In Utah’s low-humidity climate, material choice matters. MDF is dimensionally stable in conditioned interior spaces and provides the smoothest paint surface — the default for most Utah residential trim in climate-controlled rooms. Solid poplar is preferred for custom millwork where strength, workability, and paint quality are all needed. PVC cellular trim is 100% moisture-resistant and dimensionally stable regardless of humidity — the right choice for bathrooms, mudrooms, and anywhere moisture is a concern. RainFire Builders specifies material by location rather than applying one material across the entire home.