Maximum floor joist spans

[tony1851]

round

My bending stress in BS5268 shows 5.3N/mm which factors up to 6.1 with load sharing?

Quite correct and well-spotted!; I mistakenly looked at the C18 column, which gives 5.8, when of course it should have been 5.3 - should have kept that Specsaver's appointment.

Could I ask how you get to 6.1? I always assumed the load-sharing factor was 1.1, which takes it up to 5.83.

There is also the 'depth factor' we can apply which I think is 1.08 for 6"-deep timber, which takes it even higher, to just under 6.3.

 

[Bouy]

round

Quite correct and well-spotted!; I mistakenly looked at the C18 column, which gives 5.8, when of course it should have been 5.3 - should have kept that Specsaver's appointment.

Could I ask how you get to 6.1? I always assumed the load-sharing factor was 1.1, which takes it up to 5.83.

There is also the 'depth factor' we can apply which I think is 1.08 for 6"-deep timber, which takes it even higher, to just under 6.3.

Similar thing Tony except my understanding is that the basic stresses are applicable to a 300 deep beam and there is a K7 factor - (300/h)0.11 - that can be applied for beams 72<h<300 (BS 5268 Cl.2.10.6)

 

[Bouy]

Similar thing Tony except my understanding is that the basic stresses are applicable to a 300 deep beam and there is a K7 factor - (300/h)0.11 - that can be applied for beams 72<h<300 (BS 5268 Cl.2.10.6)

Which gives the same value as you, only difference I have to calculate it (or my spreadsheet does) and you memorise these values, awesome