Square Stock

Shop our S4S (Surfaced Four Sides) square stock in primed finger jointed pine & MDF — a versatile, straight-edged board used for window furring, jamb extensions, casing, and baseboard applications. Clean, stable, and paint-ready right out of the box.

  • Surfaced four sides for a smooth, consistent finish on all edges
  • Ideal for window furring and jamb extensions
  • Doubles as casing or baseboard trim when needed
  • Primed finger jointed pine — dimensionally stable and ready to paint

16 products

S4S Square Stock for Trim, Jamb Extensions, and More

S4S square stock is a practical choice when you need a smooth board with consistent dimensions and finished edges. Surfaced four sides provide a clean appearance and make the material versatile for a range of interior finishing applications. Use square stock for window furring and jamb extensions, or incorporate it into casing and baseboard projects when a straightforward, paint-ready trim solution is needed.

Our square stock options include primed finger jointed pine and MDF, giving contractors, builders, renovators and homeowners flexibility when completing interior trim work. Primed material provides a ready-to-paint surface, while the stable construction makes it well suited to detailed finishing projects. Whether you’re completing a window installation, extending a door or window jamb, or preparing trim throughout a renovation, S4S square stock offers a dependable material for getting the job finished neatly.

Need S4S square stock for your next renovation or building project? Visit Moulding & Millwork in Sydney, Nova Scotia, to explore primed finger jointed pine and MDF options. We supply homeowners, contractors, builders and renovators throughout Cape Breton Island, including Sydney River, North Sydney, Glace Bay and New Waterford. Contact our team to find the right square stock for your interior finishing needs.