Rolled roofing installation is a popular and cost-effective method for covering low-slope or flat roofs on structures like sheds, garages, and some residential additions. This type of roofing material, typically composed of asphalt-saturated felt or fiberglass mat coated with mineral granules, comes in large rolls that are easier and faster to install than individual shingles. For DIY enthusiasts and professionals alike, understanding the proper techniques for rolled roofing installation is crucial for ensuring a durable, weather-resistant, and long-lasting roof.
Before beginning any rolled roofing installation project, thorough preparation is essential. Start by inspecting the existing roof deck. It must be clean, dry, and structurally sound. Replace any rotted or damaged wood. The deck should be solid plywood or oriented strand board (OSB). Next, ensure the surface is smooth and free of any nails, debris, or protruding objects that could puncture the roofing material. For a new roof, install a proper underlayment, such as roofing felt, to provide an additional layer of protection against moisture.
Gathering all the necessary tools and materials beforehand will make the process smoother. You will need the rolled roofing material itself, roofing nails (preferably galvanized or aluminum with large heads), a hammer or roofing nailer, a utility knife with sharp blades, a chalk line, a measuring tape, a sturdy ladder, roofing cement, and a brush or trowel for applying the cement. Safety equipment, including non-slip shoes, gloves, and safety glasses, is non-negotiable for any roofing project.
The core steps of the rolled roofing installation process are methodical and require attention to detail. Begin by measuring the roof to determine how many rolls you will need, always accounting for a slight overlap at the edges and ends. It is advisable to let the roll acclimate to the outdoor temperature for a day before installation to make it more pliable and easier to work with.
- Snap a Guide Line: Use your chalk line to snap a straight horizontal line near the bottom edge of the roof. This line is critical for ensuring your first course of roofing is perfectly straight, which will guide all subsequent courses.
- Apply the First Course: Unroll the first sheet along the chalk line, allowing for a slight overhang (about 1/4 to 1/2 inch) beyond the eaves and rakes. This overhang will be trimmed later. Secure the material by nailing it along the top edge, placing nails about every 12 inches and 1 inch from the edge. Do not nail along the bottom yet.
- Overlap and Secure Subsequent Courses: Unroll the next course, overlapping the first course by at least 2 inches. This overlap is vital for preventing water infiltration. Secure this course by nailing along the top edge, just as you did with the first. Continue this process up the roof until you reach the ridge.
- Dealing with the Ridge: For the final course at the ridge, you have two common options. You can run the material over the ridge and down the other side by a few inches, securing it with nails and covering the nail heads with roofing cement. Alternatively, you can install a separate ridge cap piece cut from the rolled material, sealing it thoroughly with roofing cement.
- Seal the Seams and Edges: This is a critical step for waterproofing. Lift the overlapping edge of each course and apply a generous bead of roofing cement underneath along the entire length. Press the material back down firmly. Also, seal all nail heads with a dab of cement and apply cement along all roof edges and overlaps.
- Final Trimming: Once all courses are installed and sealed, use your utility knife to carefully trim any excess overhang along the eaves and rakes for a clean, finished appearance.
While rolled roofing installation is manageable for a seasoned DIYer, several common pitfalls must be avoided to ensure success. One major mistake is installing the material on a roof with too steep a pitch. Rolled roofing is designed for low-slope roofs; using it on a steep pitch can lead to failure. Another error is insufficient nailing or using the wrong type of nails, which can cause the material to lift in high winds. Perhaps the most common error is inadequate sealing of seams and nail heads. This compromises the entire roof’s waterproofing integrity, leading to leaks and premature deterioration. Always use a high-quality roofing cement and apply it liberally.
The advantages of choosing a rolled roofing installation are significant. It is one of the most economical roofing options available, making it ideal for budget-conscious projects and secondary structures. The installation process is relatively quick and straightforward compared to other roofing systems, potentially saving on labor costs. Modern rolled roofing products offer decent durability and can provide reliable protection for 10 to 15 years or more with proper installation and maintenance. It is also readily available at most home improvement stores.
To maximize the lifespan of your new roof, perform regular maintenance. Inspect it at least twice a year, in the spring and fall, and after any major storms. Look for cracks, blisters, or areas where the mineral granules have worn away. Keep the roof clear of debris, such as leaves and branches, which can trap moisture and accelerate wear. Promptly repair any minor damage you find by cleaning the area, applying roofing cement, and patching it with a piece of matching material.
In conclusion, rolled roofing installation is a practical and efficient solution for protecting low-slope structures. By meticulously following the steps of preparation, precise installation, and thorough sealing, you can achieve a professional-looking result that will safeguard your building for years to come. Whether you are a homeowner tackling a garage project or a contractor looking for a reliable material, understanding the nuances of this process is key to its success.