Installing a moisture barrier under a metal roof is advisable as it prevents moisture intrusion, manages condensation, protects insulation, and enhances energy efficiency. This step safeguards the roof deck from damage and extends the roof’s lifespan. นอกจากนี้, it complies with many local building codes, ensuring the structure meets required standards for moisture protection. The correct installation of a moisture barrier is crucial and should be done in accordance with professional guidance and regulations.