Carpentry Guides

Repairing Wooden Staircase Balusters

Balusters, also sometimes known as Spindles, are the upright infill bars on a wooden staircase. Over time, the balusters can become loose, cracked or even broken completely, and will need repairing or replacing to make the staircase safe.

The Balusters on a wooden staircase are fixed in one of two ways: either with a nail driven through the baluster into the handrail at an angle, or they sit in a groove on the bottom of the handrail with fillets of wood between each one to hold them in position.

Problem 1: Loose Nails

If your wooden staircase is the type which is nailed, you may find that nails work loose over time. In this situation, use some pliers to remove the loose nail, and replace it with a slightly longer and thicker nail. If you can’t remove the old nail (it is sometimes awkward to get a good grip on nails in these situations), drive a new nail through the baluster at a different location.

Make sure the baluster is pushed firmly against the underside of the handrail before driving in your new nails. Repeat this process for each loose baluster.

Problem 2: Loose or Missing Wooden Fillet

If you have a staircase which uses the fillet method of construction, you may find that the fillets loosen or fall out completely. If the fillet which has fallen out is sound, you can reuse it. If not, or if it somehow gets lost, you will either need to buy a new fillet from a local DIY store (although these might not always fit your particular staircase) or cut a new one to fit.

Make sure the baluster has not slipped out of position within the groove on the underside of the handrail, and make sure it is pushed in as tight as possible. Replace the fillet into the groove and nail it into place. You can use a nail punch to drive the heads of the nails below the surface of the wood.

Problem 3: Split or Broken Baluster

Repairing BalustersIf a wooden baluster has split, you may be able to remove it and then repair it using clamps and glue. If the split is particularly bad, or if the baluster is completely broken, you will need to replace it. Depending on the staircase construction, you will either need to remove the nails holding the baluster in place, or remove a fillet of wood from the underside of the rail.

If you think you can repair a cracked baluster, apply wood glue to the crack and use padded clamps to close the crack until the glue sets. It is a good idea to check you can close the gap before applying glue, as it might just be too large. Check the baluster is straight and not twisted before the glue sets, and correct the problem if it is. Once the glue has set, replace the baluster, nail it into place, or replace the wooden fillet.

If the baluster is broken beyond repair, you will need to replace it. You can buy almost any style of wooden baluster from DIY stores or online from staircase component specialists. Measure your existing balusters carefully before ordering a replacement. When the new baluster arrives, carefully trim the ends if needed (a new baluster will normally need to be trimmed to fit), ensuring that if it is carved, the carved section lines up with the existing spindles. Fix the new baluster in place with a nail, or a fillet, depending on the construction of your staircase.

Expert Tip

A quick way to tighten a baluster that’s loose at the bottom is to drill two pilot holes at angles into the baluster, and then drive two nails through the baluster and into the string. You can also use this method if the baluster is loose at the top, driving the nails into the underside of the rail. 

Know Your Staircase

There are several strange terms associated with staircases. Knowing the difference between the nosing and the string is important if you plan to do any repair work on your own staircase.

Baluster – The vertical member between the handrail and base rail. Balusters can be plain or decorative, squared or rounded.

Bullnose Step – Usually the bottom step of a staircase. One or both ends of the step are rounded so that there are no sharp corners.

Closed String – A string which has been capped on the outside face with a straight strip of wood, so that the profile of the steps cannot be seen from the side.

Cut String (Open String) – A string with the upper edge cut into the shape of the treads and risers.

Going – The horizontal distance between the first and last riser of a staircase. The individual going of a step is the distance between the face of one riser and the face of the next. This should be no less than 220mm on a domestic staircase.

Newel (Newel Post) – This is the thick upright post at the bottom and sometimes the top of a staircase, onto which the handrail and string are attached.

Nosing – The edge of an individual tread which projects out over the riser below it.

Rise – The vertical distance between the floor and the landing onto which the stairs lead. The individual rise of a step is the vertical distance between the top of one tread and the top of the next.

Riser – The piece of wood which forms the vertical part of the step. Should not be more than 220mm in a domestic setting.

Stairwell – The void in which the staircase sits.

Step – One tread and one riser combined makes one step.

String – The sides of a staircase, onto which the risers and the treads are attached. See Cut String, Closed String and Wall String for more details.

Tread – The horizontal part of a step (the bits your feet go on…)

Wall String – A string which is fixed flush the wall.

Winders – Triangular shaped steps used for changing the direction of the staircase smoothly through 90 or 180 degrees.