The column shaft is the vertical body of the column, between the capital and the base. The shaft can be smooth (a simple cylinder) or fluted (vertical channels), with a range of options in between.
A smooth shaft is the most restrained option. A simple cylindrical shaft, with a flat surface from the base to the capital. The smooth shaft is suitable for modern, transitional, and restrained traditional interiors.
A fluted shaft is the most classical option. A cylindrical shaft with 20 to 24 vertical channels (flutes), typically 10 to 20 millimeters wide, separated by flat fillets. The flutes are typically stopped at the top and bottom (with a small horizontal band where the flute ends), which is a classical detail. The fluted shaft is suitable for traditional and formal traditional interiors.
A reeded shaft is a smaller-scale classical option. A cylindrical shaft with small convex vertical elements (reeds), typically 5 to 10 millimeters wide. The reeds are smaller and more numerous than flutes, and the overall effect is more refined. The reeded shaft is suitable for refined traditional interiors.
A paneled shaft is a more developed option. A shaft with raised or recessed panels, typically 50 to 100 millimeters wide, with a flat or stepped border. The paneled shaft is suitable for transitional interiors that want a more substantial column design.
A twisted shaft is a more decorative option. A shaft with a spiral or twisted surface, typically with 3 to 6 twists along the height. The twisted shaft is a Baroque detail, suitable for formal traditional interiors with a Baroque vocabulary.
For sourcing, PU column shafts are a stock product at most factories. The factory offers a range of standard shaft designs (smooth, fluted, reeded, paneled, twisted) in a range of standard diameters and heights. Custom designs and sizes are available on longer lead times.
A practical install note: the shaft is the main body of the column, and the install depends on whether the column is one piece or multiple pieces. A one-piece column (shaft, capital, and base shipped as a single unit) is installed by standing the column in place and securing it at the top and bottom. A multi-piece column is installed by setting the base, then the shaft, then the capital, with each piece glued to the next.
A practical note on the height. The shaft's height is typically 80 to 85% of the column's total height (with the base at 10 to 15% and the capital at 5 to 10%). A 2.4 meter column has a 1.9 to 2.0 meter shaft. The shaft should be proportional to the column and the room.
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Frequently Asked Questions
Q: What are PU columns?
A: PU columns are polyurethane molded columns — typically Tuscan, Doric, Ionic, or Corinthian — that replicate carved stone or wood at a fraction of the weight. They ship in two or three halves for assembly around an internal structural post or as a hollow decorative shell.
Q: Are PU columns load-bearing?
A: Standard decorative PU columns are not structural on their own. They are designed as a 2- or 3-piece shell that wraps an internal load-bearing post (steel, wood, or reinforced concrete). For structural applications, specify "structural PU columns" with an internal steel core — these are engineered and tested to published load ratings.
Q: How tall should decorative columns be?
A: For a standard 8 ft (2.4 m) ceiling, use a 96-inch (2.4 m) column shaft plus capital and base, totaling about 100–104 inches overall. For 10 ft (3 m) ceilings, use a 120-inch shaft. Custom heights are available up to 20 ft (6 m) for atrium and lobby installations.
Q: How do you install Column shafts?
A: Mount the base plate to the floor with anchor bolts. If structural, set a steel post first; if decorative, mount an internal PVC pipe for rigidity. Assemble the two or three PU column halves around the post, glue the seams with PU adhesive, and clamp for 30 minutes. Mount the capital and base with construction adhesive. Fill and sand the vertical seam, then paint.