Stair Base Rails and Infill, Grooved for 32mm and 41mm Spindles
The base rail sits on top of the string and holds the bottom of every spindle. Our white primed redwood baserail is 30 x 60 x 4200mm, grooved for 32mm or 41mm spindles, with matching infill to fill the groove between them.
Base Rails to order
Choose your options and add them to your basket. Pay online for priced parts and collect from Ashton-under-Lyne, or send the basket to us as a quote request.

White Primed Baserail
30 x 60 x 4200mm redwood, grooved for 32mm or 41mm spindles.

White Primed Infill
4200mm redwood fillet for the groove between spindles: 11.5 x 31.5mm for a 32mm groove, 11.5 x 40.5mm for a 41mm groove.
Choosing base rails
Grooved to match
Choose a 32mm or 41mm groove to suit your spindles, and use the same groove on the handrail.
Infill
Infill is sold in 4200mm lengths and cut to fit between each pair of spindles, in the handrail and the base rail.
Spacing the spindles
The gap between spindles must not let a 100mm sphere pass through. With 41mm spindles that means centres of no more than about 140mm.
White primed
Primed and ready for a top coat, to match our white primed handrails, newels and spindles.
Frequently asked questions
Do I need a base rail?
On a closed string staircase, the base rail is the neatest way to fix the bottom of the spindles. Without one, each spindle has to be cut and fixed directly into the string.
How many spindles fit on each tread?
Usually two per tread with a 41mm spindle, so the gap stays under 100mm. Some wider goings need three.
Is infill included with the base rail?
No, infill is sold separately in 4200mm lengths. Order it with the same groove size as your base rail and handrail.
Can I fit a base rail to an old staircase?
Usually, yes. The rail is fixed along the top edge of the outer string, so the string needs to be flat and sound along its length.
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