How to fit stair spindles and a handrail

Inspired by a helpful YouTube guide. This walk-through is based on the popular UK tutorial "How to Fit Staircase Spindles & Handrail Like a Pro" from Skill Builder, featuring Dan Cox. It covers the whole process including setting out the spacing, cutting the correct angles, and getting the handrail fixed securely. Definitely worth watching before you start measuring anything.

1. Remove the old spindles

Most older spindles are simply glued and nailed into a groove in the base rail and into the underside of the handrail. Work along from the top with a sharp chisel and a mallet, levering each one out. Take your time — the string board and treads are easy to mark if you get heavy-handed.

Once the spindles are out, clean up the grooves in the base rail and handrail. Old glue and wood splinters need clearing before the new spindles will sit properly.

2. Measure and plan the spacing

Building Regulations require that spindle spacing does not allow a 100 mm sphere to pass through. In practice this means your gap between spindles should be no more than 99 mm. Measure the total length of the base rail and work out how many spindles you need to meet that requirement.

Equal spacing looks best. Divide the rail length by the number of spindles to get your centre-to-centre measurement, then check the gaps that leaves. Adjust the number of spindles if needed — it is far better to do this on paper than to discover mid-job that you are 20 mm over the limit.

3. Fit the base shoe rail if your design needs one

Many modern spindle systems use a routed base shoe rail that sits on the existing string or tread, with spindles dropping into slots. If yours does, fix the base shoe first with adhesive and lost-head nails, making sure it follows the rake of the stair accurately.

On a straight stair this is relatively forgiving. On a winder stair with angled treads, take extra care with the template cutting — this is genuinely the trickiest part of the whole job.

4. Cut the spindles to length at the correct angle

Each spindle needs to be cut at the pitch angle of the stair at both ends so it sits plumb and fits snugly into the grooves. Set a sliding bevel to the stair angle and transfer that to your mitre saw.

Cut one spindle, test it in position, and check it sits properly before cutting the rest. They should all be identical length on a straight staircase, but small variations in the floor build-up mean it pays to check every few rather than assuming they are all the same.

5. Fix the spindles in position

Apply a small amount of wood adhesive to each end of the spindle before fitting. On systems where spindles pin into a base shoe and handrail groove, a small nail through the groove at an angle adds security. Keep the spindles plumb as you go rather than correcting them all at the end — it is much easier to adjust one at a time.

Wipe off any excess adhesive immediately. Dried PVA on visible joinery is one of those small irritations that stares at you every time you walk past.

6. Fit or refit the handrail

If you are keeping the existing handrail, clean it up, sand it down, and refit it once the spindles are in. If fitting a new handrail, cut it to length with the correct rake angle at each end and fix to the newel posts with a suitable handrail bolt or bracket.

The handrail should be between 900 mm and 1,000 mm above the pitch line of the stair for Building Regulations compliance. Check this at the top and bottom of the flight. If it falls outside that range on an existing staircase, note it but also be aware that older staircases often predate those regulations.

7. Sand and finish

Once everything is fixed and the adhesive has fully cured, give the whole assembly a light sand and apply your chosen finish — paint, stain, or varnish depending on the style. Two coats on the handrail is worthwhile since it takes the most wear.

Mind you, do not rush the finish coats. A handrail that is painted before the adhesive joints have fully hardened can creak for months afterwards. Leave it a full 24 hours minimum before any decorating.

When to call a handyman

Call Richard if the newel posts are loose or damaged, if the string board has rot or movement, or if you want the whole staircase refurbished as one job. Replacing spindles on an otherwise sound staircase is a satisfying afternoon — but the wider carpentry work around it is where it becomes a proper trade job.