The short answer
You can, in the sense that nothing stops a homeowner buying lead and a bossing stick. In practice it is a job we advise against. The work is at roof height, the lead has to be shaped to the tile or slate, and mistakes such as the wrong code or a shallow chase leak later, usually after the first wet winter.
Lead flashing looks simple from the ground. The difficulty is in the dressing, the fixing and the height you have to do it at.
The height problem
Lead flashing sits where a roof meets something else: a chimney, a wall, a dormer or a roof window. Those places are rarely at the eaves. A chimney stack often stands near the ridge, where the two slopes meet at the top, and a party wall flashing runs along the edge of a slope above a drop.
Is it safe to do from a ladder?
Not really. Lead is heavy, awkward in wind, and needs both hands to dress. A ladder gives a poor working position and nowhere to put tools. Roofers work from scaffold, a tower or a crawling board resting on the slope, and they tie everything off out of habit.
Falls from roofs and ladders injure people every year, and a job that saves a few hundred pounds is not worth that risk. To inspect your flashing, use binoculars from the ground or look from a window. Photograph anything lifted, cracked or stained, and send it to us. After a roof survey you see pictures of your own flashing and receive one written price.
Where scaffold is needed on a road or pavement, a licence from the highway authority applies, and the scaffolder and we handle the paperwork together. Most owners find that setting up safe access is a bigger task than the lead itself.
Dressing is a skill, not a step
Dressing means shaping the lead by hand so it follows the surface beneath. With a flat slate it is fairly forgiving. With a profiled tile, a stone coping or an uneven brick course, it is not. Lead that is hammered too hard thins and cracks. Lead left loose lifts in wind.
What goes wrong most often?
Four mistakes appear again and again. The lead is too thin for its position. The pieces are cut too long, so thermal movement tears them, as our answer on lead size limits explains. The top edge is not chased deep enough into the wall. And the laps are too short, so wind-driven rain passes under.
Sealant is the usual attempt to cover these faults, and it nearly always makes the later repair harder. Lead is meant to be held mechanically, not stuck. Our answer on sealant on lead flashing covers why.
A professional has dressed lead over hundreds of different surfaces. That experience shows in the first heavy rain after the job, not on the day it is finished. Handing a split flashing to a roofer early costs less than clearing up the plaster damage that follows a poor fix.
Codes, laps and the right fixings
Lead sheet is sold by code. The Royston Lead brochure lists code 4 at 1.80 mm and code 5 at 2.24 mm, with code 3 at 1.32 mm for soakers only, the small folded pieces that sit under slates or tiles. Buying code 3 for a long flashing is a classic DIY mistake, because it looks the same on the roll.
Does it matter which fixings you use?
Yes. Clips, wedges and nails must suit lead, and the wrong metal causes corrosion where the two touch. Wedges are lead or purpose-made, and the chase is filled with the right mortar or sealant, not whatever is left in the garage.
Where a flashing meets a chimney stack, a separate set of pieces is needed: the apron, step flashings and a back gutter. Our answers on the chimney apron flashing and the chimney back gutter show how many separate pieces make up one stack.
Getting any one of them wrong lets water behind the rest, so each piece depends on the others being right. A single missed lap near the corner can undo a full day of careful work, and it will not show until rain arrives from the right direction.
When a small repair is reasonable
Some jobs are within reach for a confident owner on a low roof, such as clearing moss from a ground-level lean-to, or re-seating a loose flashing on a single-storey extension from a safe, stable position. Even then, the repair is best made once the cause is understood.
How do you know whether it is a quick fix?
Ask what has actually failed. A lifted edge may be a symptom of a split further along, or of rot under the lead. Our guide to the signs of failed flashing lists what to check from the ground.
If the answer is not clear, a survey is cheaper than a second repair. Keep any paperwork for work done, because a buyer, surveyor or insurer may ask to see it later. Our lead work page covers the range of flashings we handle. Send a photo of the area and we will tell you plainly whether the job needs a roofer or can wait for the weather to improve.
A repair made in a hurry, with the wrong material, is the main reason we are called to fix flashings twice.
More on DIY lead work
What tools do you need to fit lead flashing?
A bossing stick or dresser, a lead knife, a hammer, wedges, a chasing tool for the wall, and a safe way to reach the roof. The tools are cheap. The skill to use them without thinning or splitting the lead is what takes years to build.
Is fitting lead flashing harder than replacing a gutter?
They are different jobs. A gutter is at the eaves and can be done from a tower. Lead flashing sits higher, is shaped to fit and fails quietly behind the covering. Errors appear as a stain on the ceiling long after the day you finished.
The full picture: Lead work in Taunton ยท More short answers