Before installing a metal roof, several layers of materials are typically applied to ensure proper insulation, moisture protection, and a smooth surface for the metal panels. The layers commonly used in the installation of a metal roof are as follows:
Roof Decking: The roof decking is the foundation of the roof and provides the structural support for the entire roofing system. Common materials for roof decking include plywood or oriented strand board (OSB).
Underlayment: The underlayment is a moisture barrier that is placed over the roof decking to protect the roof from water infiltration. There are two main types of underlayment used for metal roofs:
a. Synthetic Underlayment: Made from synthetic materials, such as polyethylene or polypropylene, synthetic underlayment offers superior tear resistance and durability. It is lightweight and easy to handle.
b. Felt Underlayment (Asphalt-saturated felt): Asphalt-saturated felt, also known as roofing felt or tar paper, is a traditional option that provides good waterproofing properties. However, it is generally heavier and can be more susceptible to tearing during installation compared to synthetic underlayment.
Ice and Water Shield (Optional): In regions with cold climates or where ice dams are a concern, an ice and water shield may be added on top of the underlayment. This self-adhesive membrane helps prevent water from infiltrating the roof due to ice buildup.
Metal Roofing Panels: Once the underlayment and optional ice and water shield are in place, the metal roofing panels are installed on top. The type of metal roofing panels used can vary, including steel, aluminum, or copper, depending on the design and requirements of the project.
It's important to follow the manufacturer's guidelines and local building codes when installing a metal roof. Proper installation and the use of appropriate materials will ensure the longevity, performance, and protection of the metal roofing system. Additionally, professional installation is recommended to achieve the best results and avoid potential issues with the roof in the future.