What to Put Under Metal Roofing: Essential Tips: 1 Minute to Choosing the Right Underlayment for Metal RoofingSarah ThompsonJan 19, 2026Table of ContentsTips 1FAQFree Smart Home PlannerAI-Powered smart home design software 2025Home Design for FreeWhen installing metal roofing, choosing the right underlayment is crucial to protect your home from moisture, temperature changes, and noise. The underlayment acts as a barrier between the metal panels and your roof deck, ensuring durability and weather protection for years. The most common materials used under metal roofing are felt, synthetic underlayments, and self-adhering membranes. Felt underlayment is traditional, offering basic protection and cost-effectiveness. Synthetic options are lightweight, durable, and provide superior moisture resistance. Self-adhering membranes, while pricier, ensure a watertight seal, making them ideal for areas prone to heavy rain or snow. As a designer, I always consider the functional layer beneath aesthetic finishes; in roofing, this hidden layer is as vital as what you see. For projects requiring precision and efficiency, leveraging a floor planner can help visualize how roof layers integrate with other architectural details, ensuring your metal roofing choice supports both form and function.Tips 1:Always check local building codes before selecting your underlayment, as requirements can vary by region and climate.FAQQ: What is the best underlayment for metal roofing?A: Synthetic underlayment is generally considered best for its durability, water resistance, and longevity.Q: Can you put metal roofing directly on plywood?A: While possible, using an underlayment is strongly recommended to protect against moisture and increase roof lifespan.Q: Is felt underlayment good enough for metal roofs?A: Felt can be used, but synthetic options typically offer better protection and performance.Q: Does the type of underlayment impact energy efficiency?A: Yes, some underlayments can reflect heat, improving your home’s energy efficiency.Q: Should you install a vapor barrier under metal roofing?A: In humid or cold climates, a vapor barrier can prevent condensation and protect the roof structure.Home Design for FreePlease check with customer service before testing new feature.