---
title: "Designer Rail Layout"
url: https://ipedeckingsource.com/RailInstall
description: "Marking sub-rails from the centre outwards at four and three quarter inch centres, and repeating the same layout on stair sections with a shallow drilled seat."
published: 2026-08-17
updated: 2026-08-17
---

# Designer Rail Layout

Published 2026-08-17

Laying out aluminium balusters on hardwood and softwood sub-rails, then repeating the layout on the rake of a stair section.

- 01Measure the sub-rails separatelyTop and bottom sub-rails are measured and cut separately. They are not assumed to be the same length, because the rail posts may not be plumb.
- 02Lay the sections out on the groundThe sub-rails for each section are laid side by side on the ground, splitting the difference in length where the two are uneven.
- 03Mark the centreMeasure to the exact centre point of the longest sub-rail and make a small pencil mark.
- 04Work outwards at 4-3/4 inch centresFrom that centre point, mark every 4-3/4 inches out to both ends. Those marks are the screw positions for the baluster connector, or the centre points for a 3/4 inch hole. The spacing gives a 3-3/4 inch opening once the balusters are in place, which is what keeps the opening under the four inch figure that most building requirements set.Marks are worked outwards from the centre of the longest sub-rail so that the two end bays match.
- 05Set the balustersOnce the connectors are mounted, or the holes are drilled in softwood, the balusters are placed at their marks.
- 06Build the stairs before the railStair sections, stringers and treads are installed before the rail goes on them.
- 07Repeat the layout on the stair sub-railThe sub-rails are placed on the stair section and the same measuring sequence is repeated along them.
- 08Drill the shallow seatDrill a very shallow 3/4 inch diameter hole at 90 degrees at each mark, using a Forstner bit in Ipe or a paddle bit in softwood. Held at 90 degrees, the shallow seat conceals the straight cut end of the baluster on the rake.
- 09Mount the connectors and fitAfter the holes are drilled, a connector is mounted in the centre of each one, and the sub-rail is ready to accept the baluster.