The roofing industry has evolved significantly in recent years, with advancements in materials and installation techniques improving durability, efficiency, and weather resistance. One such innovation is GRP (Glass Reinforced Plastic) dry valleys, which have become a popular choice for roofers looking for a reliable, low-maintenance solution for valley drainage.
In this blog, we’ll explore what GRP dry valleys are, their benefits, and why they are a superior alternative to traditional lead or mortar-based valley systems.
What Are GRP Dry Valleys?
GRP dry valleys are pre-formed valley troughs made from Glass Reinforced Plastic (GRP), a lightweight yet durable composite material. These valleys are installed at the junction between two sloping roof sections, allowing for efficient drainage of rainwater while preventing leaks.
Unlike traditional lead or mortar valleys, which require more intensive installation and upkeep, GRP valleys offer a "dry fix" solution—meaning they don’t require mortar bedding, reducing maintenance issues and installation time.
Benefits of Using GRP Dry Valleys in Roofing
1. Durability and Longevity
GRP is highly resistant to extreme weather conditions, UV rays, and temperature fluctuations. Unlike lead, which can corrode over time, or mortar, which can crack and deteriorate, GRP remains structurally sound for decades.
2. Easy Installation
One of the biggest advantages of GRP dry valleys is their ease of installation. Unlike traditional methods that require specialized skills (such as leadwork or mortar pointing), GRP valleys can be quickly fitted by roofers of all experience levels. Their pre-formed design ensures a consistent fit and reliable water runoff.
3. Cost-Effective
GRP valleys are significantly cheaper than lead alternatives. Additionally, since they do not require mortar, ongoing maintenance costs are reduced. The faster installation time also cuts down on labor costs, making GRP an economical choice for contractors and homeowners alike.
4. Environmentally Friendly
With sustainability becoming an increasing priority in construction, GRP dry valleys offer a greener alternative. Unlike lead, which is a non-renewable and potentially harmful material, GRP is a composite that does not leach toxic substances into the environment.
5. Aesthetically Pleasing
GRP valleys are available in different colors and finishes, allowing roofers to match them with various roof tile styles. Their sleek design also provides a cleaner finish compared to traditional mortar valleys.
Installation Guide: How to Fit a GRP Dry Valley
Step 1: Preparation
- Ensure the valley area is clean and free of debris.
- Lay roofing underlay beneath the valley area to prevent water ingress.
Step 2: Positioning the GRP Valley
- Align the GRP valley trough centrally along the valley line.
- Fix it in place using roofing nails or clips, ensuring a secure fit.
Step 3: Tile Installation
- Lay the roof tiles on either side of the valley, maintaining a small gap to allow for expansion.
- Avoid overhanging tiles too far over the GRP valley to prevent water from flowing sideways.
Step 4: Securing and Finishing
- Check that all tiles and valley edges are properly secured.
- Perform a water test to ensure proper drainage before finalizing the installation.
Why GRP Dry Valleys Are the Future of Roofing
With increasing regulations on lead use and the demand for low-maintenance solutions, GRP dry valleys are becoming the preferred choice for modern roofing projects. Their lightweight, durable, and cost-effective nature makes them a smart investment for both roofing professionals and homeowners.
If you’re in the roofing industry and haven’t yet made the switch to GRP dry valleys, now is the time to consider integrating them into your projects!
Conclusion
GRP dry valleys provide a high-performance, long-lasting, and easy-to-install alternative to traditional roofing valleys. Whether you're a contractor, builder, or homeowner, making the switch to GRP valleys can enhance the durability, efficiency, and aesthetics of any roofing project.
Are you already using GRP dry valleys in your work? Let us know your experiences and tips in the comments below!