Joining Split Fiberglass Columns

Joining Split Fiberglass Columns
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Split columns are manufactured to go against a wall or surround structural beams and are installed similarly to un-split columns. They are NOT loadbearing. A split column kit should be used to reassemble the shaft halves. If installing more than one split column, be sure to mark the column halves to prevent mismatching them. 

1. Measure the overall opening height.

2. Always trim fibreglass columns from the bottom of the shaft using an abrasive cut-off blade. Make final adjustments with a belt sander or rasp. 

3. Ensure the adjoining surfaces are clean and dry. Apply a bead of polyurethane adhesive to all connecting surfaces on both halves. 

4. Align the column halves together around the structural support and join together. 

5. Secure using the straps provided in the Split Column Kit. Place straps approximately 18" apart and pull tight. 

6. Larger diameter columns require joining two straps together. Temporary shims may be required to align the column seam. The shims are removed after the polyurethane adhesive has cured. 

7. Install the joining plates at the top and bottom of each seam. Pre-drill pilot holes through the column and install the rust-resistant screws provided in the Split Column Kit. NOTE: Plates are not required for split wood columns. 

8. Allow the polyurethane adhesive to thoroughly cure and cut away the straps. Use a putty knife to remove any excess polyurethane adhesive. Use automotive body filler to cover any voids along each seam. Sand both seams smooth. 

Caps and Bases

  • Join the base halves together with polyurethane adhesive and secure in place with rust-resistant screws
  • Join the capital halves together with the polyurethane adhesive and secure them in place with rust-resistant screws
  • Apply paintable silicone sealant at the joints between the base, shaft and capital.
    Refer to Installing Round Fibreglass Columns for more information on capital and case installation and finishing instructions


  • Store all wood columns in a cool, dry and well-ventilated area. 
  • All split columns, capitals and bases must be primed with one (1) coat of an exterior oil-based primer and then painted with two (2) coats of exterior oil-based paint. NOTE: the seams where glue is to be applied are NOT to be primes or painted. 
  • The end grain at the bottom of the shaft must be sealed and painted to protect the column from moisture.
  • Apply the oil-based primer and paint with a brush to best protect the column from moisture. Follow the paint manufacturer's instructions for best results. 
  • Adequate ventilation is a necessity in the installation of wood columns. Ventilation must be provided for at the top of the column by a recessed soffit. Ventilation will be provided at the bottom of the column by the precut openings in the plinth. 
  • Install flashing with all split capitals (Refer to Flashing Installation Instructions) taking note not to disturb column ventilation.

Want to print these instructions? Download a PDF version here.