STAIRS3rd YEAR TRADE
Lesson Two
M.S. MARTIN
March 2005
Reviewed 2011
M.S. MARTIN
March 2005
Reviewed 2011
Review Calculations• Determine suitable rise &
going of step to construct a closed riser timber staircase given the following.
• Rise of flight – 2.400m• Going of flight – 3.900m• Assume rise of – 170mm
• No. Risers = 2.400 .170 = 14.117 say 14
• Height of Riser= 2.400 14= 171.428say 171
• No. of Goings = 13 (one less)• Length of going
= 3.900 13= 300
• Check for easy going 2R + G = 550 to 700 (2 x 171) + 300 = 642 OK
Revise Definitions
• Handout
• Complete names on handout & review on completion
Types of Stairs
Ref: Carp 18 Textbook – from P6
Straight Open Riser
Dogleg
Quarter Turn
Geometrical circular
Spiral or Helical
Types continued – from P5 - 9
• Review text for type combination
• Brick• Concrete• Steel or Iron• Other types• Timber
BCA
• Your 2011 workbook on stairs (first section)
• Your text and other printed information, makes frequent reference to BCA requirements, review some of these in the handout
Timber Stairs
Ref: Carp 18 textbook – P25 – 29
Open Riser Stair
• From P27• Also your first
practical exercise• Review these few
pages in your textbook
Closed Riser Staircase
• Your 2011 workbook from P 36
• Review Handout, this will be your second practical project
Rise of step
Margin line
Closed Riser Stair Set - out
Wedge Detail & Size
Nosing line
Tread Detail of Housings
Closed Riser Staircase
Template you made in the workshop
Tenon Details
Copy into your handout
Newel set - out
Newel set – out continued, also P23 carp 18
Stair calculations includinglength of string
Example P31 – carp,18
Stair calculations
• Review example of calculations on P31 of your textbook
Complete exercises
Workbook from P 17
“Extra” Calc’s exercise No. 1
• Copy the following and complete
• Calculate the quantity of timber required for the open riser stair with following spec:– Rise of flight 850mm– Going of flight 1.100m– String material 250mm x 38mm sawn H/W– Treads 40mm thick sawn H/W– Width of stair 1.200m– Assume rise 160mm
Answer – note: this symbol √ below means square root
• No. of Risers= .850
.160= 5.312 say 5 risers
• Height of riser= .850 = 170mm
5• No. of Goings = 4• Width of going
= 1.100 4
= 275mm• 2R + G
= (2 x 170) + 275 + 615 OK
• Length of string√ (rise of flight)² + (going of flight + one going of step)²
√ .850² + (1.100 + .275)²√ .850² + 1.375²√ .723 + 1.891√ 2.614= 1.617
• Order 1.8m lengths• String 250 x 38 H/W 1 @ 3.6• Treads 275 x 40 H/W 1 @ 4.8
• You don’t have to show all the working, but for this example it shows you the full answer
Calc’s Exercise No. 2• Copy the following & complete
• Calculate the timber order for a closed riser flight of stairs to suit the following spec:– Rise of flight 2.450m– Going of flight unrestricted try 280mm– Rise of step approximately 160mm– Riser boards 19mm thick maple, 20mm
nosing– Treads 40mm maple– Stringer 350 x 40mm Maple– Width of stairs 2.600m
Answer No. 2• No. of Risers
= 2.450.160
= 15.310 say 15 risers• Height of riser
= 2.450 = 163mm 15
• No. of Goings = 14• Width of going - unrestricted
= 280
= 280mm• 2R + G
= (2 x 163) + 280 = 606 OK
• Length of string√ (rise of flight)² + (going of flight + one going of step)²
√ 2.450² + (3.920 + .280)²√ 2.450² + 4.200²√ 6.003 + 17.640√ 23.643= 4.862
• Order 5.1m lengths• String 350 x 40 Maple 2 @ 5.1• Treads 300 x 40 Maple 7 @ 5.4
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