The Solar Dowel Screw Hanger Bolt for Wood with EPDM Washer is a specialized fastening solution designed to securely mount solar panel racking systems to wooden roof structures while ensuring a watertight seal. This type of hanger bolt combines the robust anchoring capability of a dowel screw (also known as a hanger bolt) with the critical advantage of an integrated or compatible EPDM rubber washer for superior weatherproofing. It’s an essential component for durable and leak-free solar installations on roofs with wood rafters or purlins.

Definition

A Solar Dowel Screw Hanger Bolt for Wood with EPDM Washer is a dual-threaded fastener engineered for photovoltaic (PV) mounting applications. It features a lag screw thread at one end for secure, deep penetration and anchoring into wooden roof members (such as rafters or purlins). The opposing end has a machine screw thread for attaching solar racking components (e.g., L-feet, mounting plates). Crucially, it is supplied with or features an integrated EPDM (Ethylene Propylene Diene Monomer) washer that compresses against the roof surface upon installation, creating a durable, flexible, and completely watertight seal around the roof penetration point.

Key Features

• Dowel Screw Design: Features a robust lag screw thread for strong purchase in wood and a machine screw thread for external attachments.
• EPDM Washer: Includes a high-quality EPDM rubber washer, which provides an effective and long-lasting waterproof barrier against water ingress at the point where the bolt penetrates the roof.
• Material: Typically made from high-grade stainless steel (e.g., A2/AISI 304 or A4/AISI 316) for excellent corrosion resistance and durability in outdoor environments.
• Adjustable Height (Optional): Some designs may offer a degree of adjustability to allow for leveling of the solar rails and compensation for roof irregularities.
• Drive Type: Often features a hex drive or Torx drive on the lag screw end for easy and secure installation into wood.
• Roof Compatibility: Designed for direct installation into wooden roof structures, suitable for various roof coverings when used with appropriate flashing or adapters (e.g., tile roofs, slate roofs).

Advantages

• Watertight Seal: The primary advantage is the EPDM washer, which ensures a highly reliable and durable waterproof seal, preventing leaks and protecting the roof structure from moisture damage.
• Strong Wood Anchor: The dowel screw’s lag thread provides exceptional pull-out resistance and a secure, long-lasting connection to wooden rafters or purlins.
• Corrosion Resistance: Stainless steel construction offers excellent resistance to rust, weathering, and harsh environmental conditions, ensuring the longevity of the entire PV system.
• Simplified Installation: Combining the fastener and seal into one component or system streamlines the installation process.
• Versatility: Suitable for a wide range of pitched wooden roof types and can be adapted for various roofing materials using compatible flashing systems.
• Durability: Engineered for outdoor use, these hanger bolts contribute to the overall stability and longevity of the solar panel installation.

Applications

• Residential Solar Panel Installations: Ideal for securing solar PV systems on residential homes with wooden roof structures, ensuring a safe and leak-free installation.
• Commercial and Industrial Roofs: Used in commercial solar projects on buildings with wooden roof framing where a secure and waterproof connection is essential.
• Pitched Roofs: Specifically designed for pitched roofs where direct anchoring into wood is feasible.
• Tile, Slate, and Shingle Roofs: Commonly employed in conjunction with specialized roof hooks, flashing kits, or mounting plates to integrate seamlessly with these roofing materials while anchoring into the underlying wood rafters.
• Structural Integrity: Essential for maintaining the structural integrity of the roof by preventing water ingress at penetration points.