris with a stiff brush. If the chase looks loose or crumbly further back, keep going until you hit solid mortar.
4. Re-dress the lead back into position
If the lead has only lifted or pulled away slightly, it can often be dressed back into the chase without replacing it. Use a bossing mallet or the handle of a hammer to gently work the top edge of the lead back up into the groove. Lead is soft and malleable - it will move with moderate force.
Do not fold or crease the lead sharply - creases can crack over time as the metal expands and contracts with temperature changes. Aim for smooth, gradual bends. If the lead has cracked through, it needs replacing rather than dressing back.
5. Re-point the chase
Mix up a stiff mortar (3:1 sharp sand to cement works well, or use a proprietary flashing mortar). Push the mortar firmly into the chase with a pointing trowel, packing it in behind the top edge of the lead. Aim to fill the full depth of the chase.
Finish the pointing neatly - a weathered joint (slightly angled to shed water) is the traditional profile for exposed work like this. Leave it to cure for at least 24 hours before wetting it or applying sealant.
6. Seal any cracks in the lead
Small cracks or pinholes in the lead face can be repaired with lead repair tape (a self-adhesive lead-backed tape, sold by roofing merchants) or a good-quality lead-compatible sealant such as CT1 or Stixall. Work the product firmly into the crack and smooth it flat. Do not use standard silicone - it does not bond reliably to lead and will peel off within a couple of seasons.
For larger cracks or holes, lead repair tape cut to size and dressed carefully into the profile gives a more durable result than sealant alone.
7. Apply patination oil
New lead and freshly dressed lead is bright silver-grey and will run a temporary white stain (lead carbonate) down the tiles until it weathers. Apply a thin coat of patination oil over any bare or fresh lead to speed up the weathering and stop the staining. It turns the lead a darker grey within a few days.
Patination oil is cheap, widely available at roofing merchants, and takes about five minutes to apply with a cloth. Worth doing - white staining on the tiles and gutters looks terrible.
When to call a handyman
If the lead has cracked through, lifted badly in multiple places, or is very old and brittle, it is usually better to replace it entirely rather than patch. Richard can assess the flashing, carry out repairs, or re-lead where needed. Call sooner rather than later - small leaks into a roof space do not stay small for long.
Lead flashing repairs in East Kent
The Sandwich Handyman handles roof flashing repairs, re-pointing, and property maintenance across Sandwich, Deal, and the surrounding villages.
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