A plain interior door is the most common upgrade opportunity in any home. The door is functional, but it's also a major visual element in the room — the eye reads the door as a flat surface, and the room reads as a builder-grade interior. A door trim upgrade changes the door from flat to designed.
The simplest door trim upgrade is the addition of a casing. A PU casing, 80 to 150 millimeters wide, applied to the door frame around the opening. The casing frames the door, adds visual weight, and the room reads as more finished.
A more developed door trim upgrade is the addition of a surround. A complete PU surround kit — head casing, side casings, corner blocks, and a small cornice above the head. The surround is a substantial architectural element, and the door reads as a designed feature.
A more developed door trim upgrade is the addition of panels. A flat flush door is upgraded with PU panel moldings applied to the door's surface. The moldings form a panel layout (a single large panel, a two-panel layout, a six-panel layout), and the door reads as a traditional paneled door. The upgrade is reversible, and the original door is preserved.
A more developed door trim upgrade is the addition of a pediment. A PU pediment applied above the door, with a classical triangular or broken pediment shape. The pediment adds a substantial classical element to the door, and the room reads as more formal.
A more developed door trim upgrade is the addition of a full surround with pilasters. PU pilasters applied to each side of the door, with a substantial head casing and a pediment above. The surround is a major architectural element, and the door reads as a grand entrance.
For sourcing, the right conversation with the factory is about the door size, the design style, and the level of upgrade. The factory can supply any of the above options, from a simple casing to a full surround with pilasters. The lead time varies from short (stock casings) to longer (custom surrounds).
A practical install note: the upgrade should be planned around the door's existing condition. A door that is already in good condition (no damage, no warp) is a good candidate for any of the above upgrades. A door that is damaged or warped should be replaced before the upgrade is applied.
A practical note on the reversibility. The panel molding upgrade (applying moldings to the door's surface) is reversible — the moldings can be removed and the door returned to its original condition. The surround upgrade (casing, pediment, pilasters) is also reversible, because the PU pieces are applied to the wall and the door frame, not to the door itself.
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Frequently Asked Questions
Q: What is polyurethane (PU) decorative material?
A: Polyurethane (PU) decorative material is a high-density closed-cell polymer molded into architectural profiles such as cornices, ceiling medallions, wall panels, columns, and skirting boards. It replicates the appearance of plaster, carved wood, or stone at one-quarter the weight, is fully waterproof, impact-resistant, and arrives factory-primed for paint.
Q: How does PU compare with plaster and wood mouldings?
A: PU is lighter than plaster (no scaffolding required), impact-resistant during transport, and immune to cracking. Compared with wood, PU does not warp, split, or attract termites, and it tolerates moisture in bathrooms and kitchens. The trade-off: PU cannot be refinished the way solid wood can, but its lifespan is 20–30+ years with minimal maintenance.
Q: How do you cut and finish PU mouldings?
A: Cut PU mouldings with a fine-tooth miter saw (40+ teeth for a 10-inch blade) to avoid chipping the molded edge. Sand the cut edge with 220-grit, then apply two coats of interior latex paint. Mitre joints at corners, fill seams with lightweight spackle, sand smooth, and finish with one final top coat.
Q: Is PU moulding safe for indoor air quality?
A: Yes. Premium PU mouldings are manufactured without formaldehyde, asbestos, or VOCs. They meet EN 13501-1 Class E fire classification as a minimum, with Class B fire-retardant versions available for commercial projects. The factory-applied water-based primer further reduces off-gassing once installed.