Lead Work in Stanton

Expert Lead Work
in Stanton

When lead work starts to fail, it rarely announces itself quietly

A small damp patch on a bedroom ceiling, a tide mark on a chimney breast wall, or mortar that keeps crumbling away from a flashing chase - these are the signs most homeowners notice first. By the time water has reached the inside of a property, the lead itself may have been failing for months. Understanding what to look for, and why failures happen, helps you act before the damage becomes expensive.

What lead work actually does on your roof

Lead is used wherever two surfaces meet on a roof - at chimneys, where a roof meets a wall (the abutment), in valleys between two slopes, around dormer windows and skylights, and on flat roof edges. Its job is to bridge the gap between materials that expand and contract at different rates. A properly formed lead flashing flexes with the building rather than cracking under the movement.

Lead soakers sit beneath the tiles at the sides of a chimney or dormer. They slide under each course of tile and overlap the next soaker below, forming a stepped waterproof layer that you cannot see once the step flashing is dressed over the top. If soakers are missing or were never fitted in the first place, water tracks down behind the flashing and into the roof space without any obvious external sign.

The warning signs to look for

Most lead failures show themselves in one of a handful of ways. If you know what to look for, you can describe the problem accurately when you call a roofer - and avoid paying for a full replacement when a repair will do.

• Cracking or splitting in the lead itself. Lead that has been worked in one piece that is too long will pull apart at stress points as it heats and cools with the seasons. Cracks are usually visible as fine lines running across the width of the flashing.
• Lead that has slipped or pulled free from the chase. The top edge of a flashing is tucked into a mortar chase cut into the brickwork. If the mortar was raked out too shallowly, or the lead was not wedged properly, it works loose over time and drops away from the wall. You can sometimes see a gap from the ground by eye.
• Moss and debris trapped at the base of a chimney or dormer. Organic material holds moisture against the lead and accelerates corrosion. It also blocks the natural drainage path, pushing water back under the flashing.
• Damp patches that appear after rain but dry out between showers. This pattern points to an active water entry rather than condensation. If the damp patch is directly below a chimney, a valley or a parapet wall, lead is the most likely cause.
• Staining on external brickwork below a chimney. White efflorescence or dark tide marks on the face of a stack below flashing level suggest water is tracking behind the lead rather than over it.
• Lead that has been patched with sealant or flashing tape. Mastic-based sealants and self-adhesive tape are not a permanent fix for lead. They tend to last a few years at most before they harden, crack and admit water again. If you can see grey or black sealant along a flashing line, treat it as a sign that the underlying lead needs attention.

What causes lead work to fail

The most common cause is incorrect bay lengths. Lead must be installed in sections no longer than about 1.5 metres, sometimes less on steep pitches or fully exposed locations. When a roofer lays lead in a single long piece to save time, it cannot accommodate thermal movement and splits. This is entirely a workmanship issue - well-graded lead installed to the correct bay length and dressed properly will outlast most other roof materials.

Age is the other main factor. Lead can last 50 to 100 years on a well-maintained roof, but the original installation quality varies enormously. On older properties where the lead has never been touched, the flashing may simply have reached the end of its service life. A full replacement is the right answer in that situation - patch repairs over very old lead rarely hold for long.

Frost is particularly hard on lead that has already been weakened. Water that has seeped into a crack or under a lifted edge expands when it freezes, widening the gap. After a cold winter, it is worth having flashings checked if they are more than a few decades old.

Poor pointing is also a factor. The mortar that fixes the top of a flashing into its chase needs to be raked back to a proper depth (at least 25mm) and packed with lead wedges before it is pointed up. Shallow or unkeyed mortar fails within a few years, and the flashing drops away from the wall.

Repair or full replacement - how to decide

If the lead is structurally sound but the mortar fixing has failed, re-raking the chase and re-pointing with fresh mortar is often enough. If the lead itself is cracked, split, perished or has been repeatedly patched, replacement is the better value. Continuing to repair old, over-worked lead costs more in the long run than a single proper job.

For valleys, the condition of the tiles or slates either side of the lead also matters. A valley re-lead is a good moment to replace any cracked tiles adjacent to it - lifting them is part of the job anyway.

What a proper lead work job looks like

Good lead work uses the correct code of lead for the application (Code 3 or 4 for soakers, Code 4 or 5 for flashings and valleys, Code 5 or 6 for flat roofs). The lead is cut to the right bay lengths, dressed into shape with a bossing mallet or lead dresser rather than cut and folded with scissors, and fixed with lead clips rather than nails through the face. The chase is raked to depth, the lead is wedged with lead plugs at regular intervals, and the pointing is finished neatly with a mortar mix that will stay flexible.

Once the work is done, the tiles or slates disturbed during access should be relaid and the area around the base of the chimney or dormer should be left clear of debris. A good roofer will also check the adjacent tiles for cracks or slipped pegs while they are up on the roof.

Lead work in Stanton and nearby

We cover Stanton and the wider area including Diss, Scole, Roydon, Norton, Hopton and surrounding villages. If you have noticed any of the warning signs described above, call us to arrange a roof survey so we can assess the lead and give you a straightforward account of what needs doing and why.