軽いオーク ポリ塩化ビニールの内部ドア-MD-3009A

Solid wood doors use natural timber (oak, ash, walnut) and give the richest grain, but they move most with humidity. Engineered doors bond a stable core (LVL, finger-joint or solid-core board) with veneer or laminate, so they resist warping far better. WPC (wood-plastic composite) is fully waterproof, termite-proof and needs almost no maintenance, which is why it now dominates bathrooms, kitchens and tropical projects.

Any timber absorbs moisture, so a door can cup, swell or bind when indoor relative humidity swings. The risk is controlled three ways: kiln-drying to 8–12% moisture content, balanced construction (equal veneer or laminate on both faces, engineered core), and complete six-sided sealing. For coastal and tropical projects we recommend engineered or WPC cores, or solid wood with full edge sealing and a stable 40–60% indoor RH.

A solid core door replaces the hollow honeycomb cavity with a dense engineered core, so it weighs far more, blocks noticeably more sound, resists dents and closes with a substantial feel. For bedrooms, bathrooms and home offices the upgrade usually pays back in comfort and resale appeal. For closets, pantries and low-traffic storage, a hollow core remains a sensible saving.

Choose solid core. A hollow core door is light and cheap but transmits conversation almost unchanged, while a solid core door typically adds meaningful sound reduction and privacy. If the room is a nursery, home office or shares a wall with a living area, solid core plus a perimeter seal and a drop-down door bottom is the standard recommendation.