Raised Deckings - Post Spikes?

[mozza42]

We want some quick 'n' easy decking for the Garden, to go over an almost level grassy area... Was thinking about using posts in the ground to raise the deck where needs be - are post spikes suitable for this application? The ground is not solid since it was landscaped a few Months back, so I gather we're going to have to have some fairly deep (500mm?) foundations...?

Post spikes would definitely be easier than concreting posts in - which I'm not averse to doing, should the concensus be that spikes are bodging it!

Any help much appreciated!