A CPD course on designing stairs and handrails.
As an architect, how often do you have design issues when a staircase is being fitted?
Anything from handrails not fitting correctly, no room for the spindles on winder treads, unusual spacing of spindles round corners, etc.
As many architects are aware the staircase is often the largest and possibly the most complicated single item in a building, helping one traverse safely and comfortably from the bottom to the top of the property.
In this cpd course on staircase and handrail design, I will endeavour to give the key points in as brief an explanation as possible, this will not be in depth but hopefully, assist with the fundamentals of the staircase technical drawing.
I will concentrate on the technical key factors, that I have found as a handrailer are missed on many staircase drawings and by an unnerving amount of manufacturers.
As to whether you want stone or wooden stairs. Metal, glass or wood balustrading, the drawing principles will not change.
As with any drawing, the final dimensioning will be carried out by the manufacturer but with a few specifications, that they must follow or notify you of any changes, will make the staircase work, without having to be altered, once manufactured and fitted.
O.K. enough said, let’s get into it.
Key points for drawing stairs.
Quick tip: Draw the stairs before positioning doors etc.
It is much easier to move trimmers, door linings or windows than to shoehorn a staircase into the space that has been left.
2. The handrail centre line is king.
Handy to know.
Working on the next section down.
First and last riser positions.
Stringer face position, even with tread brackets.
Feature tread designs.
Feature tread construction.
Natural handrail height through turns and across landings.
Diminishing fliers, why use them?
Tread numbering.
Standard specification sheet for the staircase manufacturer.
Clad stairs.
1. Know the size and offset off the handrail support.
Why?
N.B. To get the handrail to flow correctly, the staircase is drawn from the handrail centre line down.
The support, whether it be timber spindles, glass, metal balustrade or any other form of support and its relationship between the handrail and the edge of the staircase will determine where the edge of the staircase, newel post and riser positions may be set.
This will also let you design any feature treads to be able to carry a feature termination to the handrail.
The handrail is the main part of the staircases that may be 3 dimensional and getting the flow correct will enhance the look of the stairs.
Solution.
Decide on the support that is going to be used and its location on the staircase.
This may be timber spindles set in a traditional position on the treads, timber spindles side mounted against the stringer, cast balusters set into the stringers but projecting away from the edge of the stairs, glass panels side mounted to the stringers or any other option you may want.
Each of these will have a different offset from the stringer face and therefore the stringer will need to move relative to the handrail centre line.
In the gallery, we have a few options showing how the spindles or balusters may be set in different positions.
The following section – The handrail centre line is king. will explain how this works.
How.
To calculate the support offset.
This is done by calculating the distance from the centre line at the top of the support to the stringer face.
For any surface mounted, straight support, this is very simply measuring the distance from the support centre line or half the support width to the position of the stringer face.
For side mounted, straight support, this is the same but the stringer is offset to the opposite side of the support.
For any curved support, these are normally only used on side mounted supports. This is the distance from the centre line at the top of the support to the stringer mounting face at the bottom of the support or any bracket that may be used for holding the support. e.g. Brackets for holding glass.
2. The handrail centre line is king.
For geometric flights with a well.
Why?
The stairs are drawn from the handrail down.
When a staircase is designed, unless it is a straight flight with closed strings and set between newels. Then the handrail flow and spindle or vertical support for the handrail, controls the stringer and riser positions.
When this is not done there is a probability that on staircases with winders, the stringer and riser positions will not be constructed correctly to support a flowing handrail or the spindles may not have a tread space large enough to seat the spindles, without interfering with the nosing projection from the tread above.
Solution.
Determine the layout for the flight of stairs in plan view, initially, you can use the edge of the stairs in plan view as the centre line of the handrail.
When a large stairwell is available there will be plenty of space between any adjacent flights or landings.
When a narrow stairwell is to be allowed for, a diameter with a minimum of 1/2 a going between handrail centre lines should be allowed for in order for the handrail to be able to turn through 180º turn.
A diameter equal to a full going minimum is a better space to leave between the handrail runs.
When drawing the stairs, the nosing or any projection is not part of the calculation, as at this and the manufacturing stage, these are for all intent and purpose a decorative detail and not part of the calculations.
More about this on our page:
Once the plan has been drawn, with the handrail centre line used to represent the edge of the staircase, the offset between handrail and stringer face can be used to determine the correct stringer position.
The spindles can now be drawn onto the staircase plans, to confirm that the spindle spacing works and that the spindles can be placed without obstruction from risers or nosings.
With the plans now drawn it is best to draw the stretch out and confirm that the handrail has the flow expected.
The next section shows how the stretch out or development of the flight is done.
How.
Once you know the area the staircase is going to occupy and the initial plan layout, the first stage is to consider roughly where you would like the stairwell or any edges of the staircase to reside.
The second stage is to draw how the handrail will be set over these proposed edges of the staircase.
When drawing for straight flights, that run close and parallel to each other, there are two ideal positions for the handrail centre line offset.
- Half a going’s distance between adjacent runs.
When going from flight to flight e.g. at half space landings, this will maintain the same pitch through the turn as down the flights. When coming to a full landing, the handrail will come to level at the end of the turn.
2. A full going’s distance between adjacent flights.
This will allow the handrail to come to level mid turn or create a natural flow when coming to a landing.
More about this here:
On all flights with geometric handrails.
The top and bottom riser position in relation to the landings is important, to maintain the handrail’s natural flow, these should be set in front of the landing trimmer, allowing enough space for the drum that will be the stringer or landing fascia through the turns.
The only tread that should sit on top of a landing is a feature tread. This is normally set on the main entrance level.
This is due to landings being part of the staircase. The landing links the different flights together, and is, therefore, to be considered as an unusually shaped tread, hence the handrail flight halfway through a going is equal to the handrail height over the landings.
Once the handrail positions have been drawn the positions of the stringer faces and landing fascias can be calculated by transferring the handrail centre line down through the handrail support.
For flights set over each other.
With newels and no well.
Why?
When the flights sit over each other, the handrail centre line is still as important as it is with geometric flights, as this will set the positions for the stringer faces and landing fascias.
Even with closed string flights, the stringer may be set centrally in the newel but the landing fascia position and landing nosing will still need to be calculated.
When this rule is not followed then the landing fascia could very quickly and easily end up in the wrong position and there will be nowhere to fit the base of the spindles or even worse there could be a finger trap as you grasp the handrail walking up the flight.
If nothing else it will make it hard to fit the handrail to the newel posts and may not leave a clean way of finishing the handrail on the landing as it comes back in, under the flight above.
More about diminishing handrails here:
Solution.
As with geometric flights you will still need to know the size of the support, as this will still control the position of the landing and stringer faces.
As with geometric flights, the handrail centre line coming down through the support, still controls the edges of the staircase and the landing.
When newel posts are used we know that the handrail will sit centrally on the newel post and the support will also follow this line down.
therefore the stringer face or landing fascias can be calculated from this line.
By aligning the stringer face and landing fascias correctly, the handrail coming up the flight will intersect with the ceiling line correctly and the handrail coming along the landing will join into the underside of the flight above correctly.
How.
Working from the handrail centre line, set the newels and spindles centrally over the centre line, this will give you the face position for the spindles.
By using the outside face of the spindle, the outside being the face farthest away from the treads or landings.
This will be the face of the stringer or landing fascia under the spindle.
The centre line of the spindles and newel posts on the flights and landings should be set directly over top of each other; to ensure that the handrail will work correctly.
Should a stairwell be required, it is recommended a minimum of half a going is used between handrail centre lines; anything smaller than this will probably create problems either in manufacture or while using the handrail.
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3. The staircase stretch out.
Why?
The staircase stretch out will reveal a lot of information about the staircase design.
By drawing the stretch out, you will be confirming that what you have drawn on plan view, will work in elevation.
Just drawing a side elevation and front elevation will not always show how the staircase works as it turns through a corner.
Developing the staircase into a 2D drawing from a perpendicular view at any point through the stairs, gives a far greater visual explanation of any anomalies that may occur before the drawings are sent for manufacture.
Any transitions in pitch can be seen, allowing for alterations at the drawing stage.
Spindle heights, Stringer to landing fascia transitions, handrail flow, etc. can be confirmed.
Solution.
By opening the staircase out into a 2D elevation, it is possible to see how the flow of the stairs will work.
This is useful for both geometric and flights with newels,
Geometric.
When working on geometric flights, the stretch out will allow you to see how the handrail flows and be able to confirm its height over the risers to keep it legal.
It will also show the how the stringers flow through the flight and how the underside of the flight interacts with the landing ceilings.
N.B. For any staircase that has the spindles set on the treads, you will need to know the nosing projection.
Another benefit is being able to confirm the spindle’s positions and heights through the turns, ensuring the tread ends are big enough to seat the spindles without overlapping the tread nosings above.
Neweled.
When working on flights with newels it will allow you to calculate the turn lengths for any newels and how the handrail may intersect with the newel, either by a handrail block over the turn or the main newel stub itself.
This will help avoid having the handrail intersecting with the newel turn when not expected.
The handrail flow may be drawn up for flights that are going to have a goosenecked handrail where the handrail runs over the top of the newels.
How.
Geometric stretch out.
There are two ways of doing this.
A. The original way, as with pen and paper.
B. The new way using 3d cad software.
You can read more about this here:
I will run through some of the basics here, I am working on a page that will show various staircase layouts and how to create the stretch outs.
I have set the page for this and started on it here.
Why not pop over and see how it is going?
No matter the layout, once you understand the principles, drawing the stretch outs will be the same for any staircase style.
An example: drawing a 180º wreathing turn, levelling mid-turn.
The traditional way.
Using the tangent handrailing way of creating the stretch out may not be as accurate as the cad way but is close enough for when the staircase is made in the traditional handcrafted way by joiners; as they will smooth the slight idiosyncrasies by eye, during the manufacturing process.
This is close enough to confirm the layout of the staircase and handrail, ensuring there is room to seat spindles on winder treads without the nosing from the tread above interfering.
This is also suitable to confirm the handrail and bottom of stringer flow.
Although not as accurate as the cad method this method is a good way of getting a quick idea of how the staircase will work and it can be easily drawn up on a drawing board without the use of computers and cad software.
once you have used this method for a few weeks it will become evident where any discrepancies may lie and how to overcome them.
I will try to point these out below.
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An example: The stretch out for neweled flights.
A staircase with newels in the winders.
So, don’t think you can get away without doing the stretch out for straight flights with newel posts at changes of direction.
The stretch out will allow you to determine the height and turn length of the newel posts.
It will show how the handrail connects to the post whether it be into the stub, into a handrail block or over the top for goosenecked handrail.
Here we will look at a simple 90º turn with 3 winders and a newel post between the straight closed strings.
Plan view of the flight with newels.
Here is the plan view for the flight in the image above.
The top and bottom newel posts are shown as a square but if we wanted a turned section in the newel post, as in the newel post towards the top of the flight, in this image, goings 7 – 11 are in the newel post area.
Then it would be better to know the block lengths, turn length and positions, this will allow for the post to be manufactured as one and morticed to accept the stringers and handrail.
Transferring the riser lines to the handrail centre line.
The first thing to do is to extend the riser lines to the handrail centre line.
These contact point between handrail centre line and riser line, will need to be sprung from around any corners, back to the stretch out line.
This will give you the positions from which you can carry the riser lines up to the stretch out.
Transferring the riser lines to the stretch out.
Once the riser lines have been bought up to a single base line for the stretch out, they can be transferred up through the stritch out riser spacings.
This will then allow you to darw in the giongs and rises to create the 2d elevation of the staircase.
The next stage is to add the top of the closed string: in traditinal joinery the margin peice is set at 1 1/2″ – 38mm or a distance of above the top of the riser where it meets the going.
The bottom of the stringer may also be drawn in, again in much traditional joinery the stringer was approx 11″ deep.
The thickness of the newels can be transferred up through the stretch out, to show the riser and nosing positions around the newel.
The handrail may now be drawn in between the newels at the correct height above the pitch line.
N.B. The pitch line for the handrail in some local bylaws, may be specified differently to that for manufacturibg calculations, e.g. from the front of the nosing.
With the above drawn in it is now possible to determine newel stub, newel turn and handrail block lengths and positions.
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The bit I am working on.
The landing is a tread.
Why?
The staircase may be made up of many flights but is only a single staircase.
Even when only a single flight, it is good practice to consider the landings as treads.
These may be oddly shaped treads but they still need to be drawn and calculated as part of the staircase.
This will help determine the handrail flow for geometric flights and the handrail block position for flights with newel posts or handrails that run over newel posts.
When the flights are considered to be different staircases, there is a very good chance that their positioning relative to each other may be incorrect.
Quarter space and half space landings are still in the flight and not a platform between two straight flights.
Solution.
Think of the landing fascia as the stringer face and the landing nosing as a tread nosing.
By drawing the landings in, as treads, all the landing components will be taken into consideration with the staircase.
This should remove the chance of other trades, that generally do not have knowledge of staircases, trying to link two flights together.
As the turns or drums are often in the landing tread, it will allow the correct positioning of any trimmers that are required to be accommodated before the staircase arrives on site to be fitted.
Planning the landing fascias and nosings will mean that the spindles, metal balusters, glass or whichever trim you are using on the stairs will be catered for.
How.
By drawing the flights that the landing is sitting between and deciding on the shape of the landing.
The landing connects the riser of the flight beneath it, to the riser of the flight above it, as it does with a standard going.
With the riser positions for the flights leading into and out of the landing, the landing shape and therefore landing fascia and nosings may be calculated.
The landing shape will depend on whether the flights are set over each other, have a small well, a larger well or an atrium style of landing.
We covered much of this setting out, in a previous section:
2. The handrail centre line is king.
The handrail over the landing may be kept at the same height as it is at the front of a tread, up to any height required, it will naturally lift to the same height as it is midway across the tread.
Read more about this here:
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