Qitzur Shulchan Arukh – 183:7
Even doing something in his own domain something which causes damages to his neighbor is prohibited. He should not place in his courtyard, adjacent to his friend’s wall, anything which has [and gives off] heat, or gives off gases, or would [otherwise] damage the wall, such as manure and the like, unless if he keeps it a distance of 3 tefachim [roughly 9″; enough to keep the heat or fumes from damaging the wall]. Similarly, he has to keep distant so as not to spill water adjacent to his friend’s wall. Therefore, a gutter which drains [water] from the roof, he must distant it[s outlet] 3 tefachim from his friends wall. All the more so not to spill a chamberpot of urine adjacent to his friend’s wall. To urinate adjacent to his friend’s wall, if it is a wall of stone of of wood without tarring [or plaster], it is enough to keep a distance of 1 tefach [3″ or so]. If it is of stone fitted into stone, he doesn’t have to keep any distance, and can even urinate against the wall. If it is a brick wall, or of tarred [or plastered] wood, he has to keep a distance of 3 tefachim. See more in the next siman [184, which deals with physical damages; ie injury].