Laying a Stone Patio - Impact on the home foundation?

Question:We recently moved to a new house and we have decided to build a patio may be 15"x15" close to the house foundation. I have decided to do it myself, though I have never done these kind of things before. Pretty much every instruction says to dig the ground to about 10 inches and use pebble stones and sand for foundation before I layer the stones.. My question is if I do this is this going to affect my home foundation if water goes down through the cracks between stones and the edges into this 10 inch layer... I don't want any potential damage for the foundation due to this and having to deal with warranty issues (we have a 10 year foundation warranty)... Is this something that I should worry about? Should I think of building this patio may be a little away from the foundation.

My second question is I have sprinkler heads close to the foundation and if I build a patio, then I have to move these sprinkler heads out. How would I do this?

Please give me details.

Answers:
constructing a stone patio as you suggest should not have any affect on your foundation as long as you don't remove any soil directly beneath the concrete you may want to dig your sub grade at an increasing depth away from the foundation to expedite drainage away from foundation.
as for the sprinkler heads if the piping is pvc just cut them off glue on necessary fittings to affect required direction or depth then extend new piping to new location ok to route piping thru gravel layer.