Correct nail size for battens + counterbattens

[S1llyB1lly]

Hello folks!

I need to buy some nails to fix down:

(a) Vertical counterbattens (25mm x 50mm)
(b) Horizontal battens (25mm x 50mm)
(c) Fibre cement tiles (60cm x 30cm)

My thoughts are as follows (please can somebody correct me if I am wrong?)

(a) Vertical counterbattens will be used to pin down breathable membrane. I'm thinking to nail the counterbattens with 40mm long aluminium nails, on the basis that the batten is 25mm thick, so this will allow the nail to sit around 15mm into the rafter for a secure fit.

(b) Horizontal battens - I am a bit confused here. Should the nail go into the vertical counterbattens only (in which case I just need 40mm long aluminium nail) or should the nail go through both batten + counterbatten and into rafter, in which I need 25mm (batten) + 25mm (counterbatten) + 15mm into rafter for good measure, in which case I need 65mm?

(c) I will use 35mm copper nails for the 60cm x 30cm fibre cement slate tiles, accompanied by a 19mm copper rivet.

Thoughts, comments and opinion welcome.

 

[mfarrow]

I would use 50mm galv nails for both battens/counterbattens. Don't buy toolstation, too thick.

 

[mfarrow]

Repeat. Thanks to Apple.

 

[Banksy61]

65x3.35mm galv wires for counter battens and battens and 30x3.0mm copper clouts for the slates

 

[dom_k]

I used 65mm for my counterbatten and then again for battens

 

[S1llyB1lly]

Thanks for the comments folks. I just popped into a branch of a trade DIY chain, and was told that I should use stainless steel screws instead of aluminium nails for battens? Now I'm really confused. I didn't buy anything, came back on here to check what's going on

 

[Banksy61]

You need galvanised wire nails for the battens, not alloy, we use them all the time. Copper clouts for the slates.