As you can see from the following graphic these require nailing in to the e dge of a board (for which galvanised nails are provided) and then butting u p and under the previously affixed board, the latter requiring its free edg e skew-nailing into position:
I can't help but feel that using screws instead of nails might be worthwhil e for the skew-nailing to at least give me the option of being able to pull the boards up at a later date. Why I'd want to do this I don't know, but i f one thing's for certain a reason would present itself if I was to irrever sibly fasten the boards down!
So, I'm wondering if anyone can make a recommendation as to what screw size /type to use? I am mindful of the outdoor aspect, wanting to minimise split ting (the boards are 33mm thick by the way), ease of installation (pilot ho le required?), not wanting the head to be (too) proud and visible through t he 3mm gap etc.
The range on offer at the likes of Screwfix is bewildering to be honest and whilst I've been using their Goldscrews for years for indoor projects I'm wondering if there's something more suitable for this particular job.