Why Is My Lead Roof Leaking? Common Failures I See in Sussex

Lead is a fantastic roofing material – it can last for over a century if it’s installed correctly. But when I’m up on a roof in Brighton or Worthing, I see the same old problems causing leaks. The number one culprit is thermal movement. Lead expands in the summer heat and shrinks in the winter cold. Over many years, this constant movement causes stress, which eventually leads to splits and cracks, especially if the original installer used pieces that were too large or didn’t secure them correctly.

Other common causes include:

  • Poor Installation: Using the wrong fixings, not allowing for expansion, or incorrect overlaps (laps) will guarantee failure.
  • Age & Thinning: Over decades, the lead can simply wear thin, becoming brittle and prone to cracking.
  • Punctures: Dropped tools, foot traffic, or even a poorly placed ladder can easily puncture an old lead roof.

Can I Repair a Split in a Lead Roof Myself?

Here’s the brutally honest answer: yes, you can patch it for a very short time. You can go to a DIY shop and buy a tin of bitumen paint, flashing tape, or a fibre-reinforced goo like Acropol. Slap it over the crack, and it might stop the leak for a few weeks, maybe even a few months if you’re lucky.

But let me be absolutely clear: this is a temporary bodge, not a repair. The lead underneath will continue to expand and contract, and that patch will quickly fail, crack, and peel away. You’ll be back to square one, but now you have a sticky, messy black patch on your roof that makes a proper, professional repair more difficult and expensive. It’s a classic false economy.

How Do You Properly Repair a Lead Roof?

The only correct, long-term way to repair a split in lead is through lead welding (often called lead burning). This involves using an oxy-acetylene torch to fuse a new piece of lead over the damaged area, creating a seamless, permanent, and completely waterproof joint. There are no sealants, no glue, no sticky tape – just lead fused to lead. This process requires specialist equipment and a lot of skill to do without damaging the surrounding roof structure.

For larger areas of failure, the best course of action is often to cut out the damaged section and weld in a new, correctly sized piece of lead, ensuring the fixings and laps are done to the highest standard. This is how you get another 50+ years out of the roof, not just another 5 months.

When Should I Replace vs. Repair My Lead Roof?

The decision comes down to the overall condition of the lead. If you have a single, isolated split on an otherwise thick and healthy lead roof, a welded repair is the most sensible and cost-effective solution. I handle these sorts of professional leadwork repairs all the time.

However, if the lead is thin all over, has multiple splits, or shows signs of being poorly installed in the first place (what we call ‘over-baying’), then patching it up is like putting a plaster on a broken leg. In these cases, a full replacement is the only logical choice to prevent constant, recurring leaks. It’s a bigger initial investment but saves you money and stress in the long run.

Is It Lead Roofing or Lead Flashing?

People often use these terms interchangeably, but they are different. Lead roofing is when the entire surface is covered in lead – common on bay windows, porches, and dormers. Lead flashing, on the other hand, refers to the pieces of lead used to weatherproof the joints on a roof, such as where a chimney meets the tiles or at the abutment to a wall. While the material is the same, flashing is a component, not the whole roof – though it’s arguably the most important one (it’s a vital part of any pitched roof system). It performs a similar job to other flat roof coverings but with far greater longevity.

My Lead Roof Is Leaking Right Now in Hove! What Should I Do?

First, don’t panic. Place a bucket under the drip to protect your property inside. Second, do not be tempted to climb up there in the rain to apply a DIY patch – it’s dangerous and won’t work properly on a wet surface. Your priority is to get a professional to look at it as soon as possible.

If you have an active leak causing damage, your best bet is to get an urgent leak repair sorted immediately. A temporary fix can be put in place by a professional to stop the water ingress, followed by a permanent solution once the weather improves.

If you’re unsure about the state of your leadwork or have a slow, niggling leak, the best first step is to get it properly assessed. I can tell you exactly what the problem is and what it will take to fix it properly. I provide fixed-price quotes, so you know the exact cost upfront, and a client portal with daily photo updates so you can see the quality of the work yourself. Don’t let a small split turn into a major disaster – book a free, no-obligation inspection today and get an honest assessment from me personally.