Is there any problem with decking up to a house wall. i.e. if I lay
decking on top of an existing patio, the level of the decking will
only be 1 brick below the damp proof course of the house, possibly
less, instead of the 2 bricks that it is presently between the patio
and the damp proof.

Obviously with decking, water will run through the boards and so will
not build up, but should I be worried about rain splash back causing
damp?

What is the usual procedure with this type of work, I dont really want
to rip up all the patio to dig it down deeper before laying the
decking if can help it.

Thanks

Tom