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Common Causes of Premature Slate Roof Failure

Slate roofs are famous for their durability and longevity, but they can fail prematurely if not managed correctly. This article will explore common reasons for early slate roof problems and offer straightforward steps to prevent and fix these issues.

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A Homeowner's Guide to Slate Roof Preservation

A well-built slate roof is a crowning glory of many homes, admired for its natural elegance and longevity. Yet, even the sturdiest slate can succumb to problems if not looked after properly. In this guide, we'll uncover the typical challenges that homeowners may face with slate roofing. From installation woes to the ravages of time and weather, we'll navigate through each concern, providing you with practical advice to safeguard your roof. 

Whether you're addressing minor issues or major repairs, this article will arm you with the knowledge to keep your slate roof in peak condition, ensuring it stands the test of time.

Improper Installation Techniques

A slate roof has to be installed with precision. Mistakes like uneven slate alignment or inadequate overlapping can cause leaks. It's important to ensure that whoever installs your roof is experienced and pays attention to detail, using the right techniques and tools.
For example, if the slates are not laid with an adequate headlap (the overlap of slate tiles), water can seep underneath, leading to leaks. A headlap of at least 3 inches is standard for most regions.
a poorly installed slate roof with overlapping slates
another example of a badly installed slate roof that needs to be repaired properly
"80% of the new slate roofs I'm called out to inspect have installation problems, improper head lap, improper side lap, or incorrect nailing."
- John Chan, CEO

Inadequate Roofing Support and Structure

Slate roofs are heavy. If the structure underneath isn’t strong enough, it can lead to a sagging or collapsed roof. It's crucial to have a professional check that your building can support the weight before installation.
An example of this would be an older home where the original wooden structure has weakened over time, leading to a sagging roof. This requires assessment and potential reinforcement before a heavy slate roof can be safely installed.
chinese black slate rusting out
chinese black slate rusting out
"Make sure you have your roofing contractor and/or an engineer inspect your structure, before replacing your roof with slate if it's not currently slate."
- John Chan, CEO

Inferior Slate Quality

Good slate should resist the elements and last for decades. Some slates are soft and may flake or delaminate after exposure to the weather. Always choose slate from trusted sources and don’t compromise on quality for cost.
For instance, some slates may look intact upon installation but can start to crumble within a few years if they are of poor quality. True high-grade slate should last well beyond a decade without showing signs of significant wear.
chinese black slate rusting out
example of chinese multicolored slate rusting out after only five years of roof use
"Most slate roofs are purchased through distribution, and usually distributors just buy in bulk from quarries, put their mark up on it and sell it. Unfortunately, slate isn't like other roofing materials. Copper is uniform, for instance -16 ounce or 20 ounce, etc. Shingles are manufactured in a plant with certain specifications. Slate is a natural product that is quarried from the deep in the ground. One has to understand slate quality when installing a slate roof system."
- John Chan, CEO

Weather-Induced Damage

Slate roofs, renowned for their resilience, are nonetheless susceptible to weather-related damages. Hailstorms, for instance, can subtly crack slates, leading to potential leaks. 

Similarly, strong winds might dislodge or shift tiles, causing gaps that allow water to seep in. Regular inspections, particularly after severe weather events, are essential to identify and rectify such damages promptly.
For example, after a severe hailstorm, a slate roof might suffer from broken or cracked tiles that need immediate replacement to prevent leaks.
obvious hail damage to a slate roof
example of badly installed slate roof damage
"Different parts of the country have drastically different weather conditions. The Gulf Coast areas can have Hurricane force winds, The Midwest is susceptible to large hail, the North East is often hit with heavy snow."
- John Chan, CEO

Faulty Flashing and Leadwork

Waterproofing is vital for a slate roof’s longevity. Flashing—the metal strips that seal transitions on a roof—must be correctly installed. Check the flashing regularly for any signs of damage or wear and replace it when necessary.
An example here might be the corrosion of flashing around a chimney, which could allow water to enter the home. Replacing this flashing would stop further water damage.
a bad chimney repair without copper flashing and leaks
New slate roof without copper flashings
"Make sure you have your roofing contractor and/or an engineer inspect your structure, before replacing your roof with slate if it's not currently slate."
- John Chan, CEO

Moss and Lichen Growth

Organic growth can trap moisture against the slate, leading to decay. Keep trees trimmed back from your roof to reduce shade and moisture. Regularly cleaning your roof can also prevent growth and keep your slates in good condition.
Consider a slate roof shaded by large trees; it's often prone to moss growth. The removal of overhanging branches and the application of anti-moss treatments can prevent this.
chinese black slate rusting out
chinese black slate rusting out
"Make sure you have your roofing contractor and/or an engineer inspect your structure, before replacing your roof with slate if it's not currently slate."
- John Chan, CEO

Best Practices for Preventing Premature Failure and Resolving Slate Roof Problems

Regular Inspections and Maintenance

A slate roof should be seen as a long-term investment, and like any investment, it requires regular attention to maintain its value. Annual or biannual inspections are vital, particularly after heavy storms or freezing temperatures, which can crack or dislodge slates. 

For example, The Durable Slate Company might find during a routine check that some slates have shifted slightly after a winter storm. By repositioning these slates and securing them, we can prevent water ingress that would lead to costly internal damage. This proactive approach not only preserves the integrity of the roof but also maintains the aesthetic appeal of your home's exterior.

Immediate Repairs vs. Major Overhauls

When a problem is identified, deciding whether to repair or replace can be challenging. Immediate repairs are often sufficient for minor issues, such as replacing a broken slate or resealing flashing. However, when multiple areas of the roof are affected, it might be time for a major overhaul. 

For example, if The Durable Slate Company is called to a home where the roof has multiple leaks, damaged battens, and widespread slate deterioration, we may recommend a comprehensive restoration. This would not only address the visible damage but also fortify the roof's underlying structure, ensuring the roof's longevity and performance.

Professional Slate Roof Servicing

The intricacies of slate roof repair require a level of expertise that goes beyond general roofing knowledge. Professionals like those at The Durable Slate Company specialize in identifying and resolving unique slate roofing issues. For example, we might detect that a seemingly minor leak is actually the result of a subtle misalignment of the slates, invisible to the untrained eye. With our specialized knowledge, we can correct this issue swiftly, avoiding the potential for more significant damage. Our expertise ensures that repairs are not just temporary fixes but are comprehensive solutions that blend seamlessly with the existing roofing structure.

In each of these examples, our role is to provide not just a service, but a partnership in preserving the heritage and functionality of your slate roof. Through diligent inspections, adept handling of repairs, and a deep understanding of the material, we offer a trusted solution to maintaining the classic beauty and durability of your slate roofing.
More than a roof.