Lead roofing: lifespan, defects, risks and maintenance

Why is lead used as a roof covering?

Lead is used because it is durable, easy to shape and resists corrosion. It has been a popular choice for roof coverings for centuries, particularly in the UK, and is often found on historic buildings, churches and high-end properties.

• Malleability: lead can be easily shaped and moulded to fit complex roof designs and details, which suits historic buildings with intricate architectural features.
• Durability: it withstands harsh weather, including intense sun, heavy rain, snow and high winds.
• Corrosion resistance: unlike many metals, lead does not corrode easily.
• Appearance: over time lead develops a natural patina, which adds to its appearance and gives an additional layer of protection against the elements.

Buying a home with an older roof? Get a survey price for the home you are buying.

How long does a lead roof last?

When installed correctly and maintained properly, a lead roof can last over 100 years. Many historic buildings still have their original lead roofs. This longevity comes from lead's resistance to corrosion and its ability to withstand extreme weather.

What affects the life of a lead roof?

• Installation quality: poor workmanship can lead to premature failure.
• Environment: lead roofs in coastal areas may degrade faster due to salt exposure.
• Maintenance: regular inspections and maintenance can significantly extend the life of the roof.
• Thickness: thicker lead sheets tend to last longer because they resist wear and tear better.

What defects are found in lead roofs?

The typical defects are fatigue cracking, sagging and corrosion, which can lead to leaks and structural damage if not dealt with promptly.

• Fatigue cracking: cracks that develop over time from the natural expansion and contraction of the lead.
• Sagging: lead that is not properly supported can sag, especially in warmer temperatures.
• Corrosion spots: lead is resistant to corrosion but not immune. Acidic rain, pollutants and areas where leaves gather and decompose can cause corrosion.
• Lifted or loose lead: areas where the lead has lifted or become loose, and splits.
• Joints and seams: these are common places for leaks to develop.

What are the risks of a lead roof?

The main risks are theft, the weight of the material, health hazards when lead is worked, and environmental contamination.

Theft and vandalism

Lead is valuable, and its high market price makes it a target for theft and vandalism, particularly on unoccupied or remote properties. Theft can cause significant damage to the property and costly repairs.

Weight

Lead is heavy and puts additional stress on the roof structure. This matters most on older buildings that may not have been designed to carry such weight, where structural assessments and reinforcement may be necessary.

Health risks

The risk is greatest during installation, repair or removal of lead roofing, when prolonged exposure can pose serious health risks.

Environmental impact

Lead is a pollutant. Runoff from lead roofs can contaminate soil and water sources, posing a risk to wildlife and ecosystems. Proper disposal and recycling of lead materials reduces this impact.

How should a lead roof be maintained?

A lead roof should be inspected at least twice a year, ideally after winter and after summer, with prompt repair of any damage.

• Inspect: look for cracks, splits, sagging and areas where the lead has lifted or become loose, paying particular attention to joints and seams.
• Clear debris: keep the roof free of leaves, debris, moss and algae, which retain moisture and accelerate corrosion. Clearing debris also lets water drain off efficiently.
• Clean gently: use a soft brush or a low-pressure washer, avoiding harsh chemicals that can damage the lead.
• Ventilate: lead roofs need good ventilation to prevent moisture building up underneath.
• Repair promptly: small cracks or splits can be repaired, for example by lead welding. More extensive damage may need sections of lead replacing.
• Protective coatings: a coating can add a barrier against the elements and reduce the risk of corrosion, but only coatings specifically designed for lead roofing should be used, to avoid adverse reactions.

How much does a lead roof cost?

Lead is a premium roofing material and its installation cost can be higher than other roofing materials. On average, lead roofing can cost between £100 and £150 per square metre (figures given when this guide was first written). The cost varies with the size and complexity of the roof, the thickness of the lead and the quality of workmanship.

Lead roofs need less frequent maintenance than some other materials, but regular inspections and occasional repairs are still needed and should be budgeted for.

Does a lead roof affect insurance?

Because of the theft risk, the lead roof covering should be included specifically in the insurance policy, with cover against theft, vandalism and damage.

What regulations apply to lead roofing?

• Health and safety: strict regulations govern the use and handling of lead, requiring proper training and protective equipment for workers installing, repairing or removing lead roofing.
• Environmental: these cover proper disposal and recycling of lead and measures to prevent lead runoff contaminating soil and water.
• Building regulations: when a lead roof is installed, the building must be able to support the weight of the lead and the installation must meet all relevant standards.

What are the alternatives to lead roofing?

Zinc, copper, synthetic lead and slate are the main alternatives for those concerned about the risks and costs of lead.

What to look for when viewing

• Visible cracks or splits in the lead, particularly at joints and seams.
• Sagging areas, or lead that has lifted or become loose.
• Corrosion spots, or leaves, moss and debris collecting on the roof.
• Signs of missing lead or theft, particularly if the property has been unoccupied.
• Signs that an older roof structure is under stress from the weight of the lead.

What to do next

1. Check that the insurance policy specifically includes the lead roof covering and covers theft.
2. Arrange inspections at least twice a year and keep the roof clear of debris.
3. Have small cracks or splits repaired promptly, using workers with proper training and protective equipment.
4. On an older building, consider a structural assessment of whether the roof can carry the weight of the lead.
5. Budget for regular inspections and occasional repairs.

What a survey can — and cannot — tell you

A building survey provides an informed assessment of the visible condition of a property. Inspections are non-intrusive and limited to areas that are accessible at the time of inspection.

For a lead roof, a survey looks for the typical defects that lead to leaks and structural damage, so that a buyer can weigh the benefits of the covering against its risks and maintenance needs.

• Visible fatigue cracking, splits, sagging and corrosion spots.
• Lead that has lifted or become loose, and the condition of visible joints and seams.
• Build-up of debris, moss and algae.
• Visible signs of stress in the roof structure where it is accessible.

However, there are limitations to what a survey can determine without intrusive investigation.

• Moisture build-up beneath the lead cannot be confirmed without lifting it.
• Whether an older structure can safely carry the weight of the lead may need a structural assessment.

Where higher-risk indicators are identified, further specialist or intrusive investigation may be recommended.