A composite column is a modular column system, made from multiple PU components that are assembled on site. The system typically includes a base, one or more shaft sections, a capital, and sometimes a necking. The components are designed to be assembled into a complete column, with the connections hidden by the overlapping profiles.
The advantage of a modular system over a one-piece column is the shipping efficiency. A 3 meter one-piece column is difficult to ship (it doesn't fit in a standard container), but a 3 meter modular column can be shipped in components that fit in a standard container. The components are also easier to handle on site, with two people able to carry each piece.
The most common modular column application is a residential entryway with a 2.7 to 3.6 meter column. The column is assembled from a base, a shaft (or two shaft sections for taller columns), a necking, and a capital. The components are glued together with construction adhesive, and the joints are hidden by the overlapping profiles.
A second common application is a commercial lobby with a 3.6 to 4.5 meter column. The taller column is assembled from a base, two or three shaft sections, a necking, and a capital. The components are sized to fit a standard container, and the assembly is done on site.
A third common application is a custom-height column for a specific project. The column is assembled from a base, a custom-length shaft, a necking, and a capital. The custom shaft is cut to the right length, and the assembly is done on site.
For sourcing, composite columns are a stock product at most factories that produce classical columns. The factory offers a range of standard component designs (bases, shafts, neckings, capitals) in a range of standard sizes, with quick lead times and competitive pricing. Custom components are available on longer lead times.
A practical install note: a composite column is assembled on site, with each component glued to the next. The base is installed first, secured to the floor with construction adhesive and mechanical fasteners. The shaft sections are installed next, glued to the base and to each other. The necking and capital are installed last, glued to the top of the shaft. The joints are filled with paintable caulk, and the painter's topcoat goes on the next day.
A practical note on the assembly. The composite column should be assembled on a flat surface (the floor) before being stood upright. The components are glued together, the adhesive is allowed to set, and the assembled column is then stood in place. This approach ensures that the joints are tight and the column is straight, and it's much easier than assembling the column in place.
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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 Composite columns?
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.