DIY Guide: Mastering Rolled Roofing Installation – Step-by-Step Instructions

Rolled roofing, also known as modified bitumen roofing, is a popular choice for flat or low-sloped roofs on garages, sheds, carports, and other outbuildings. It’s a cost-effective and relatively easy-to-install material, making it a great DIY project for homeowners willing to put in the effort. However, proper installation is crucial to ensure its longevity and effectiveness in protecting your structure from the elements. This comprehensive guide will walk you through the entire process, providing detailed steps and instructions to help you successfully install rolled roofing.

Understanding Rolled Roofing

Before diving into the installation process, it’s essential to understand what rolled roofing is and its specific characteristics. Rolled roofing comes in long rolls, typically 36 inches wide, and is composed of layers of asphalt or modified bitumen reinforced with fiberglass or polyester. It’s designed to create a waterproof barrier on low-sloped roofs where traditional shingles are not suitable. There are two main types of rolled roofing: self-adhering and torch-down. This guide primarily focuses on the self-adhering variety, which is more DIY-friendly, but we will also mention torch-down for those interested.

Types of Rolled Roofing:

• Self-Adhering Rolled Roofing: This type has a peel-and-stick backing, making installation simpler and safer, as it doesn’t require open flames. It’s ideal for most DIY projects.
• Torch-Down Rolled Roofing: This type requires a torch to heat the adhesive, creating a strong bond. It is often used by professionals due to the skill and safety precautions required.

Tools and Materials You’ll Need

Before you start, gather all the necessary tools and materials to ensure a smooth installation. Here’s a comprehensive list:

• Rolled Roofing Material: Calculate the square footage of your roof, adding a 10% waste factor, to determine how much you’ll need. Purchase both the base sheet and cap sheet if using a two-layer system
• Utility Knife or Roofing Knife: For cutting the rolled roofing material.
• Metal Shears: For cutting metal drip edge.
• Measuring Tape: For accurate measurements.
• Chalk Line: For marking straight lines.
• Roofing Nails or Staples: Check manufacturer instructions, some rolled roofing requires mechanical fasteners.
• Hammer or Staple Gun: For securing mechanical fasteners.
• Roofing Cement or Seam Sealer: For sealing seams and edges.
• Push Broom or Stiff Bristle Brush: For cleaning the roof surface.
• Safety Glasses: To protect your eyes.
• Work Gloves: To protect your hands.
• Ladder: A sturdy ladder to access your roof safely.
• Drip Edge: Metal flashing to protect the roof edges.
• Tape Roller: Specifically designed for roofing to press seams firmly
• Optional: Torch (for torch-down roofing): If you’re working with torch-down roofing, you’ll need a propane torch. Only to be used by experience professionals and following all safety standards

Preparation is Key

Proper preparation is essential for a successful rolled roofing installation. Follow these steps before laying the material:

1. Inspect the Roof Deck: Check the roof sheathing for any damage, rot, or loose boards. Replace any damaged sections to ensure a solid base for the roofing. Make sure to secure any nails that may be sticking up.
2. Clean the Roof Surface: Use a broom or a stiff-bristle brush to remove all debris, dirt, leaves, and loose gravel. A clean surface will ensure proper adhesion of the rolled roofing.
3. Install Drip Edge: Attach metal drip edge along the eaves and edges of the roof using roofing nails or screws. Ensure the drip edge extends over the fascia board to direct water away from the structure. The drip edge should have overlap sections of at least an inch.
4. Measure and Cut: Measure the length of your roof and cut the rolled roofing material to the required length. Add an extra few inches to allow for overlap. For a base layer add 4 to 6 inches for the horizontal overlap. The vertical overlap should be about 2 to 4 inches. For a cap sheet the horizontal overlap can be reduced to 2 or 4 inches. The vertical overlap should remain the same at 2 to 4 inches. Be careful with the utility knife and measure and re-measure to avoid errors.
5. Plan Your Layout: Determine the direction you’ll lay the rolled roofing, typically starting from the lowest point of the roof and working upwards. Use a chalk line to mark a starting line. This ensures proper water runoff with the overlap going down instead of up.

Step-by-Step Installation Guide (Self-Adhering)

Now, let’s get into the step-by-step process of installing self-adhering rolled roofing:

1. Position the First Roll: Starting at the lowest edge of the roof, position the first roll of roofing material along your marked chalk line. It’s best to start by unrolling a few feet at a time and peeling off the backing as you go. Ensure it overhangs the drip edge slightly.

2. Align and Secure: Align the edge of the rolled roofing with the chalk line and press it firmly onto the roof deck. Peel away the backing gradually as you lay down the material, ensuring there are no air bubbles and that the material is laying flat. Use the tape roller to firmly press the material to the roof sheathing.

3. Continue Laying the First Course: Continue unrolling the roofing material, removing the backing, and pressing it down as you move across the roof. Overlap any side edges by at least 2-4 inches horizontally, and then use a tape roller to ensure a tight seal. If the rolled roofing has nails on the edges these should be nailed down every 4-6 inches.

4. Start the Second Course: When starting the second course you should offset the first and second layer. Typically you want to offset at least 12 inches to avoid having multiple layers line up creating a weak point. Measure and cut the second course piece, and continue the same installation process, starting at the lowest point.

5. Overlap Seams: Overlap the end of each roll of roofing by 4 to 6 inches horizontally, and then use a tape roller to firmly press down and seal the edge down. Be sure to check manufacturers specifications. If required, add roofing cement along the seam to further enhance the seal and provide additional protection against water penetration. Vertical overlap should be at least 2-4 inches and also require a tape roller to firmly seal the edge.

6. Install the Second Layer (Cap Sheet) : If installing a two-layer system, you’ll then install the cap sheet, typically with less overlap than the base sheet. This second layer is essential to achieve a high-quality roofing solution. It provides an additional layer of waterproofing and increases the overall durability and longevity of the roof. Make sure the edges are also properly sealed with a tape roller.

7. Seal the Edges: Once all the rolls are in place, apply roofing cement or seam sealer to all the edges and seams of the rolled roofing. Be sure to carefully seal around any protrusions or corners. Use a caulking gun to ensure smooth and consistent coverage. This will further protect the roof from leaks.

8. Inspect your Work: After installation, carefully inspect the entire roof for any loose seams, air bubbles, or improperly sealed areas. Use a tape roller or additional sealant to fix any imperfections. Make sure there is a good seal all around.

Torch-Down Rolled Roofing (Brief Overview)

While self-adhering rolled roofing is more DIY-friendly, torch-down roofing offers excellent long-lasting results. However, it requires careful handling and safety precautions. Here’s a brief overview of the process:

1. Prepare the Surface: Clean the roof surface and install drip edge, same as self-adhering.
2. Position the Roll: Position the first roll of roofing material along the starting line.
3. Heat the Adhesive: Use a propane torch to carefully heat the bottom of the rolled roofing material until the adhesive melts, creating a bond with the roof deck.
4. Press and Roll: Immediately press the heated material down and roll it out using a roofing roller.
5. Overlap Seams: Overlap the seams by at least 2-4 inches and heat again to ensure a strong bond.
6. Seal the Edges: Seal the edges with roofing cement or sealant.

Safety Note: Working with a propane torch can be dangerous if not done correctly. It’s crucial to follow all safety guidelines and wear appropriate protective gear, including fire-resistant clothing, gloves, and safety glasses. If you’re not comfortable working with a torch, it’s best to hire a professional roofer.

Tips for Success

• Choose the Right Weather: Install rolled roofing on a dry, calm day with temperatures above 50 degrees Fahrenheit for self-adhering types. Avoid hot days as the self-adhering backing can become difficult to work with. For torch-down roofing, you can work in cooler temperatures but avoid any wet conditions.
• Take Your Time: Don’t rush the installation process. Taking your time to ensure the rolled roofing is properly aligned, sealed, and secured is essential. Pay attention to the manufacturer’s instructions for application methods.
• Use Quality Materials: Investing in high-quality roofing materials will ensure the longevity and durability of your roof.
• Check for Overlap: Ensure all seams and overlaps meet or exceed the manufacturer’s recommendations. This is critical for proper waterproofing.
• Use a Tape Roller: Press seams down firmly with a tape roller to ensure proper adhesion and waterproofing.
• Consult Professionals: If you are unsure about any aspect of the installation process, consult with a professional roofer for advice or assistance.

Maintenance of Rolled Roofing

Once your rolled roof is installed, regular maintenance will help extend its life and performance:

• Regular Inspections: Conduct regular inspections, especially after heavy storms, to check for any damage, loose seams, or other issues. Early detection and repair of issues can prevent major problems.
• Clean the Surface: Remove debris, leaves, and dirt regularly to prevent water from pooling and causing damage.
• Repair Minor Damage: Repair minor damage immediately. Use roofing cement to seal any cracks or tears you find.
• Avoid Sharp Objects: Be careful not to puncture the roofing membrane with sharp objects when conducting maintenance or other tasks.

Conclusion

Installing rolled roofing is a manageable DIY project with careful planning and execution. By following the steps outlined in this guide, you can confidently install a durable and waterproof roof on your flat or low-sloped structure. Remember to prioritize safety, use quality materials, and take your time to ensure proper installation. With proper care and maintenance, your rolled roofing will provide reliable protection for years to come.