Ely Roofers carries out lead flashing repairs and installation for homeowners in Chatteris, handling every stage of the job from first inspection to finished clean-up.
A lot of homeowners hand their roof over to a tradesperson without knowing what a proper lead work job involves from start to finish. Understanding the sequence helps you judge whether the work being proposed makes sense, whether the price reflects what is actually needed, and whether the finished result has been done properly. Here is how a competent lead job is carried out.
Before any lead is ordered or scaffold erected, the roof needs to be looked at properly. A genuine inspection means getting up to the lead, not just looking from a ladder or pointing at it from the garden. A roofer assessing a chimney flashing needs to check every component: the front apron, the step flashings on each side, the soakers beneath them, and the back gutter. Each one can fail independently of the others.
At a valley, the inspection should include lifting a tile or two at the edge of the valley to see the condition of the sheet underneath, rather than just looking at what is visible. A closed valley - where tiles are cut and laid over the lead - cannot be assessed at all from the surface; the tiles have to come off.
The inspection should also check for secondary damage. A failing flashing that has been leaking for some time may have left the roof deck, battens or rafters below it damp or softened. Carrying out a neat lead repair on top of wet or rotting timber is a waste of everyone's time and money.
Safe access is essential before any work starts. For most chimney and valley work on a pitched domestic roof, this means either a scaffold tower or a section of scaffolding depending on the height and pitch. For lower sections of roof, a suitable ladder with a roof hook or a crawl board may be all that is needed.
Once access is in place, the preparation begins. Old lead and the mortar holding it is carefully removed without damaging the tiles, slates or brickwork around it. At a chimney, this means raking out the mortar joint into which the flashing was bedded, removing the old lead and any corroded clips, and checking the brickwork behind. Crumbling or spalled brickwork at the flashing line needs to be made good before new lead goes in; otherwise the new material will work loose at the first frost.
If soakers are being replaced, the relevant tile courses have to be lifted and set aside. Soakers are individual lead pieces that sit between each tile and the roof batten, with an upstand against the abutment wall. Taking tiles off and relaying them adds time but cannot be skipped on a proper step flashing job.
Lead sheet is cut on site from roll stock to the sizes the job requires. For most domestic flashings, code 4 (1.80 mm) is used; code 5 (2.24 mm) is specified for back gutters and wide valley linings where more durability is needed in a demanding position.
Dressing lead means shaping it to the profile of the surface it needs to seal - bending it around corners, pressing it into mortar joints, and forming the correct upstands and overlaps. This is done with a bossing mallet and dresser rather than by forcing the lead with a hammer, which would thin the sheet and cause early cracking. Lead must be worked gently; overworking it in one spot creates a stress point that will split.
Each flashing is installed in bays, with individual lengths lapping over each other rather than running in one continuous sheet. The maximum recommended bay length is around 1.5 metres. This allows the lead to expand and contract with temperature without buckling or cracking. Skipping expansion bays is a common shortcut that leads to premature failure.
Lead tacks or clips - strips of lead fixed into the masonry - hold each bay in position so it cannot be lifted by wind without restricting its movement. The number and position of clips matters; a flashing with clips only at the ends will still flap in the middle over time.
Once the lead is dressed and clipped in position, the top edge that sits inside the mortar joint is pointed in. This is done with a suitable mortar - typically a sand and cement mix, though in some situations a specialist lead mortar or silicone-free sealant is more appropriate. The pointing should be a neat, slightly recessed bead that sheds water rather than a thick mortar fillet plastered across the face of the lead. Overly thick pointing cracks as the lead moves, which lets water back in.
Any tiles that were lifted during the soaker replacement are relaid in the correct course with the nibs hooked onto the battens. Ridge tiles at the top of a valley or chimney that were disturbed are rebedded and pointed. Nothing is left loose.
Once the work is complete, the area should be checked from below as well as at roof level. Any mortar droppings on tiles or in gutters should be cleared - hardened mortar sitting in a gutter can block it just as effectively as leaves. Tile fragments, old lead offcuts and packaging are removed from the roof and from around the property.
It is reasonable to ask the roofer to show you the finished work before they leave, either in person if access allows or via photographs taken at roof level. A competent tradesperson will not object to this. You should be able to see that the lead is neatly dressed with no visible gaps, that the pointing is tidy and recessed, and that no tiles have been cracked or displaced during the work.
New lead has a bright, silvery appearance when first installed. Over the following months it weathers to the familiar dark grey patina. During the initial weathering period, runoff from new lead contains a small amount of lead carbonate. This is worth knowing if you collect rainwater from the affected roof section, though for normal garden use it is not a significant concern.
Some movement of a new flashing during the first winter is normal - the lead is settling into its working position. What is not normal is a flashing that visibly lifts, gaps that open at the pointing, or mortar that falls away within weeks. If any of these happen, contact the roofer promptly.
We carry out lead flashing repairs and installations for homeowners in Chatteris and the surrounding area, including work in nearby Ely. A good lead job follows the sequence above: proper inspection, correct materials, careful dressing and a tidy finish. Call us to arrange a roof survey if you have a leak or suspect your lead needs attention.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
