Use shorter nails for the first natural slate eave course?

[epsilonGreedy]

I have a 1kg bag of 30mm long copper clout nails for my new roofing project. Given 25mm thick roofing battens and 5mm thick slates and the fact at the point of fixing the new slate is resting on its downhill buddy slates in the course below then a 30mm long fixing nail will stop within the batten wood and so no risk of the nail puncturing the underlay membrane.

 

However an eave course slate rests directly on the first roofing batten. In this case there is a risk of fixing nails punching through into the membrane.

 

In view of this concern should I fix the eave course slates with shorter clout nails, say 25mm long?

[joe90]

Sounds positively pragmatic (that’s a yes) ?

[David H]

hmm I might have to test on a broken slate and some spare batten. My tiles are 5.5mm thick apparently :) and was hoping they would be ok, as you don't hammer them too tight but will do a quick test. I am using slate hooks for the main courses, it's just the eave course that's nailed. Literally only just ordered the 30mm copper nails then saw your post :)

I am using slate hooks as the pitch is 20 degrees and I read that it's better to use hooks at a low pitch but I have also seen some web sites that contradict that advice, so who knows!

[epsilonGreedy]

14 minutes ago, David H said:

hmm I might have to test on a broken slate and some spare batten. My tiles are 5.5mm thick apparently and was hoping they would be ok, as you don't hammer them too tight but will do a quick test. I am using slate hooks for the main courses, it's just the eave course that's nailed. Literally only just ordered the 30mm copper nails then saw your post 

 

 

My eave course slates are the thicker ones out of my grading process. Even so I have realized that the nail holes have a counter sunk profile which means the nail heads sits within the tile thickness. With my roof the eave course batten pinches down on the plastic eave support tray which is a couple of mm thick but I would still like avoid any chance of a nail poking through.

 

I wonder of a sharp pair of pliers could snip 3mm off a copper nail?

[Roys]

8 minutes ago, epsilonGreedy said:

 

 

I wonder of a sharp pair of pliers could snip 3mm off a copper nail?

Easily, no problem at all, put nail as close to the hinge part of the pliers as possible.