Basic Bearer & Joists Calculations

1. Basic Bearer & Joists Calculations The following two slides will help you understand the calculation process for Bearer & Joist Calculations First look at the information provided, then simply click your mouse to bring in each point. Created by M. S. Martin October 2007 Revised 2009

2. Allow for bearers to run the long way of the building. Width of Building + 1 Bearer Spacings 5.400+ 11.800 = 3 + 1 = 4 in total Refer to the sketch & keep clicking your mouse to see how this works Your timber order will have to indicate orderable lengths, and bearers must join over a pier, so You Could order for this job in 3.6m lengths, multiples of 1.8m pier spacings. However better practice would be to stagger joints – see picture & click mouse again Final order = 4 @ 5.4m & 4 @ 1.8 100 x 75 HWD Below is a basic single room dwelling as an example for these bearer & joist calculations Spec: 100 x 75 HWD Bearer @ 1.8m centres 100 x 50 HWD Joists @ 0.450 centres Formula: Number of Bearers = Width of Building + 1 Bearer SpacingsClick your mouse to reveal each step in the calculation. 1 2 5.400 3 + 1 7.200 = 4 Bearers

3. Formula: Number of Joists = ( Internal room size + 1 ) + double joists Spacing of Joist Click your mouse to reveal each step in the calculation. • Allow for Joists to run the shortest way of the building • ( internal room size + 1 ) + double joists Spacing of Joist • ( 7.000 + 1 ) + 2 (note we deduct • 0.450 wall frame width) • ( 16 + 1 ) + 2 • = 17 + 2 • = 19 Joists • Refer to the sketch & keep clicking your mouse to see how this works • Below is a basic single room dwelling as an example for these bearer & joist calculations • Spec: • 100 x 75 HWD Bearer @ 1.8m centres • 100 x 50 HWD Joists @ 0.450 centres • 100 x 50 Oregon wall frame +1 = 17 1 3 5 7 9 11 13 15 5.400 Your total timber order will be 19 @ 5.400m 100 x 75 HWD 8 10 2 4 6 14 16 7.200 12 + 2 = 19 Joists