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Versatile and essential for countless interior finishing projects, our selection of flat stock offers clean lines and endless possibilities. Also known as S4S (surfaced four sides) lumber, flat stock is ideal for creating custom trim, casings, baseboards, window and door accents, shelving, or modern minimalist moulding. We carry a wide selection of sizes, profiles, and species—including MDF, pine, fir, hemlock, and more—so you can find the perfect material to suit your style and project needs. Whether you're building new or updating an existing space, flat stock provides a simple, refined look that works beautifully in both traditional and contemporary designs. As a proudly Canadian company with locally owned stores, Windsor Plywood offers hard-to-source materials, quality craftsmanship, and expert advice. Visit your local store to browse our full selection of flat stock and find exactly what you need to bring your vision to life.
Frequently Asked Questions
What primed wood products does Windsor Plywood carry?
Windsor Plywood carries factory-primed interior trim and moulding products including primed finger-jointed pine, primed MDF profiles, and select primed wood boards. Factory-primed products are ready for finish painting on-site, reducing preparation time. Available profiles include baseboard, casing, crown, chair rail, and flat stock.
What is the advantage of factory-primed trim versus unprimed?
Factory priming applies a consistent, even primer coat under controlled conditions that is difficult to replicate on a job site. The primer is applied before the moulding is cut to length, which means all four faces and edges are sealed. This reduces the amount of site preparation and provides a better base for finish coats. Factory-primed trim also allows immediate painting without waiting for primer to dry on site.
Do I need to apply additional primer over factory-primed trim?
A light coat of site-applied primer or a quality finish primer over the factory prime coat improves adhesion of the topcoat and fills any handling marks or small surface imperfections. Lightly sanding the factory prime coat with 220-grit before applying site primer improves adhesion. Two finish coats over the site primer typically produce a high-quality painted trim result.
Can factory-primed trim be stained instead of painted?
No. Primed products are designed for painted applications. The primer coat seals the wood and prevents stain penetration and proper colour development. Applying stain over primer produces uneven, poor results. For stained applications, select unprimed solid wood or veneer products appropriate for the desired species and finish.
Is factory-primed trim suitable for bathroom and kitchen environments?
Standard factory-primed wood trim is appropriate for bathrooms and kitchens when properly painted with a moisture-resistant finish. The primer and paint system protects the wood from typical household humidity. For areas with direct water contact such as around tubs and showers, use a fully waterproof material such as PVC trim or ensure the installation is fully caulked and the paint system is rated for wet areas.