A raggle is essentially a specialized groove or channel designed to secure flashing, particularly in masonry construction. It plays a crucial role in preventing water penetration in buildings, especially around roof edges and wall intersections.
Understanding Raggles
A raggle serves two primary purposes, often depending on the context of its application:
- A Groove in Masonry: Most commonly, a raggle refers to a groove or cut made directly into a masonry surface, such as a brick wall or chimney. The main function of this groove is to receive and hold the upper edge of a flashing material. This is particularly vital where a roof meets a vertical wall, ensuring a watertight seal. The flashing is inserted into this groove, then often sealed with a sealant to create a durable, weather-resistant barrier.
- A Manufactured Building Unit: In some cases, a raggle can also refer to a prefabricated building unit that comes with a pre-cut groove specifically designed to accommodate metal flashing. These units are integrated into the structure during construction, simplifying the process of installing flashing and ensuring a consistent, precise fit.
Importance and Application
Raggles are fundamental to effective waterproofing in construction. They are primarily used in scenarios where:
- Roof-to-Wall Transitions: This is one of the most common applications. Where a roof plane abuts a vertical masonry wall (like a chimney, parapet wall, or an adjacent building wall), a raggle is cut into the masonry. This allows counter-flashing to be inserted, directing water away from the wall and down onto the roof or into gutters.
- Expansion Joints: In some cases, raggles can be part of systems designed to manage expansion and contraction in large masonry facades, ensuring that water is still effectively managed.
- Architectural Features: For specific architectural details requiring water diversion, raggles can be custom-cut to integrate flashing seamlessly.
Key Benefits of Using Raggles:
- Enhanced Water Sealing: By providing a secure recess for flashing, raggles significantly improve the effectiveness of water barriers, preventing leaks and moisture damage.
- Durability: Flashing secured within a raggle is less exposed to environmental elements like wind, sun, and physical impact, leading to a longer lifespan for the seal.
- Aesthetics: Properly installed flashing within a raggle results in a cleaner, more professional finish, as the flashing is neatly tucked away.
- Structural Integrity: Preventing water ingress helps maintain the integrity of the building materials and structure over time.
Raggles can be cut using specialized tools, often diamond blades, to create a precise and clean groove. The flashing, typically made of durable materials like copper, lead, or aluminum, is then inserted into this groove and sealed to provide a robust, long-lasting weather seal.
