DO I need two under eaves rows with vertical tiling?

[MikeSharp01]

I am moving to put the outer cladding, fibre cement slates, on our build and have been playing with the set out and when looking at it I cannot see a reason for two layers of under eaves slates. The eaves are of course effectively the bottom of the wall in vertical slating. I will be kicking the bottom out with a batten and I can rest the rivet on that and between the single under eaves slates. What am I missing?

[saveasteading]

You should do whatever the manufacturer shows.

However:

The extra tile props up the upper tile in the same way that every other tile is propped by the one below. The line is better to look at, and the slope does not increase into the gutter.

Also extra weight against the  wind at a vulnerable edge.

[Simplysimon]

57 minutes ago, MikeSharp01 said:

What am I missing?

nothing as far as i can see. no need for extra cover as vertical, however, if timber batten then there will be a gap between first row of slates where water will penetrate and possibly sit on top of batten if not bevelled.  how are you fixing as they may rattle?

[Big Jimbo]

Mike, Not saying im right, but in the past on vertical hung slate, i've done a strip of mineral felt behind the bottom row. I figured that protected the bottom batten, and provided me with the kick out to provide a match up with the angle of the overlapped tiles above.

[MikeSharp01]

2 hours ago, saveasteading said:

Also extra weight against the  wind at a vulnerable edge.

its 150mm off the ground at the bottom.

[MikeSharp01]

1 hour ago, Big Jimbo said:

Not saying im right, but in the past on vertical hung slate, I've done a strip of mineral felt behind the bottom row.

Yes I thought that and that would overcome the issue from @saveasteading and save me a bunch of slates. I can also screw the bottom under eaves slates to the battens to prevent rattling.

[saveasteading]

"Eaves" confused me. Have read again and see you mean " like the eaves" . So do your way.