Knowledge Centre
What is Nail Sickness?
MF Roofing Explains the Hidden Threat to Your Slate Roof
At MF Roofing, we’ve worked on slate roofs across Scotland for decades. We’ve seen how these elegant, durable roofs can last over a century when properly maintained. But even the most beautiful slate roof can be quietly undermined by a hidden issue: nail sickness.
Nail sickness is one of the most common causes of premature slate roof failure, especially in older properties. It’s not about the slate itself—it’s about the nails that hold the slates in place. And when those nails fail, the entire roof is at risk.
In this post, we’ll explain what nail sickness is, why it happens, how it affects your roof, and what you can do to prevent or fix it. Whether you’re a homeowner, property manager, or just someone interested in roof maintenance, this guide will help you understand how to protect your investment.
What is Nail Sickness?
Nail sickness refers to the corrosion or deterioration of the nails used to fix slate tiles to your roof. Over time, these nails—especially if made from iron or mild steel—can rust, weaken, and eventually fail. When that happens, the slates they hold can slip, loosen, or fall off entirely.
This issue is particularly common in older roofs, many of which were constructed using iron nails. While the slate itself may still be in excellent condition, the nails may have reached the end of their lifespan.
Why Does Nail Sickness Occur?
At MF Roofing, we’ve identified several key causes of nail sickness:
1. Material Degradation
Older roofs often used iron or low-grade steel nails, which are highly prone to rust. Once corrosion sets in, the nails lose their grip and the slates become unstable.
2. Moisture and Weather Exposure
Roofs are constantly exposed to rain, snow, and humidity. Moisture seeps into nail holes and accelerates corrosion, especially in poorly ventilated roof spaces.
3. Environmental Conditions
In coastal areas, salt in the air can speed up the corrosion process. Similarly, pollution in urban environments can contribute to chemical reactions that degrade metal faster.
4. Age and Construction Style
Many older properties were built with single-nailed slates, meaning each slate is held in place by just one nail. This makes them more vulnerable to nail sickness. At MF Roofing, we always double-nail slates for added strength and longevity.
How Nail Sickness Affects Your Roof
Nail sickness can quietly compromise your roof’s integrity. Here’s how it typically unfolds:
1. Slipping or Missing Slates
As nails corrode, they lose their grip. Slates may begin to slide out of place or fall off entirely, especially during high winds or storms.
2. Water Ingress
Gaps left by missing slates allow water to penetrate the roof structure. This can lead to leaks, damp patches, and even rot in the timber framework.
3. Structural Damage
Persistent water ingress can damage the battens and rafters beneath the slates. Over time, this weakens the structural integrity of the roof and can lead to costly repairs.
4. Reduced Roof Lifespan
Even if your slates are in good condition, nail sickness can force a premature roof replacement—sometimes decades earlier than expected.
Signs of Nail Sickness
You don’t need to be a roofing expert to spot potential nail sickness. Look out for:
- Slates that appear to be slipping or missing
- Rust stains on slates or under the eaves
- Rattling noises from the roof in windy weather
- Water stains on ceilings or in the loft
- A roof over 50 years old that hasn’t been inspected recently
If you notice any of these signs, it’s time to have your roof checked.
Repairing Nail Sickness
Depending on the extent of the damage, we offer several solutions:
🔧 Spot Repairs
We replace individual slates and re-nail them using copper nails only—never iron or steel. Copper is naturally resistant to corrosion and ensures long-term durability.
🧰 Partial Re-nailing
If the issue is limited to a section of the roof, we can lift the slates, replace the nails, and re-lay the slates. This is often a cost-effective way to extend the life of your roof.
🏗️ Full Strip and Re-slate
If nail sickness is widespread, we may recommend removing all slates, replacing the nails and battens, and reinstalling the slates. If the slates are still in good condition, we can often reuse them—preserving the character of your home while giving your roof a new lease on life.
Preventing Nail Sickness
While you can’t stop time, you can take steps to delay or prevent nail sickness:
- Use Quality Materials: At MF Roofing, we only use copper nails in all our work—no exceptions.
- Double-Nailing for Strength: Unlike older roofs that were often single-nailed, we double-nail every slate for added security and resistance to wind uplift.
- Schedule Regular Inspections: Catching issues early can save you thousands in repairs.
- Maintain Proper Ventilation: Good airflow in your loft helps reduce moisture buildup.
- Act Early: Don’t wait until slates start falling—early intervention is key.
MF Roofing’s Inspection Services
To help homeowners stay ahead of issues like nail sickness, we offer two levels of professional inspection:
🔍 Roof Survey – £60
This is a visual inspection designed to identify quick repairs and spot visible issues. It takes 30 to 60 minutes and is ideal if:
- You’ve noticed a few slipped slates
- You want a quick check after a storm
- You’re buying or selling a property
We’ll assess the condition of your slates, look for signs of nail sickness, and highlight any immediate concerns.
🏠 Full Roof Inspection – From £400
This is a comprehensive inspection suitable for insurance purposes or when you want a complete understanding of your roof’s condition. It takes half a day and includes:
- A full external inspection of the roof
- An internal inspection of the loft space
- Assessment of slate condition, nail integrity, battens, underlay, and ventilation
- A detailed report with recommendations
This is the best choice if:
- Your roof is over 40–50 years old
- You suspect widespread nail sickness
- You need a detailed report for insurance or renovation planning
Final Thoughts: Don’t Let Nail Sickness Catch You Off Guard
Nail sickness is a silent threat that can turn into a major problem if left unchecked. But with regular inspections, high-quality materials, and expert care, you can extend the life of your slate roof and avoid costly surprises.
At MF Roofing, we’re here to help. Whether you need a quick survey or a full inspection, we’ll give you honest advice and expert service—backed by decades of experience and a commitment to craftsmanship.
📞 Call MF Roofing on 01738 314551
📧 Email us at [email protected]
🌐 Visit www.mf-roofing.co.uk to book your Roof Survey or Full Inspection
Let’s protect your roof—before nail sickness becomes a bigger problem.
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Outstanding service. Thorough examination of the issue and everything explained clearly and in detail. Can't be faulted.
I have used MF Roofing over many years. Usually on a annual basis for a "check up" on my roof before the usual bad Scottish weather arrives.
I have always found MF Roofing to be excellent in every way as well as helpful in any advice they care to give along with time taken to explain where wanted exactly what & why they consider any work advisable.
I have no hesitation in recommending MF Roofing to others (which I have done) but also in continuing to use their services
Matthew and his team were phenomenal from start to finish. They guided me through the works and proposals in a detailed manner and kept me updated at all times during it. The end result has been perfect.
I'm incredibly happy and fully recommend anyone looking for quality roof works to reach out to MF Roofing.
Very friendly and competent.
First class service from this company, speedy repair to a leak in my roof. Mathew took photos to show me what the problem was. Repair done and gutters cleared out . Polite , fast and very efficient.
So easy to book an appointment and arrived on time. Very approachable and informative. I feel very confident in their abilities. Highly recommended.
Matthew and his team did an excellent job renovating the chimney and fixing various other issues on our 125 year old roof. Everything required was clearly explained after the initial survey and work was done to a high standard. The guys we met were friendly, polite and respectful of our home. I can be a tad pernickety but everything was taken on board and dealt with professionally. We highly recommend and will be confident to use their services again. Many thanks.
Fab roofers Totally trustworthy and always the highest standard. Thankyou to Matthew and his team
We used MF Roofing to carry out some work on our roof due to bad weather. They were very quick and friendly in responding, and they carried out the work on our roof to a high standard (excuse the pun). I would highly recommend them and would definitely use them again in the future if need be!
Cannot fault MF Roofing! They tiled the roof for our new build. Yvonne and Matthew are very quick to respond to emails and have been extremely helpful throughout the whole process, which was quick and seamless. Matthew is very knowledgeable and passionate about his work. Despite the complex design of the roof and very challenging weather conditions, BJ and colleagues have completed a highly professional job and should be proud of their work ethic. We are delighted with the finished job and cannot recommend them enough!
Just had MF Roofing complete a repair on my lead roof valley. The job was completed quickly and cost effectively. After contacting numerous roofers I found MF roofing the most honest and straightforward to deal with and having the best pricing in the Perth area. I highly recommend for anyone who needs roof work.
Very professional and reasonably priced. The guys were really polite and got the job done ,even working in the atrocious weather we had. Would certainly use this company again and recommend to family and friends
Extremely responsive and performed challenging repair work in difficult conditions. Tidy and professional. Compares extremely well with other roofers we've used over the years.
Just brilliant service. Matthew laid our slate roof a few years ago, and it was really important that we went back to him for a couple of repairs. Such a craftsman and so passionate about his work. Great service, repairs carried out promptly, left the area very clean and tidy. First-class!
Delighted with the standard of service we received from Matthew and the team! Incredibly prompt response to our enquiry and an excellent job done in checking over all our roof tiles and making good any repairs required. A really nice bunch of guys to have around the house too - very positive and professional. We have no problems in recommending their services and would definitely use them again. Thanks so much- Paul & Debbie Wheeler.
Great service, roof was damaged in recent storms and MF Roofing came out straight away and dealt with it very professionally and at a good price. I would definitely use them again.
would highly recommend MF Roofing had a tile come off roof due to the storm, MF roofing came same day i phoned which was on a sunday to look at it and came back job done by tuesday, and v helpful with advice about the roof. would definitely use again.
Brilliant service from the guys did a roof repair when storm arwen hit. Very quick emergency repair and will definitely be using them again.very professional team with great value cost.
The 2 gentlemen that did our work was absolutely superb. Manners helpfulness were all fantastic. They were a credit to themselves . From start to finish superb. Highly recommended yours mr & mrs rushforth
Matthew and his team did a fantastic job. I actually got my roof replaced about 4 years ago and it looks as good now as the day they finished. Haven't experienced any problems and I am sure if I do Matthew will respond promptly as he always responded to any queries I had at the time.
I highly recommend MF Roofing. They did really good job and for a reasonable price. They also were quick and profesional. Thanks so much guys!
Came to look at leaking roof and explained what work required to be carried out and would send quote. That was on 4th October and I have tried contacting him by text , e mail and messenger but to no avail and even asked if he could recommend another roofer if he was too busy to carry out my roof repairs but no response.
I highly recommend Matthew of MH Roofing, he was very responsive , gave me good advice and fixed my problem the same day as I called him out. He also gave me a good price for the work done.
Delighted with the standard of service we were given.
Matthew Farmer is a craftsman. His lead work and slate work is outstanding and his team are polite and punctual. I couldn’t recommend Matthew Farmer Roofing more highly! We simply couldn’t be happier! The lead work is exceptional and we will recommending your service to everyone we know!
A great job done, really pleased. Friendly, professional, knowledgable, trustworthy. Would use again and definately recommend.
So delighted with my experience with MF Roofing! I saw Matthew’s post about doing emergency repairs for NHS workers, I messaged him and he arrived the next morning at 9am! He was knowledgeable, helpful, friendly, and efficient. I would absolutely recommend this business. Thanks so much MF Roofing!
Cannot fault MF Roofing. Would highly recommend.
Matthew is a really lovely, honest guy. Very professional and communication was great - very quick response and fixed my roof tile with ease.
Would absolutely use again.
Great to have trusted tradesmen.
MF Roofing was well recommended to me, hence I entrusted them with a roofing task, which was causing water ingress. The problem was soon identified and swiftly and professionally dealt with. From start to finish the response & service was simply first class. Simply delighted. JD
Great job repairing some storm damage. Quick response, high standard of workmanship. Very professional
Fixed my Mums leaky roof. Did an excellent job, after identifying the problem ( which was in a tricky place) they fixed it very quickly and efficiently. Thanks again
5 stars
Great guy running a great company. Was a pleasure working for MF Roofing.
5 stars