Roof Flashing and Seam Repair: Essential Techniques for Commercial Roofing Contractors
As a growing commercial roofing contractor, mastering the skills of roof flashing and seam repair is essential to delivering long-lasting results that protect your clients’ properties. Roof flashing and seams are critical elements that, if not properly maintained or repaired, can lead to leaks, water damage, and costly repairs. In this post, we'll delve into the essential techniques for repairing or replacing roof flashing and repairing seams to ensure your projects stand the test of time.
Understanding the Importance of Roof Flashing and Seams
Roof flashing and seams are vulnerable areas where leaks are most likely. Flashing is typically installed around roof penetrations such as, RTU’s, vents, skylights, and edges where the roof meets a vertical surface like a wall. Seams, especially in flat or low-slope roofs, are where two pieces of roofing material meet and are bonded together. Proper installation and maintenance of both components are critical to preventing leaks.
Roof Flashing Repair Techniques
1. Identifying Flashing Issues Roof flashing is usually made from metal (often galvanized steel or aluminum) and is prone to corrosion, bending, or detaching over time. Common issues include rust, missing flashing, or improper installation, which can lead to water penetration. The first step in flashing repair is identifying these problems before escalating.
2. Remove Damaged Flashing When you find damaged or corroded flashing, it’s best to replace it rather than patch it up. Remove the existing flashing carefully without causing damage to surrounding materials. If the flashing is under shingles or membranes, lift the roofing material enough to work underneath it without tearing or ripping it.
3. Install New Flashing When installing new flashing, ensure it is appropriately shaped to channel water away from vulnerable areas. Overlap the edges of the flashing pieces to prevent water from seeping through. Make sure the new flashing is securely fastened and sealed. Use roofing nails or screws, but be cautious not to over-tighten and deform the material. Finish by applying a high-quality roofing sealant or caulking around the flashing edges.
4. Sealing Flashing Joints After installing the new flashing, it's critical to seal all the joints with a waterproof roofing sealant. Check all areas around the vent pipes, or skylights to ensure no gaps or loose seams where water can enter.
5. Routine Maintenance: Even with proper installation, flashing requires periodic maintenance to remain functional. Make checking flashing integrity part of your routine inspections, as early detection of potential problems can prevent costly repairs in the future.
How to Repair Roof Seams
1. Inspection of Roof Seams Seams, particularly on flat or low-slope roofs, can separate or lose adhesion over time due to weathering, thermal expansion, or improper installation. Common issues with seams include water infiltration, bubbling, and cracking. Regularly inspect seams for signs of stress, splitting, or loss of adhesion.
2. Cleaning the Area Before repairing roof seams, clean the area thoroughly. Dirt, debris, and moisture can compromise the adhesion of the repair material. Use a stiff brush to remove debris and clean the surface with a cleaner compatible with your roofing material, ensuring the area is dry before proceeding.
3. Apply Seam Tape: Seam tape is one of the most effective methods for minor seam repairs. Choose a tape that matches the type of roofing membrane—EPDM, TPO, or PVC. Cut the tape to the desired length and apply it directly over the seam. Roll the tape with a seam roller to ensure it adheres appropriately and eliminates air bubbles.
4. Hot-air Welding (for TPO and PVC Roofing): If you're dealing with thermoplastic roofs (such as TPO or PVC), hot-air welding is the preferred method for seam repair. Use a hot-air welder to bond the roofing membrane at the seams. This method creates a robust, waterproof seam that can withstand extreme weather conditions. Ensure you follow the manufacturer's guidelines for temperature settings and techniques to avoid damaging the material.
5. Liquid-Applied Sealant Another option for seam repair is using liquid-applied sealant. This method is effective for more extensive seam failures or areas where seam tape may not be practical. Apply the sealant evenly over the seam using a brush or roller, ensuring full coverage and allowing it to cure properly for a watertight seal.
6. Reinforcing Weak Seams For seams that are prone to recurrent issues, additional layers of seam tape or flashing tape can provide extra protection. This is especially important in high-stress areas such as roof edges or around penetrations where seams are more likely to fail.
Prevention: Best Practices for Flashing and Seam Longevity
As with most aspects of roofing, prevention is the best approach. A few best practices include:
Quality materials: Use high-grade flashing, seam tape, and sealants to withstand UV rays, thermal expansion, and moisture.
Proper installation: Follow manufacturer guidelines for both flashing and seam installation. Cutting corners can lead to costly repairs and damage.
Scheduled maintenance: Regularly inspecting and maintaining flashing and seams ensures minor issues are detected and resolved before they become major problems.
Final Thoughts
Mastering roof flashing repair techniques and understanding how to repair roof seams effectively will increase the longevity of the roofs you work on and strengthen your reputation as a dependable commercial roofing contractor. Your clients depend on your expertise to protect their buildings from water damage, and knowing how to address these critical roofing elements will ensure their satisfaction and your continued success.
By implementing these best practices and repair techniques, you’ll provide quality service, minimize the risk of leaks, and extend the life of the roofs you manage—helping your business grow through reliability and excellence.
By avoiding potential problems with proactive repairs, you'll save your clients time, money, and frustration while building trust and securing future projects.
