Treating underside of decking boards

Hi All,

Firstly, thanks to all who contribute on this forum, it really is a great resource.

I am fixing Batu decking boards onto treated pine joists (will be using 10g / 65mm SS Type 17 Decking Screws). As a portion of the deck will be around a swimming pool (hence the SS Screws), I have painted all bearers, posts and joists to help with the extra water that will be "splashed" over the decking. I plan on using decking oil for the Batu, but before I commence laying the decking boards, I was considering treating the bottom of the board. Obviously I only have one go at this, as I have no intention of crawling around under the deck in 6 to 12 months re-painting or oiling the underside of the boards.

Should I simply apply a few coats of decking oil to the underside of the boards before fixing? Any other options ?

FYI - reeded side will be down.

Cheers,

Bushy