Installing new shingles over your existing roof, a process known as roofing over, can seem daunting, but with careful planning and execution, it's a viable and often cost-effective option. This guide will walk you through the steps, highlighting crucial considerations for a successful project. Remember, always prioritize safety and consider consulting a professional roofer if you're unsure about any aspect of the process.
Assessing Your Existing Roof: The Foundation for Success
Before you even think about nailing on new shingles, a thorough assessment of your current roof is critical. This step will determine the feasibility of roofing over and prevent potential future problems.
1. Roof Condition Inspection:
- Check for damage: Look for missing, cracked, or curled shingles, signs of rot, and any structural issues like sagging or significant water damage. Extensive damage may make roofing over impossible; you might need a complete tear-off instead.
- Evaluate the roof decking: Inspect the plywood or OSB sheathing for rot, soft spots, or significant damage. Repair or replace damaged areas before installing new shingles.
- Assess the underlayment: The underlayment acts as a secondary water barrier. If it's severely damaged or deteriorated, you'll need to replace it before installing the new shingles.
- Consider the existing shingle type: Certain shingle types are better suited for layering than others. Asphalt shingles are commonly used in roofing over projects.
2. Determining Suitability for Roofing Over:
- Roof slope: A steeper roof slope generally makes roofing over easier. Very flat roofs might not be suitable.
- Weight limitations: Adding another layer of shingles increases the roof's weight. Ensure your existing roof structure can handle the added load. Consult a structural engineer if you have any doubts.
- Local building codes: Check your local building codes and regulations for restrictions or requirements regarding roofing over.
Gathering the Necessary Materials and Tools: Preparation is Key
Having the right materials and tools readily available will streamline the installation process and ensure efficiency.
1. Essential Materials:
- New asphalt shingles: Choose shingles that are compatible with your existing roof and meet local building codes.
- Underlayment: If necessary, select a durable underlayment suitable for use under asphalt shingles.
- Starter shingles: These provide a clean, straight starting line for your shingle installation.
- Hip and ridge shingles: These are specialized shingles designed for the roof's edges.
- Nails: Use galvanized roofing nails appropriate for your shingle type.
- Roofing cement: Use this to seal any gaps or cracks.
2. Necessary Tools:
- Hammer: A sturdy claw hammer is essential for nailing shingles.
- Measuring tape: Accurate measurements are crucial for proper shingle layout.
- Utility knife: Used for cutting shingles to fit.
- Ladder: A sturdy ladder that extends safely beyond the roofline is non-negotiable.
- Safety harness and rope: Prioritize safety by using a safety harness and rope to prevent falls.
- Shovel and tarps: For debris removal and protection.
Step-by-Step Shingle Installation: A Detailed Walkthrough
Once your roof is assessed and you have the necessary materials and tools, you can begin the installation.
1. Preparing the Existing Roof:
- Clean the roof: Remove any loose debris, damaged shingles, and moss.
- Repair any damage: Fix any damaged areas of the decking or underlayment before proceeding.
2. Installing the Underlayment (if necessary):
- Unroll the underlayment: Overlap the layers according to the manufacturer's instructions.
- Secure the underlayment: Use roofing staples or nails to fasten it to the roof decking.
3. Installing Starter Shingles:
- Lay the starter shingles: These create a straight, even base for the rest of the shingles.
- Secure them with nails: Follow the manufacturer's instructions for proper nailing.
4. Installing the Main Shingles:
- Begin at the bottom: Work your way up the roof, overlapping each row of shingles.
- Align the shingles carefully: Maintain even spacing and alignment.
- Nail the shingles securely: Use the recommended number of nails per shingle.
5. Installing Hip and Ridge Shingles:
- Install hip and ridge shingles: These cover the edges and peaks of the roof.
- Seal all seams: Use roofing cement to create a watertight seal.
Post-Installation Inspection and Maintenance: Ensuring Longevity
After the installation is complete, a thorough inspection is essential. Check for any loose shingles, gaps, or areas requiring additional sealing. Regular maintenance will extend the life of your new roof.
By carefully following these steps and prioritizing safety, you can successfully install shingles over your existing roof. Remember, however, that roofing is a physically demanding task and involves working at heights. If you're unsure about any part of the process, it's always best to consult a qualified roofing professional. They can assess your specific situation and ensure the job is completed safely and correctly.
