Decking and damproof course level

[descantrules]

In the projects pages of the site there is a picture of some decking outside a patio window which is clearly above the damp proof course not 150mm below it. So is the quote below relevant, if so is there an answer.

[quote="thedoctor"]Nothing in your garden, including decking, which is up against the house, should be any higher than 150mm BELOW the damp proof course. The damp proof course is there to stop water soaking up the bricks and getting into your house, if you place things against the wall which will allow the rain to splash against the wall above the dpc it can soon soak the wall and lead to damp indoors. [/quote]

I want to lay my decking over a concrete patio so at best can only get level with the damp proof course, could I insert some flashing in the wall 150mm above the decking level to prevent water splashing on the wall?

I intend to lay the joists direct on to the concrete with mortar piles to lift the wood above the surface to allow for drainage, do I need to give additional water treatment to the wood where it contacts the mortar?

Any help would be great as I'm keen to get on with the project.