Flat Roofing Specialists

Flat garage roofs are often taken for granted until problems begin to show. In coastal areas like Folkestone and the wider Kent region, constant exposure to wind, rain, and salt air can quickly accelerate deterioration. This recent project in Cheriton involved a complete single garage flat roof replacement after severe water ingress had caused extensive rot to the existing structure.

The property sits within a row of adjoining garages, a common setup across many residential estates in Kent. Over time, the original roof covering had failed completely, leading to persistent leaks and internal timber decay. A full strip and rebuild was required to restore the structure properly and ensure long-term waterproofing.

Overview of the Work

This project involved a full removal and replacement of the existing flat garage roof, including all failed materials and structural timbers. The work was carried out by The Flat Roofing Specialist, a Folkestone-based roofing company known for delivering reliable, long-lasting flat roofing solutions across Kent and the Southeast.

The scope of works included:

• Complete strip-off of existing felt, boards, and rotten joists
• Installation of new structural timber joists
• New roof decking installation
• Two-layer torch-on felt roofing system with mineral cap sheet
• Weather-sealing across adjoining garage roof sections
• Full waste removal and site clearance

Common Problems with Old Flat Garage Roofs

Flat garage roofs, particularly older felt systems, are highly susceptible to failure once they reach the end of their lifespan. In many cases, homeowners notice issues only after internal damage has already occurred.

Typical problems include:

• Cracking and blistering of old felt membranes
• Ponding water due to poor drainage or sagging timber
• Rotten roof joists caused by long-term leaks
• Separation at joints between adjoining garage roofs
• Repeated patch repairs that no longer hold

In this case, the damage had progressed to the point where a full replacement was more cost-effective and structurally necessary than ongoing repairs.

What We Found on Site

On inspection, the garage roof showed significant signs of long-term water ingress. The felt system had completely failed, and once removed, the underlying boards and joists were found to be heavily rotted.

This level of deterioration is common in older flat roof structures where water has been allowed to penetrate over time. Once timber becomes saturated and weakened, it can no longer safely support the roof covering, making full replacement essential.

Our Approach to the Replacement

Careful Strip Off

The first stage involved safely removing all existing roof layers, including felt, roof boards, and structural joists. Due to the extent of decay, none of the original materials were suitable for reuse.

Structural Timber Replacement

New treated timber joists were installed to form a strong and level structural base. Ensuring correct spacing and alignment is essential for long-term performance, particularly in exposed coastal areas like Folkestone where wind uplift can be a factor.

New Decking and Torch-On Felt System

Once the new structure was in place, high-quality roof decking was installed to create a solid base for the waterproofing system. A professional-grade torch-on felt system was then applied, consisting of two layers of underlay and a durable mineral cap sheet finish.

This system is widely regarded as one of the most reliable flat roofing solutions available, offering excellent resistance to water, UV exposure, and general weathering.

Weatherproofing Between Adjoining Garages

As the garage sits between neighbouring units, special attention was given to sealing the junctions. The new waterproofing was carefully overlapped onto adjacent garage roofs to ensure a continuous, watertight finish and eliminate any weak points where leaks could develop in future.

Why Flat Roofs Fail in Coastal Kent

Areas like Folkestone, Hythe, and the wider Kent coastline experience harsher-than-average weather conditions compared to inland regions. High winds, driving rain, and salt-laden air all contribute to accelerated roof deterioration.

Flat roofs are particularly vulnerable when:

• They are not regularly maintained
• Drainage becomes blocked or inefficient
• Old felt systems reach the end of their service life
• Timber structures are exposed to prolonged moisture

This makes regular inspection and early intervention essential for preventing costly structural damage.

Materials Used and Why They Matter

For this project, a traditional torch-on felt system was selected due to its proven durability and suitability for garage roofs.

The system included:

• New structural treated timber joists
• OSB roof decking for a stable surface
• Two-layer torch-on felt system
• Mineral cap sheet for UV and weather protection

This combination provides a strong, weather-resistant finish designed to perform well in both residential and exposed coastal environments.

Signs You May Need a Flat Roof Replacement

It is not always obvious when a flat roof has reached the end of its life. However, there are several warning signs homeowners should look out for:

• Persistent leaks or water stains inside the garage
• Visible cracks, bubbles, or splits in the felt
• Sagging or uneven roof surfaces
• Rotten or damp timber around the roof edges
• Repeated repairs that fail to resolve the issue

If any of these signs are present, it is often more economical in the long term to consider a full replacement rather than ongoing patch repairs.

Aftercare and Waste Removal

Once the installation was complete, all waste materials were removed from site and disposed of responsibly. The area was left clean, tidy, and safe, with the new roof fully finished and ready to perform immediately.

Final Result

The completed garage roof now provides a fully waterproof, structurally sound solution designed to withstand the challenging coastal conditions found across Kent. By replacing both the structural timbers and waterproofing system, the property has been fully protected against future leaks and deterioration.

Free Survey and Advice

If you have concerns about a flat garage roof, extension roof, or any other flat roofing system in Folkestone or the surrounding areas, The Flat Roofing Specialist offers free surveys and honest, no-obligation advice.

We provide clear recommendations on whether repair or replacement is the best option, always focusing on long-term value and reliability rather than short-term fixes.

For expert help with flat roof repair in Folkestone or across Kent, get in touch today to arrange a free inspection.

Customer Google Review
Did a great job would recommend them to anyone looking for flat roof repairs. Read Reviews