Staircases BCGCA3016B
Types of Stairs Straight Open Riser Dogleg Closed Riser Definition – Flights Between Landings 1 Flight 2 Flights
Straight Open Riser
Stair Types
Double Closed Stair Stair Types
Double Open Sided Stairs
In this case one side is closed while the other is open
Note The Bracketed Stairs refers to decoration & Cut String Also Known as Cut String
Quarter Turn Stair Open Newel Stair
Spine String Stair
Types of Stairs Geometric Spiral
Types of Stairs Quarter Turn
Parts of Stairs
Half Space Landing Change stair direction 180⁰ Landing width = width of stair (min 750mm) Used in Dogleg Stairs
Quarter Space Landing Change Stair Direction 90 ⁰ Landing Width & Length = Stair Width Forms Quarter Turn Stair (min 750mm)
Intermediate Landing Allows the Stair to continue in same direction Required where more than 18 Risers May be used to give a rest Width = Stair Width Length = Stair Width or greater
Quarter Space Landing
Quarter Turn Stair
Winders
Materials Used in Stair Construction Timber Metal Stone Glass
Timber Stairs
Metal Stairs
Concrete Stairs
Stone Stairs
Glass Stair
Combination of Materials
Definitions
Rise & Going must stay the same within flight
BCA Requirements
Stair Requirements
Winders Treads that are tapered Must have same rise as the flights Maximum of 3 treads per quarter turn Must be same width at centre on widths < 1m If stair > 1m same width 400mm from inside handrail
Winders
Calculate Stair No Restriction on Going Determine Total Rise= 2700 Select suitable Rise Say 175mm Divide Total Rise by Rise = 2700/175 = Either 15 or 16 Risers = 2700/15 = 180mm 2700/16 = mm Use 180mm is closer to 175mm Best Going 2R + G Between 550 to 700 Midpoint = 625
Determine Best Going BCA states that going must be within the range 2 x Rise (R) + Going(G) = 550 to 700 We can assume that the best answer is the Midpoint ( )/2 = 625 Best Going2R + G = 625 Best GoingG = 625 – 2R
Calculate Stair No Restriction on Going Determine Total Rise= 2700 Select suitable Rise Say 175mm Divide Total Rise by Rise = 2700/175 = Either 15 or 16 Risers = 2700/15 = 180mm (Use) 2700/16 = mm Best Going 2R + G Between 550 to 700 Midpoint = 625 Either Rise 180 Going 265 Determine Best Going 2R + G = 625 G = 625 – 2R Best Going for180 Riser265 = 625 – 2 x 180
Calculate Stair No Restriction on Going Use Rise 180 Going Risers 14 Goings
Calculate Stair Restriction on Going Preferred Rise 175mm Divide Total Rise by Rise = 2700/175 = Either 15 or 16 Risers = 2700/15 = 180mm 2700/16 = Use 180mm Determine Best Going 3800/14 = x 180 = (Closest) 3800/15 = x = 591 Best Going 2R + G Between 550 to 700 Midpoint = 625 Use Rise 180 Going Risers 14 Goings
Calculate Stair Flight with Quarter Turn Stair width 900mm Once an Intermediate Landing is introduced the top flight becomes constrained
Calculate Stair Flight with Quarter Turn Stair width 900mmPreferred Rise = 165mm 2700/165 = /16= (3.75 Diff) /17= (6.176 Diff) Use Rise = Best Going = 625 – 2R = 625 – 2 x = /287.5 = /6 = 300 (12.5 Diff) 71800/7 = ( Diff) Rise = Going = 300 Best Going 2R + G Between 550 to 700 Midpoint = 625 G = 625 – 2R
Calculate Stair Flight with Quarter Turn Stair width 900mmPreferred Rise = 165mm 2700/165 = /16= (3.75 Diff) /17= (6.176 Diff) Use Rise = Best Going = 625 – 2R = 625 – 2 x = /287.5 = /6 = 300 (12.5 Diff) 71800/7 = ( Diff) Rise = Going = 300 Best Going 2R + G Between 550 to 700 Midpoint = 625 G = 625 – 2R
Calculate Stair Constrained Flight with Quarter Turn Stair width 900mm From Previous we know 15 Risers at 180 Length of 1 st Flight = Divide by Best Going = 1800/265 = 6.79 Going Either 1800 /6 = 300mm 1800/7 = 257mm is Closest to 265 Best Going 2R + G Between 550 to 700 Midpoint = x 180 = 265
Calculate Stair Constrained Flight with Half Space Landing Stair width 900mm Preferred Riser 170mm 3600/170 = /21 = /22 = Use mm Best Going = 625 – 2R = 625 – 2 x = Length of 1 st Flight = 4050 – 900 = 3150 Divide by Best Going = 3150/ = /11 = /12 = Use
Calculate Stair Constrained Flight with Half Space Landing Stair width 900mm Preferred Riser 170mm Rise mm Going
Calculate Stair Constrained Flight with Quarter Turn Winders Stair width 900mm Preferred Riser 170mm 4100/170 = /24 = /24 = 164 Use Rise Best Going 625 – 2R = BG 625 – 2 x = / = /9 = (USE) /10 = 265 Rise Going
Calculate Stair Constrained Flight with Quarter Turn Winders Stair width 900mm Preferred Riser 170mm 4100/170 = /24 = /24 = 164 Use Rise Best Going 625 – 2R = BG 625 – 2 x = / = /9 = (USE) /10 = 265 Rise Going
Calculate Stair Constrained Flight with Half Space Landing Stair width 950mmPreferred Riser 170mm 3400/170 = /20 = 170 Rise Best Going = 625 – 2R = 625 – 2 x 170 = /285 = /8 = 300 (15 Diff) 92400/9 = (18.3 Diff) Rise 170 Going 300
Calculate Stair Constrained Flight with Half Space Landing Stair width 950mmPreferred Riser 170mm 3400/170 = /20 = 170 Rise Best Going = 625 – 2R = 625 – 2 x 170 = /285 = /8 = 300 (15 Diff) 92400/9 = (18.3 Diff) Rise 170 Going 300 With all examples either answer will comply and you should consult with your client and/or Architect
Determine Steel Square Mathematically 40mm Margin
Determine Steel Square Mathematically
Zoom In Stair Pitch = ⁰
Determine Steel Square Mathematically Margin Line Stair Pitch = ⁰
Determine Steel Square Mathematically This angle must be the same Stair Pitch = ⁰
Determine Steel Square Mathematically This angle must be the same Stair Pitch = ⁰ Sin Ѳ = Adjacent / Hypotenuse = 40 ÷ X X = 40 ÷ Sin X =
Determine Steel Square Mathematically This angle must be the same Stair Pitch = ⁰ Sin Ѳ = Adjacent / Hypotenuse = 40 ÷ X X = 40 ÷ Sin X = 81.13
Determine Steel Square Mathematically Set Out For Steel Square Going Going + Margin ÷ Sin Ѳ = ÷ Sin 29.54⁰ = mm Ѳ
Determine Steel Square Mathematically Set Out For Steel Square Rise Ѳ
Determine Steel Square Mathematically Set Out For Steel Square Rise Ѳ This Angle must =
Determine Steel Square Mathematically Set Out For Steel Square Rise Ѳ This Angle must = This Angle must = 29.54⁰ Y = 40 ÷ Cos 29.54⁰ Y =
Determine Steel Square Mathematically Set Out For Steel Square Rise Ѳ This Angle must = This Angle must = 29.54⁰ Y = 40 ÷ Cos 29.54⁰ Y =
Determine Steel Square Mathematically Set Out For Steel Square Rise Ѳ Rise + Margin ÷ Sin Ѳ = ÷ Sin 29.54⁰ = =