Spiral shank umbrella roofing nails are primarily used for attaching roofing materials to the roof deck or sheathing. They are commonly used with asphalt shingles, fiberglass shingles, wood shakes, or other types of roofing materials.The spiral shank design of these nails provides enhanced holding power, ensuring that the roofing material remains securely fastened to the roof deck even during high winds or other harsh weather conditions. The spiral grooves or threads along the length of the nail grip tightly into the wood or other roofing materials, reducing the risk of the nails backing out or becoming loose over time.The umbrella head of these nails serves several purposes. Firstly, it provides a larger bearing surface that helps prevent the nail from pulling through the roofing material. Secondly, the wide head creates a watertight seal by overlapping and covering the shingle or other roofing material above it, preventing water from seeping into the nail hole and causing leaks.Overall, spiral shank umbrella roofing nails are designed to provide a secure and long-lasting attachment for roofing materials, ensuring the integrity and durability of the roof system.