Open-string Balusters

A staircase is a complex assembly, with dozens of joints that may loosen or fail over time. Railings are particularly prone to loosening. Sometimes it’s the posts anchoring ends of the railing, but more often the problem is with attachment of balusters (or spindles) to the treads of the steps. On an open-string staircase with two or three balusters per tread, balusters are of different length on each step, extending from tread to handrail. • In traditional construction, the bottom (hidden) portion of the baluster is cut as the pin of the dovetail, with a corresponding tail cut into the tread. The joint is carefully fitted and secured with a nail or screw. Then the joint is covered by a rounded bullnose. Over time, wood shrinks and may split, causing the railing to become unstable.

WRONG WAY TOENAILS & GLUE

Someone unfamiliar with the anatomy of the staircase often will toe-nail fasteners through the bottom of the baluster and into the tread. The nail or screw may not penetrate into the tread, however, but rather meet a void or the baluster’s dovetail pin. Some people squeeze glue into the gap between baluster and tread, but that only complicates subsequent repairs.

RIGHT WAY REATTACH BALUSTER TO TREAD

Instead, carefully remove the bullnose to reveal the dovetail joint. The fasteners into the dovetail pins may be nails or screws. If they have loosened or are damaged, replace them with modern screws. Small hardwood wedges should be tapped firmly into the space between the baluster pin and the cutout tail in the tread, to further strengthen the connection. Cut off the excess portion of the wedge, and reattach the bullnose.