What is a straight flight staircase?

A straight flight staircase (straight-run stair) rises in one straight line, without any turn. Because there are no winders, every tread has the same depth. A stair with a 90 degree turn at the top or bottom is a quarter-turn stair. The Dutch term is steektrap.

Pros and cons

• Pros: comfortable and safe to use, simple to build and usually the cheapest type. Furniture is easy to carry up.
• Cons: it takes up the most length, in the room and in the stairwell opening above. A long flight may need a landing halfway.

Worked example

Floor-to-floor height: 2,600 mm.

1. Aim for a rise of about 185 mm: 2,600 / 185 = 14 risers of about 186 mm.
2. A straight flight with 14 risers has 13 treads; the upper floor is the last step.
3. With a going of 240 mm the flight is 13 × 240 = 3,120 mm long on plan.
4. Check with the step formula: 2 × 186 + 240 = 612 mm, a comfortable stride.

Application

1. Measure the space first. If a straight flight does not fit, a quarter-turn or half-turn stair is more compact.
2. Check the rules. Limits for rise, going, pitch, width and headroom differ by country: Approved Document K in England, the Bbl in the Netherlands, DIN 18065 and state building codes in Germany. Use the current edition for your location.
3. Plan the headroom. The opening in the floor above must be long enough that you do not hit your head when walking up.
4. Fit a handrail. Even a straight flight needs a sturdy handrail.

Common mistake: squeezing the dimensions to fit the space until the stair is too steep. Start with comfortable dimensions and then see whether the stair fits.

Related terms

• Stair step formula
• Riser height
• Going depth
• Walking line on a stair
• Landing
• Open riser staircase
• Spiral staircase

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