How to Repair a Cracked Lead Roof

Lead roofs are known for their durability and hardiness – that’s why they’ve lasted hundreds of years on churches and other historic buildings – but, unfortunately, they are not completely impervious to damage. Repairing a cracked lead roof quickly will be essential in preventing further and more serious damage to the property.

Here’s what you need to do to repair a cracked lead roof.

Identify the problem

The first step in any kind of roof repair is to identify the problem. Professionally installed lead roofs do allow for the natural movement caused by thermal expansion, but fatigue cracks or buckling can appear in lead roofs from continued expansion and contraction, usually over the course of 100 years or more. These cracks can quickly become big enough to allow water to ingress into the property, which can lead to further problems such as rot or structural damage to the roof rafters.

You should also keep an eye out for any corrosion of the lead which could indicate a lack of ventilation beneath the roof, and for a build-up of moss or algae which suggests an area of the roof that is subject to excessive moisture.

See if it needs repairing or replacing

Once you’ve identified the problem, you need to see whether it is repairable or if it is serious enough to require a roof replacement. Whilst most people may shudder at the thought of such a large job to put the problem right, a roof replacement (if necessary) will save a lot of money and headaches down the line when underlying issues would cause further and more significant damage.

Hopefully, if you catch the problem early enough, a repair should suffice. Small cracks may be able to be soldered shut, and it may be possible to weld a lead patch onto a cracked roof which is otherwise in good condition. 

Patching the cracked lead with other materials such as flashing or felt is a temporary solution that will protect the roof whilst you arrange a more substantial repair. Beware of bitumen or similar paints as these are very-short term solutions that can make the proper repair more difficult.

Is it a listed property?

If a property is listed, this will impact what work can be done on the roof. If you are using the proper matching materials and simply repairing damage such as a crack, you may not need any kind of Listed Building Consent. 

However, you will likely need this consent or planning permission if your repairs will in any way change the roof’s shape, pitch, height, or internal structure. Once you know the nature of the work that will need to be undertaken, contact your local authority to find out what kind of permission is required.

Get the help of a professional roofer

Once you have identified the problem, the necessary method of repair and any planning permission required, you should get the help of a professional roofer who specialises in lead roofs. They will be able to strip the slates and re-lead them in a safe way. It is worth noting that not all roofers will be capable of this if they are not leadwork specialists, as this trade takes years to master. If you need help inspecting the roof and identifying the problem to begin with, a professional roofer will be able to assist you with this too.

Hopefully, this has been helpful in informing you about what is involved in repairing a cracked lead roof. Remember to always turn to a professional if you have any doubts about the roof repairs you need to undertake, and one that specialises in leadwork if your problem is with a lead roof.

You can see our full list of roofing services, including specialist lead roofing services, or get in touch with us for further details.