I just had a conversation last week about this subject with a wood scientist from a lumber wholesaler/mill.

There is more to be concerned with than that it not touch the ground. They recommend that it be at least 18" above the ground with free ventilation through. Here in this part of Maine, we try to do that anyway because of carpenter ants. Other parts of the country experience termites and other vermin.

You might seal the top and then have moisture trapped underneath so the mold and rot attack the wood from that direction. Ants and bettles might burrow through and drag bacteria with them. so provide ventialtion and seal the wood on al four sides first before application.

There are a lot of kinds of pine. Overall, it is not one of the first choices for decks because it is not that strong and it rots easily. Cedar, redwood, and fir are better North American wood choices. Ipe`, pau Lope', and canberra are tropical hardwood exotics that make good choices. You should probably also consider the manmade deck materials like Trex and Correctdek

Excellence is its own reward!

There were two reasons for the desire for the pine. One I love the grain. Second is the price. When I am looking at installing roughly 5,000 sq ft of decking cost becomes a factor.

Rongee

Pine must be cheaper there than it is here, and after walking on it for a year and then seeing it start to rot. the grain won't make too much difference in what you are looking at.

Excellence is its own reward!