The short answer
A sound lead roof on a home is not normally a hazard to the people living under it. The sensible precautions come when lead is cut, dressed or removed, because dust and fumes can be breathed in or carried on hands, and when rainwater from lead is collected or used. Keep children away from work, wash hands before eating, and ask for advice if you are unsure.
What risk lead actually presents on a roof
Lead becomes a concern when it gets into the body. The Health and Safety Executive describes the routes as breathing in lead dust, fume or vapour, and swallowing lead, for example by eating, drinking or smoking without washing hands and face. A sheet of lead sitting weathered on a roof, behind a chimney or in a valley, is not doing either. Its surface has a pale grey film, and that film stays where it is unless the metal is disturbed.
This page gives general precautions and is not medical or legal advice. If you or a member of your household is pregnant, or you have young children and are worried about exposure, speak to your GP or health visitor.
The distinction to hold on to is between lead left alone and lead being worked. A flashing that has been in place for fifty years and is undisturbed is a different matter from one being cut, scraped or burned off.
Handling, cutting and dust during a job
The precautions during roofwork are ordinary good practice. Lead should be cut with the right knife and shears rather than a grinder, because a power tool creates dust. It should be dressed with a lead dresser and a mallet. Fine dust needs washing up rather than dry sweeping, and offcuts go into a container so they do not lie about the site.
Hot work
Heat is where lead becomes a different sort of problem. Welding or burning lead off a surface produces fume, and HSE lists hot cutting and the burning of old lead paint among the processes that create lead dust, fume or vapour, so naked-flame work on old leadwork needs thought. Our page on pointing lead flashing deals with the cold work at the top edge of the lead, not the hot work.
Hands, food and clothing
Lead dust reaches the mouth from hands. People who work with it wash before eating, drinking or smoking, and keep work clothes apart from the house. That applies to anyone, including a homeowner doing a small job. If you are weighing up a DIY repair, our guide to what is involved in lead soakers shows how fiddly the hidden parts are.
Work around loft spaces needs the same sense. Dust settles on stored items and insulation, and it should not be swept into a general cloud.
Rainwater, run-off and the garden
Rain running over lead can pick up traces of the metal, and that is the reason people ask about water butts. Rainwater collected from any roof is not drinking water, whatever the covering, so do not drink it or cook with it. If you want to use collected water on vegetables you will eat and the roof carries a lot of lead, ask your council's environmental health team for advice first. A water butt for the garden is better served by a roof that has no lead feeding the gutter.
That is general guidance and not a measured result for any particular roof. If you are collecting rainwater, think about where the downpipe starts. A short run of lead flashing at a chimney is a small contribution next to a whole lead roof, though the same reasoning applies.
The white marks you sometimes see below lead are a different matter. They are a surface deposit of lead carbonate that washes down in the rain, and they stain brick or stone below. Our answer on white staining below lead explains why they appear and how to deal with them. Do not scrub the stains dry, as that lifts dust.
Old lead, new lead and what to do before work starts
Old lead paint and old lead pipes belong to a different conversation, so keep them apart in your mind from roof sheet. Sheet lead on a roof is a metal, not a painted coating.
Before work on an older house, think about what sits around the lead. Dust in a loft can include years of everything else. Putting down sheeting and keeping the family out of the working area for the day is the least that is needed. A reputable roofer will tell you how they plan to contain waste and clear the site.
Where the building is a church, school or village hall, it is open to the public and the arrangements are tighter. The people responsible for the building will often have their own requirements on dust and access, and the usual approach is to agree a plan for it first.
Disposal needs care too. Old lead has scrap value and is recycled, so it should not be mixed into a general skip. We remove it from your site when we clear up.
What to ask a roofer about lead, and how we work
Put four questions to any roofer: how will the lead be cut, how will dust be contained, where do offcuts and old sheet go, and is any hot work planned? Vague replies deserve a second question.
We cut with knives and shears, keep offcuts in a container, wash down rather than sweep dry and take waste away when the job is done. If the survey finds old leadwork that would have to be burned or ground off, you hear about it before the quote is written.
The code of sheet does not affect safety, but it does affect how long the work will last. See our answer on the lead code for flashing for the choice. Our written 10-year workmanship guarantee applies to the work we do. For the whole service, see lead roofing in Stroud. Ring 01453 933613, or send the form with a photo of the lead, and we will talk it through.