Screws for a cedar fence

[jregovic]

I am going to rebuild a fence on my patio. I live in a condo and the posts are steel I-beams, so I am only replacing the beams and the boards.

My plan is to use 16 cedar boards, but I am unsure what kind of screw to use. I have seen options for flat head and trim head and can't really figure out what would be best to use. The boards will run horizontally rather that vertically, and I don't know if this matters.

I am assuming that a #8 2" should work, but I am confused as to the head type.

 

[r896neo]

Not sure what trim head translates too here in the uk but for outdoor timber i always use a secure driving head which is easier to get out in a couple of years if you need to.

Something like a spax torq drive or even a robertson square drive.

http://www.spax.com/uk/technical-terms/spax-t-star-plus