Finishing Lumber

    Filter

      Add the perfect finishing touch to any room with our extensive selection of quality mouldings. Whether you're upgrading baseboards, enhancing cabinet details, or framing windows and doors, we carry a wide variety of styles to suit any design—from classic to contemporary. Choose from finely crafted options in oak, fir, hemlock, maple, MDF, and more. Our moulding collection includes crown mouldings, panel mouldings, corner trim, casings, and baseboards—ideal for DIYers, builders, and designers alike. If you're looking for high-end finishing trim and wainscoting, our S4S lumber selections include the most popular wood species such as oak, walnut, maple, and more. Every piece is sourced with care for quality, consistency, and long-lasting appeal. As a proudly Canadian company with locally owned stores, we focus on personalized service to help bring your vision to life. Whether you're completing a new build or refreshing a space, Windsor Plywood has the right moulding for every project. Visit your local store for expert guidance, custom options, and hard-to-find profiles you won’t see anywhere else.

      6 products

      Frequently Asked Questions

      What is finishing lumber and how does it differ from construction lumber?
      Finishing lumber refers to smooth-planed, appearance-grade wood used for trim, moulding, panelling, shelving, and interior millwork. It is graded for visual quality with minimal knots and defects. Construction lumber is graded for structural strength and is not intended for exposed applications where appearance matters.
      What species are available in finishing lumber at Windsor Plywood?
      Windsor Plywood carries finishing lumber in pine, poplar, hemlock, oak, maple, and MDF-based profiles. Poplar and pine are cost-effective choices for painted applications. Oak and maple are preferred for stained or natural finishes. Hemlock is a strong, stable option that takes paint well and is commonly used for trim in western Canadian construction.
      What does S4S mean in finishing lumber?
      S4S stands for Surfaced Four Sides, meaning the lumber has been planed smooth on all four faces. This is the standard for finishing lumber used in trim and millwork applications. The result is a consistently smooth, flat surface ready for priming, painting, or staining without additional preparation beyond light sanding.
      What grade of finishing lumber should I use for painted trim?
      For painted applications, select a paint-grade or finger-jointed product in pine, poplar, or MDF. These are designed for opaque finishes and are more affordable than clear-grade solid wood. Finger-jointed lumber uses shorter pieces joined end-to-end and is entirely appropriate for painted trim where the joints will not be visible.
      How do I prevent finishing lumber from warping before and after installation?
      Store finishing lumber flat on level supports in the installation space for at least 48 hours before cutting and fitting. This allows the wood to acclimate to the room's temperature and humidity. After installation, prime and paint all four faces including the back, which prevents differential moisture absorption that causes cupping and warping over time.