How to Repair a Tar and Gravel Flat Roof: Step-by-Step Guide

If you’re not sure about how to repair a tar and gravel flat roof, it might seem daunting, but with the right steps, it can be manageable. Ensuring that damaged areas are clean and dry is crucial before applying any repair materials. Typically, one needs to identify leaks or cracks, remove debris, and clean the area thoroughly. Avoiding water damage requires thorough sealing with roofing cement and new gravel.

How to Repair a Tar and Gravel Flat Roof: Step-by-Step Guide

Tar and gravel roofs are popular for their durability and cost-effectiveness. Periodic maintenance is essential to prevent extensive damage. Inspecting the roof regularly for signs of wear and tear can save on larger repair costs.

It is much easier when using the proper tools and materials tailored for tar and gravel repair. With a few essential steps and some patience, restoring a flat roof to its former condition is entirely possible. Proper care and timely repairs will prolong the roof’s lifespan.

Understanding Tar and Gravel Roofs

Tar and gravel roofs, or built-up roofing (BUR) systems, are common for flat or low-slope roofs. They consist of multiple layers of materials, each serving an important function.

Components and Functionality

Tar and gravel roofs are made of alternating layers of tar or asphalt and roofing felt. These layers are topped with gravel or other materials to protect from UV rays and weather conditions.

The tar provides waterproofing, while the felt adds structural integrity. The gravel helps secure the layers, offering fire resistance and adding weight to keep the materials in place.

  • Layers: Tar, asphalt, or bitumen
  • Reinforcement: Roofing felt
  • Top Layer: Gravel, crushed rock, or slag

Benefits of Tar and Gravel Roofing Systems

Tar and gravel roofs are durable and long-lasting, often functioning well for 20 to 30 years. They provide excellent protection against weathering and UV rays. The gravel layer also adds an aesthetic element and can be walked on for maintenance purposes.

These roofing systems are cost-effective, offering a good balance of durability and affordability. They also provide good insulation, keeping buildings cooler in summer and warmer in winter.

  • Durability: 20-30 years
  • Protection: UV and weather
  • Cost: Affordable

Common Issues and Aging Signs

Over time, tar and gravel roofs can develop issues such as leaks and cracks. Common signs of aging include bald spots with missing gravel, pooling water, and cracks or blisters in the tar layer. Regular inspections can help identify and address these issues early.

Maintaining proper drainage is crucial to avoid water pooling, which can lead to deterioration. Timely repairs and maintenance extend the roofing system’s lifespan, preventing costly replacements.

  • Signs of Aging: Bald spots, pooling water, cracks, blisters
  • Maintenance: Regular inspections and timely repairs
  • Lifespan: Extended with proper care

Preparing for Repair

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Effective preparation is crucial to successfully repairing a tar and gravel flat roof. This involves gathering the right tools and materials, taking necessary safety precautions, and thoroughly inspecting the roof.

Tools and Materials Required

A thorough job requires specific tools and materials. Essential tools include a utility knife, a broom, and a sturdy bucket for debris. Materials typically consist of asphalt, rubber membrane patches, and gravel.

Make sure to have a trowel to spread asphalt evenly, and a roller to press down the membrane patches. Protective gloves and safety goggles are also vital to prevent injuries. Make a detailed list before starting to avoid unnecessary trips to the store.

Safety Precautions

Safety on the roof is paramount. Ensure the ladder is stable and positioned correctly. Wear non-slip shoes to prevent accidents. Safety harnesses can provide additional security, especially on sloped sections.

Be cautious when using tools like utility knives to avoid cuts. Always wear gloves and goggles to protect your hands and eyes from debris and chemical irritants. It’s best to work with a partner to have immediate help if needed.

Roof Inspection

Start by inspecting the roof for damaged sections. Look for areas where the gravel has worn away, revealing the asphalt beneath. Check for any cracks or signs of water pooling.

Use a broom to clear debris, ensuring you have a clear view of the surface. Pay special attention to the seams and edges where leaks are most likely to occur. Mark damaged areas with a chalk line for easier identification during repair.

Locating and Assessing Damage

Identifying and addressing damage on a tar and gravel flat roof is crucial to maintaining its integrity. Key aspects include pinpointing sources of leaks, evaluating the roof’s overall condition, and then deciding whether to repair or replace it.

Identifying Leak Sources

Finding the source of a leak on a flat roof can be challenging. Ponding water often points to low spots where water accumulates and leaks are likely to start. Check for visual signs of roof leaks, such as dark or discoloured patches, which indicate water damage.

Examine drain areas as well, since blocked or slow-draining sections can cause leaks. Rot and mould near any water entry points may also help to identify the leak’s origin. Using a water hose to test suspected areas can also be effective, turning up new leaks.

Evaluating Roof Condition

Evaluating the roof condition involves a thorough inspection. Look for bubbles or blisters, which suggest trapped moisture. The presence of mould or rot is another serious issue, indicating prolonged exposure to moisture.

Inspect the gravel layer to ensure it uniformly covers the tar; exposed tar can degrade quickly under UV rays. Check the structural condition of the roof, ensuring there are no sagging areas which could lead to further ponding water.

Walk the entire roof surface, feeling for soft spots that could indicate underlying water damage. Documentation of all findings with photos will assist in decision-making and future repairs.

Determining Repair or Replacement

Deciding whether to repair or replace largely depends on the extent and type of damage found. Minor flat roof leaks and patches of rot might only require spot repairs and possible re-gravelling. Extensive areas of damage, especially those involving structural issues or widespread mould, might necessitate a full replacement.

Consider the age of the roof; older roofs nearer the end of their lifespan are better candidates for replacement. Cost is also a factor, as sometimes a series of repairs can exceed the cost of a new roof. Consult with one of our professional flat roofers to get an accurate assessment and cost evaluation.

Repair Techniques

Repairing a tar and gravel flat roof requires careful attention to various issues such as holes, cracks, blisters, and drainage problems. Using the right materials and techniques ensures long-lasting repairs.

Fixing Small Holes and Cracks

To repair small holes and cracks, first clean the affected area to remove dirt and loose granules. Apply roof cement using a trowel for an even layer. For added reinforcement, use a piece of fibreglass fabric embedded into the cement. Cover with another layer of cement, ensuring the edges are well-sealed to prevent leaks.

Materials Needed:

  • Roofing cement
  • Fibreglass fabric
  • Trowel

Regular inspections help to identify small issues before they become major problems.

Handling Blisters and Delaminations

Blisters and delaminations occur due to trapped moisture or air. To fix this, cut open the blister, allowing the moisture to escape. Let it dry thoroughly. Apply a layer of roofing cement under the opened blister and press it back in place. Secure the edges with nails if necessary.

For added protection, coat the area with a liquid rubber coating, like EPDM or TPO.


  1. Cut open blister.
  2. Allow drying time.
  3. Apply cement underneath.
  4. Re-attach and secure.

Addressing Flashing and Edges Issues

Flashing and edge issues often lead to leaks. Examine the flashing for signs of wear or damage. Remove old or damaged flashing and clean the area. Install new flashing, ensuring it is well-secured with roofing nails. Seal the edges with roofing cement to provide a waterproof barrier.

Tools Needed:

  • Roofing nails
  • Hammer
  • Roofing cement

Consider using PVC flashing for long-lasting durability.

Dealing with Ponding and Drainage

Ponding water on a flat roof can lead to leaks and damage. Ensure all drains are clear and functioning. For low spots that cause ponding, build up the area using additional layers of roofing material or tapered insulation to direct water toward the drains.


  1. Clear drains.
  2. Identify low spots.
  3. Apply layers or insulation.

Regular maintenance of the drainage system is vital to keep the roof in good condition.

Upkeep and Prevention

Regular maintenance is key to extending the lifespan of a tar and gravel flat roof, and preventing future leaks requires proactive measures. Knowing when to seek professional help can save further damage.

Regular Roof Maintenance Tips

Maintaining a tar and gravel roof involves several important steps:

  1. Clear Debris: Removing leaves, branches, and other debris prevents water accumulation and potential damage to the roofing membrane.
  2. Inspect for Damage: Regular inspections help identify and repair small issues before they become major problems. Look for cracks, blisters, and loose gravel.
  3. Check Drainage: Ensuring proper drainage prevents water pooling, which can weaken the roof system and lead to leaks.
  4. Monitor Changes: Pay attention to changes in the roof’s appearance, such as sagging areas or new cracks.

Regular maintenance generally involves clearing debris, inspecting for damage, checking drainage, and monitoring changes in the roof structure.

Preventing Future Leaks and Damage

Key strategies for preventing leaks and damage include:

  • Limit Foot Traffic: Excessive foot traffic can wear down the roofing membrane. Only authorized personnel should walk on the roof.
  • UV Protection: Sunlight can degrade roofing materials. Apply reflective coatings to protect against UV rays and extend the roof’s lifespan.
  • Address Weather Damage: Hail and extreme weather can cause significant damage. After such events, inspect and repair any affected areas promptly.
  • Quality Repairs: Use proper materials and techniques for all repairs to maintain the roof’s integrity.

Preventive measures such as UV protection, minimizing foot traffic, and addressing weather damage help keep the roof in good condition.

When to Consider Professional Help

Professional help should be considered in these scenarios:

  1. Persistent Leaks: When leaks persist despite attempted repairs, professional intervention may be necessary.
  2. Large-scale Damage: Extensive damage from hail or other severe weather events often requires skilled repair.
  3. Complex Repairs: Some repairs, especially involving the roofing membrane, require specialized knowledge and tools.

Professionals ensure thorough and effective repairs, preventing further issues.

Advanced Flat Roofing Solutions

Advanced flat roofing solutions focus on implementing cutting-edge materials and sustainable, energy-efficient practices to enhance durability and reduce environmental impact.

Innovative Materials and Techniques

Employing modified bitumen offers increased flexibility and durability. Roofing contractors often apply this material using a trowel, ensuring precise installation. Polyvinyl chloride (PVC) and thermoplastic polyolefin (TPO) are other popular choices due to their weather resistance and long lifespan.

Roof membranes provide excellent protection against leaks. Roofing felt and metal flashing are used to reinforce edges and seams. Metal flashing enhances the structure’s integrity, preventing water intrusion. Roofing contractors often recommend combining multiple materials for best results, such as using tar and gravel roofing in conjunction with a modified bitumen layer.

Sustainable and Energy-Efficient Options

Sustainable roofing materials like TPO and PVC not only extend the roof’s life but also improve energy efficiency. These materials reflect sunlight, reducing cooling costs. Insulation plays a critical role in maintaining a building’s internal temperature. Using high-quality insulation materials minimizes energy consumption.

Roof replacements aimed at improving sustainability often incorporate recycled materials. Green roofs, featuring vegetation, provide natural insulation and reduce stormwater runoff. Additionally, incorporating sustainable practices, such as responsible disposal of old roofing materials, ensures minimal environmental impact during roof replacement.

The Professional’s Corner

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When considering flat roof repairs, focusing on hiring an experienced contractor and understanding the applicable warranties and insurance is crucial. These steps ensure the roof repair is cost-effective and long-lasting.

Hiring the Right Roofing Contractor

Choosing the right roofing contractor is pivotal for successful flat roof repairs. It’s essential to seek out a professional roofer with experience specific to tar and gravel flat roofs. Homeowners should ask for references and check reviews online, which we, at CD Roofing are happy to provide:)

Modern technology, like drones for inspections and infrared thermography, can add value to the assessment process. Contractors using advanced methods tend to deliver precise evaluations of roof damage, such as identifying standing water or deteriorated areas.

Request a written estimate detailing the scope of work, including the potential need for vent pipe boots or skylight repairs. An estimate should also mention any additional costs if a complete roof replacement is required.

Our contractors have regional experience, especially in dealing with natural disasters that could affect the roof’s integrity. This ensures they understand the local climate and common problems related to flat roofs.

Understanding Warranty and Insurance

Homeowners must scrutinize the warranties and insurance specifics when engaging a professional flat roof contractor. Verify whether the contractor offers a labour warranty alongside the manufacturer’s warranty on materials.

Comprehensive warranties should cover a range of issues from loose gravel to rubber roof repair needs. Different materials, such as single-ply roofs, may have varying warranty specifics. Knowing these details can prevent future disputes and additional costs.

Insurance plays a critical role as well. Ensure the contractor carries both liability insurance and worker’s compensation insurance to protect against potential accidents. This protects not just the workers, but also the homeowner and property from unintended damage or legal complications.

Check the policy specifics, such as r-value claims and coverage for roof damage due to UV rays. This understanding can help homeowners make informed decisions about who to hire and prepare for potential repair costs.

Frequently Asked Questions

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Repairing a tar and gravel flat roof involves specific steps, recommended products, and cost considerations. Understanding whether gravel is necessary and knowing the roof’s expected lifespan can also be crucial.

What steps are involved in repairing a tar and gravel flat roof?

The first step is to clean the roof surface thoroughly. Next, identify and remove any damaged gravel and tar. Apply a new layer of tar or roofing cement, followed by replacing or adding gravel to the repaired area.

What products are recommended for fixing a tar and gravel roof?

Quality roofing cement or bitumen should be used for the repair process. It is important to select roofing gravel that matches the existing gravel in size and type to ensure proper adherence and protection.

What are the alternatives to replacing a tar and gravel flat roof?

Alternatives include applying a new layer of tar and gravel over the existing roof, converting the roof to a single-ply membrane system, or using a modified bitumen roofing system. These alternatives can extend the roof’s life without a complete replacement.

How much does it typically cost to repair a tar and gravel roof?

The cost can vary based on factors such as the extent of the damage and the materials used. On average, repairs may range from $5 to $10 per square foot. It’s advisable to get multiple quotes from roofing professionals for accurate pricing.

Is it necessary to have gravel on a flat roof, and why?

Gravel helps protect the underlying tar from UV radiation, adds weight to prevent wind uplift, and provides an additional layer of protection against physical damage. It is a critical component of a tar and gravel roof system.

What is the expected lifespan of a tar and gravel flat roof?

A properly maintained tar and gravel flat roof can last between 20 to 25 years. Regular inspections and timely repairs are vital in extending its lifespan and ensuring its durability.