Asphalt roll roofing is a practical, cost-effective solution for low-pitch roofs such as those found on sheds, gazebos, garages, and three-season rooms. This material is thinner and more flexible than traditional asphalt shingles, making it easier for experienced DIYers to handle and install. However, successful installation requires careful preparation, precise measurements, and proper sealing techniques.
This article provides step-by-step instructions, material recommendations, and best practices based on official guidance from roofing experts and technical resources. It also highlights key considerations such as weather conditions, tool preparation, and optional underlayment use to ensure a durable and long-lasting installation.
Overview of Asphalt Roll Roofing
Asphalt roll roofing is a flexible, lightweight roofing material composed of a base fabric saturated with asphalt. It is commonly used for low-pitch roofs where traditional shingle installation may be impractical. The material is available in rolls that are typically 35 feet long and 35 inches wide, though it can be cut into smaller sections to fit specific roof dimensions.
Roll roofing is appropriate for structures with minimal roof slope, such as sheds, gazebos, patios, and outdoor structures. It is not recommended for steep-pitch residential roofs, where other materials like asphalt shingles or metal roofing are more suitable.
One of the key benefits of roll roofing is its ease of installation. With the right tools and materials, most DIYers can complete the process without professional assistance. However, proper preparation and adherence to installation guidelines are essential to ensure longevity and performance.
Materials and Tools Required
Before beginning the installation, it is important to gather all necessary materials and tools. The following items are typically required for a successful roll roofing project:
Materials
- Roll roofing material: Sufficient quantity to cover the entire roof surface, with an additional 5% to 10% for trimming.
- Roofing cement: Used to adhere the roofing material to the roof surface and seal edges and seams.
- Roofing nails: For securing the roofing material in place.
- Roofing felt (optional): An underlayment that provides an extra layer of protection against moisture and improves insulation.
- Flashing (if needed): Metal flashing may be required for vulnerable areas such as valleys, edges, or roof penetrations.
Tools
- Measuring tape
- Chalk line
- Utility knife or razor knife
- Hammer
- Trowel (for spreading roofing cement)
- Ladder
- Broom or leaf blower
- Heavy objects (e.g., bricks) to hold down the roofing material
Preparing the Roof Surface
A clean, dry, and stable roof surface is essential for a successful roll roofing installation. Before applying the roofing material, follow these steps to prepare the surface:
Clean the Roof
Remove all debris, dirt, and loose material from the roof using a broom, leaf blower, or hose (from a safe area). A clean surface ensures that the roofing material adheres properly and reduces the risk of air pockets or bumps under the roofing.
Make sure the roof is completely dry before proceeding with installation. Moisture can interfere with the adhesion of the roofing cement and compromise the integrity of the installation.
Inspect for Damage
Carefully inspect the roof sheathing or decking for any signs of damage, such as rot, loose boards, or cracks. Replace any damaged sheathing to create a solid, reliable base for the roll roofing.
Optional: Apply Roofing Felt
For added protection against moisture, consider installing a layer of roofing felt as an underlayment. Secure the felt with roofing nails or staples, following the manufacturer’s instructions. This step is optional but recommended for improved durability and weather resistance.
Mark the First Row with Chalk
Measure 35 inches up from the bottom edge of the roof and use a chalk line to mark a straight guide for the first row of roll roofing. This line ensures that the rows will be aligned and even, contributing to a uniform and secure installation.
Install Metal Flashing (If Needed)
If the roof has vulnerable areas such as valleys, edges, or roof penetrations (e.g., chimneys, vents), install metal flashing to create an extra barrier against water. Flashing should be attached with roofing nails and sealed with roofing cement at the edges.
Installing the Roll Roofing
With the roof surface prepared and all materials and tools gathered, you can begin the installation process. Follow these steps carefully to ensure a secure and durable result.
Step 1: Unroll the Roofing Material
Unroll the roofing material on the ground to relax any curl in the material and make it easier to handle. If the material tends to roll back up, use heavy objects (e.g., bricks) to hold the corners in place. This makes it easier to work with the material while on the roof.
Step 2: Apply Roofing Cement
Apply a thin layer of roofing cement (1/8 to 1/4 inch thick) along the edges of the roof where the first row of roll roofing will be placed. Use a trowel to spread the cement evenly. This helps the roofing material adhere securely and creates a watertight seal.
Step 3: Cut the Roll Roofing
Using a utility knife, cut the roll roofing to fit the roof sections. It is important to measure twice and cut once to avoid wasting material. Each section should be at least 35 inches wide to align with the chalk line when installed.
Step 4: Install the First Row
Position the first piece of cut roofing material along the chalk line. The other edge of the roll should align with the outer edge of the drip edge. Carefully lay the material down, pressing it into the wet cement as you go. This helps secure the roofing and stretches out any wrinkles.
Drive roofing nails along the bottom edge and sides of the first row. Nails should be placed 1 inch from the edges and spaced 6 to 10 inches apart, depending on the roof’s size and condition. After nailing, apply roofing cement over the nails to seal them in place.
Step 5: Continue with Additional Rows
Repeat the process for additional rows, overlapping each row by 4 to 6 inches to ensure proper coverage and water resistance. Each row should be aligned with the previous one to maintain a uniform appearance and secure installation.
As you work your way up the roof, continue applying roofing cement and nails to secure each row. Make sure to press the material firmly into the cement and smooth out any wrinkles or folds.
Step 6: Seal Edges and Seams
Once all rows are installed, apply roofing cement along the edges and seams of the roofing material to ensure a watertight seal. Pay special attention to vulnerable areas such as corners, valleys, and roof penetrations.
Step 7: Final Inspection and Cleanup
After installation is complete, inspect the roof for any gaps, wrinkles, or improperly sealed areas. Make any necessary adjustments and ensure that all nails are covered with roofing cement.
Remove any excess materials and tools from the roof surface. A clean and well-maintained roof surface contributes to the longevity of the roll roofing.
Weather and Safety Considerations
Proper weather conditions are essential for a successful roll roofing installation. It is recommended to choose a day when the temperature is at least 50°F. Cold weather can make the material stiff and brittle, increasing the risk of damage during installation.
Additionally, safety should be a top priority. Ensure that the ladder is secure and placed on a stable surface. Wear appropriate safety gear, including gloves and eye protection, to prevent injuries from sharp tools or debris.
Common Questions and Considerations
Can Roll Roofing Be Installed Over Existing Shingles?
Roll roofing can be installed over existing shingles in some cases, but it is generally recommended to remove the old shingles first. If removal is not feasible, make sure to remove gravel, slag, and debris from the existing roof to avoid puncturing the new roll roofing.
What Are the Advantages of Roll Roofing?
Roll roofing offers several advantages, including ease of installation, cost-effectiveness, and suitability for low-pitch roofs. It is also lightweight and provides a durable, weather-resistant surface when installed correctly.
What Are the Disadvantages of Roll Roofing?
While roll roofing is practical for certain applications, it has some limitations. It is not as long-lasting as other roofing materials such as TPO or EPDM, which can last 20 to 30 years. Roll roofing is also not recommended for steep-pitch roofs or high-traffic areas.
Maintenance and Longevity
To maximize the lifespan of a roll roofing installation, regular maintenance is essential. Inspect the roof periodically for signs of wear, damage, or loosening of the material. Reapply roofing cement to any gaps or seams as needed.
Avoid walking on the roof unnecessarily, as this can cause damage to the roofing material. If repairs are needed, address them promptly to prevent further deterioration.
Conclusion
Asphalt roll roofing is a practical and cost-effective solution for low-pitch roofs. With the right tools, materials, and preparation, most DIYers can successfully install roll roofing without professional assistance. However, it is important to follow proper installation guidelines to ensure a durable and long-lasting result.
By carefully preparing the roof surface, applying roofing cement correctly, and securing the material with nails, you can achieve a secure and weather-resistant installation. Regular maintenance and inspections will help extend the lifespan of the roll roofing and ensure continued performance.
Roll roofing is not suitable for all roof types, and it is important to consider the limitations and requirements before beginning a project. For best results, choose a day with appropriate weather conditions and follow all safety guidelines during installation.