Notching timbers instead of drilling....

[davesparks]

DAVE, you made a very valid point earlier about electricians using their intelligence. Whichever engineer worked out that it is safer to slot a joist where it an sag rather than where it can be supported, well.......

Yes, have you studied the stress diagrams for beams?
Have you considered what the effect on the strength of the joist will be by thinning it at the point where it is supported?

Have you ever noticed how splits in timber tend to start where someone has cut through the fibres of the grain?

I learned a lot of this stuff from my father who was highly qualified in structural and building work and a very well respected building control officer.

If you look at the actual stress patterns, areas of tension and compression etc in a joist you can remove much of the middle of the joist at 1/3 of the span leaving a relatively small amount of the top and the bottom of the joist with minimal effect on its strength, but a hole drilled through the centre at the end or middle of the span can have a much bigger affect on its strength.

 

[Mike Johnson]

Just think of Castellated beams to get the idea, but note the shear webs near the bearing points.

 

[LastManOnline]

Yes, have you studied the stress diagrams for beams?
Have you considered what the effect on the strength of the joist will be by thinning it at the point where it is supported?

Have you ever noticed how splits in timber tend to start where someone has cut through the fibres of the grain?

I learned a lot of this stuff from my father who was highly qualified in structural and building work and a very well respected building control officer.

If you look at the actual stress patterns, areas of tension and compression etc in a joist you can remove much of the middle of the joist at 1/3 of the span leaving a relatively small amount of the top and the bottom of the joist with minimal effect on its strength, but a hole drilled through the centre at the end or middle of the span can have a much bigger affect on its strength.

That is a persuasive post and one I will not ignore