NASCLA Accredited Commercial General ContractorFinishesMedium
A millwork contractor is installing custom wood paneling in a high-humidity commercial restroom. To prevent warping, swelling, and delamination, which type of wood product is generally most suitable for the paneling substrate?
- AExterior-grade Plywood
- BSolid hardwood lumber
- CMedium Density Fiberboard (MDF)
- DParticleboard
Show answer & explanationAnswer & explanation
Correct answer: A. Exterior-grade Plywood
Exterior-grade plywood uses waterproof adhesives and is designed to resist moisture, making it much more stable and durable in high-humidity environments compared to solid wood, MDF, or particleboard, which are prone to swelling and delamination.
Why the other options are wrong
- B. Solid hardwood is susceptible to warping and swelling in high humidity.
- C. MDF absorbs moisture readily and will swell and lose integrity in high-humidity areas.
- D. Particleboard has very poor moisture resistance and will swell and disintegrate rapidly.
Exterior-Grade Plywood
Plywood manufactured with waterproof or moisture-resistant adhesives, designed for use in applications exposed to weather or high humidity.
- Uses Type I (fully waterproof) or Type II (water-resistant) glues.
- More dimensionally stable than solid wood in varying humidity.
- Suitable for exterior use or high-moisture interior environments like bathrooms.
Memory trick: For humid spots, choose EXTERIOR PLYWOOD, as it's built to resist the wet.