Stair Installation

Stairs are the one place in a house where getting the math slightly wrong becomes a safety problem. Code here caps the riser at 8 1/4 inches, requires at least a 9-inch tread, and allows no more than 3/8 of an inch of variation between the tallest and shortest riser in a flight. People trip on stairs because one step is a quarter inch off from the others — your foot learns the rhythm on the first two treads and then finds one that breaks it.

Squeaks come from treads that were nailed instead of glued and screwed, or from a riser that is not drawn tight to the back of the tread above it. When we rebuild a flight we glue every joint with construction adhesive, screw up through the stringer wherever there is access from below, and shim any gap between tread and stringer before it is fastened. A staircase should be silent.

Most of what we do is carpet-to-hardwood conversion. The treads under that carpet are almost always construction-grade pine that was never meant to be seen. We either cap them with proper hardwood retread stock or replace the treads outright. Sanding and staining builder pine gets you a staircase that looks like builder pine somebody stained.

A railing has to resist a 200-pound load applied in any direction at the top. That load travels into the newel post, and the newel post has to be bolted through into a joist or a blocked bay — not toe-nailed to a tread. We open the ceiling below when that is what it takes. A handrail that wobbles is not a finish complaint; it is a failure of the one thing somebody grabs when they slip.

A straight flight of fourteen treads, retreaded with new risers and a new railing, runs four to six days. The stairs are out of service for most of that. If they are the only way up, we work out access before anyone starts demolition.