Download presentation

Presentation is loading. Please wait.

Published byElla Bond Modified about 1 year ago

1
Stairs and Ramps. Design and Calculations Unit Standard Calculation Guide

2
Example 1 A single flight of stairs must have a rise between 165 and 175. The total rise is Calculate a suitable rise and going.

3
1200 To calculate the rise for each step you need to divide the total rise by a number between 164 and 172. We will choose ÷ 168 = 7.142

4
1200 Now divide 1200 by 7. This will give us a rise that will add up to exactly ÷ 7 = ( As the fraction of a millimetre is less than.5 we round down to 171) Now we know that each riser is 171 mm.( 171 X 7 = 1197)

5
Sometimes the tread or going of the stair is restricted. We can design a suitable going in the same way that we designed the rise in the previous example

6
Minimum gap to door 400mm Total rise 2660 Restricted going 3650 A formula to achieve this is No. of steps =(2x total rise+ total going) ÷ 600

7
Total rise 2660 Restricted going 3650 A formula to achieve this is No. of steps =(2x total rise+ total going) ÷ 600 Total rise 2660 Restricted going 3650 No. of steps =(2x total rise( 2660)+ total going)(3650) ÷ 600=14.95 ( try 15) So 2660 ÷ 15= mm (step height).

8
Minimum gap to door 400mm So now we know that we have 15 steps 177mm high

9
– 400 = 3600 Minimum gap to door 400mm The going can now be worked out with the formula going = 600 –( 2x rise) Or 600- (2x177) = 246 Total going = 14 x 246= 3444 Less than 3600 so this will work

10
Note that there are is one more riser than treads.

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google