The easy way.

Getting the rebate size.

How to determine the diminishing handrail rebate size.

When the stringers are set correctly it is very easy to determine the vertical and horizontal cut lines to house the handrail around the stringer or ceiling line.

The vertical cut.

This is achieved by carrying the stringer face, up through the handrail.

The horizontal cut.

The easiest place for this is the widest part of the handrail.

When the staircase is set out correctly, the same rebate will work for: The closed string, under stringer, under ceiling lines, with or without newels.


The only exception is for the diminishing handrail under a cut string.

Please see; under the Cut string, below.

Rebate cut quick guide.
Rebate cut – quick guide.

Further explanations of the setting out.

Handrail diminishing Under stringer.

Under the closed string.

On closed strings, it is fairly straight forward to determine the rebate size, every component that contacts the newel will have its centre line aligned with the newel centre line.

Therefore by drawing the handrail and stringer positions onto the newel, you can calculate the vertical cut line into the top of the handrail profile, by offsetting from the newel centre line by half the spindle thickness.

The diminishing closed string is the only time you do no use the spindle width; as the spindle may be wider than the stringer and be set on a stringer capping. The landing or under ceiling line you will still use the normal method.

stringer handrail position
stringer handrail position against newel post.

Under the cut string.

To get the handrail rebate cut lines for the cut string staircase you will have to adjust the stringer position to suit.

The landing face of the cut string will move dependant on spindle size, therefore the landing face position of the stringer will move with the spindle size and the stringer centre line will more often than not, not align with the newel centre line.

To see how to set out the stringer position.

Diminishing handrail - cut string.
Diminishing handrail – cut string.

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Under the ceiling or landing.

To get the handrail rebate vertical cut line for under a ceiling or landing edge, you will need to find the spindle offset from the ceiling to the centre line of the spindles.

This will change dependant on where the ceiling to wall face is set.

more often than not the easiest way to get this dimension is to set the handrail on the nosings and butting up to the underside of the ceiling, then mark the handrail in position.

handrail under ceiling rebate
Handrail rebate under ceiling or landing.

Here you can see the handrail laid across the nosings and butting up to the ceiling line.

When closed string stairs are used, lay the handrail centrally over the stringer to get the position.

This makes it easy to get the position at this point but do confirm that the stairs run parallel with the ceiling line above.

vertical cut under landing
Vertical cut position under landing.

Getting the rebate size.

Vertical cut.

The easy way to get the rebate size is to draw the components onto the newel or draw a rod out.

To get the dimension across the handrail for the vertical cut down through the top of the handrail.

  1. Draw the newel width with its centre line.
  2. Draw the stringer width with its centre line set over the newel centre line.
  3. Draw the handrail profile with its centre line set over the newel centre line.
  4. Draw a line from the landing stringer face to the handrail profile, this will be the vertical cut line.
  5. Confirm the distance from landing stringer face to edge of newel.
Vertical cut position closed string.
Vertical cut position closed string.

Common to all.

Horizontal cut.

The horizontal cut is much easier to achieve.

This may be set at almost any point but it is worth remembering two things:

  1. when cut above the widest point of the handrail it may lead to awkward parts to polish and create a dust trap.
  2. Is the rebate deep enough to cover any molding to the bottom of the stringer, if not it may leave an ugly detail that is once again a dust trap and hard to decorate.
Horizontal cut position closed string.
Vertical cut position closed string.

The mitre cut.

Once the rebate has been set for the diminishing parts of the handrail, It is time to join the diminishing handrail into the flat or horizontal section of handrail.

The mitre will also have to have the rebate cut into it so it too can fit around the bottom of the stringer.

The easiest way I have found to do this, is to cut the two mitred ends, butt them up against each other and draw the rebate lines across through the mitre then cut the small rebate out with a tenon saw.

rebate the mitre.
Rebate the mitre.