1. Anatomy of a Staircase
Before you begin planning, it's helpful to know the terminology of the components that make up a stair balustrade:
Spindles (Balusters)
The vertical supports that fill the gap between the base rail and handrail, preventing falls and adding decorative style.
Newel Posts
The heavy, structural vertical posts positioned at the top, bottom, and turns of a staircase to anchor the handrails.
Handrail & Base Rail
The Handrail runs along the top of the spindles for grip. The Base Rail (or bottom rail) holds the bottom of the spindles.
The Rake & Landing
The Rake is the angled section following the steps. The Landing is the flat, horizontal gallery area at the top.
2. UK Building Regulations (The 100mm Rule)
When renovating or installing a new staircase in the UK, building regulations must be strictly adhered to for safety. Here are the two most important rules concerning balustrades:
The 100mm Sphere Rule
A 100mm sphere must not be able to pass through any gap in your balustrade. This is to prevent small children from getting their heads trapped or slipping through. Because of this, our formulas calculate a maximum gap of around 95mm between spindles to ensure you are safely within the legal limits.
- Handrail Height (Pitch): On stairs, the handrail height should be 900mm, measured from the pitch line (the line resting on the nosings of the treads).
- Handrail Height (Landing): On flat landings, the handrail must be a minimum of 900mm high.
3. Choosing Materials & Styles
Your choice of materials heavily impacts both the aesthetic and budget of your project. Standard spindle widths are typically 32mm, 35mm, 41mm, or 55mm.
Pine
Cost-effective and versatile. Perfect if you are planning to paint your stairs, or for a traditional look when stained or varnished.
White Oak
A premium hardwood. Highly durable with a beautiful natural grain. Best left unpainted and finished with oil or varnish.
Primed / Painted
We supply pre-primed timber, saving you time. Ideal for the popular modern look of white spindles paired with an oak handrail.
Glass & Metal
For a sleek, modern finish, we offer contemporary glass panels, glass clamps, and metallic spindles/balusters.
Other Timbers Available
We also supply parts in a variety of other high-quality timbers, including Hemlock, Ash, Walnut, Sapele, and Mahogany.
4. Measuring Guide
Getting your measurements right is key before ordering your stair parts. Keep these standard guidelines and measuring techniques in mind:
The "Two Per Step" Guideline
A general guideline for the rake (the angled run of the stairs) is to install two spindles per step (or tread). This spacing creates a balanced, traditional appearance and naturally keeps your gaps well within the 100mm building regulation limit.
Finding the Rake Angle
To use our configurator below, you will need the exact internal rake angle of your staircase. To find this, lay a long straight edge (like a piece of timber or a long spirit level) across the nosings (the front edges) of your stair treads. Place a digital protractor or use a clinometer/level app on your smartphone directly on top of the straight edge to read the angle.
Note: As a reference point, an average new build staircase typically has an external angle of 42° and an internal angle of 48°.
5. Spindle Layout Configurator
Bespoke Timber Spindle Layout Configurator
Use our advanced configurator to instantly lay out your timber spindles. We automatically calculate the optimal layout—aiming for the widest possible spacing while guaranteeing your gaps never exceed 95mm.
0 Total Spindles Required
0mm Exact Gap
0mm Horiz. C/C
0mm Pitch C/C
