Urban Poison Ivy

I mentioned in my last post ("the humidity cometh") that the poison ivy out here grows to epic proportions.  Little did I know at the time, that it also thrives in urban settings.  No sooner had I finished that post, than I was standing at my kitchen window, staring at a plant that looked suspiciously like poison ivy in my back patio.  Now, something you should know about my back patio is that it is made entirely of pavers.  There is no lawn, there is no garden, there are no flower beds, it is comprised solely of gray paving stone.  Of course there are weeds, but I'm plucking them out like a teenager pops their pimples: aggressively and knowing the darned things are just gonna sprout back up.  Anyway, between my patio "wall" and my neighbor's yard (which is elevated above mine, so they have a wall too) is a gap.  Occupying this gap is an assortment of weeds, included in this assortment, much to my chagrin, is poison ivy.  How in the h-e-double hockey stick did it get there? And how is it thriving?  My weed "garden" offers very little shade and in fact the poison ivy is located such that it gets direct sunlight all afternoon.  Those not versed in poison ivy lore may be saying "so?".  Poison ivy is a plant that thrives in shaded, cool, damp locations.  It has innocuous looking, bright green, leaf-shaped leaves (think of a leaf that a 4-year-old would draw).  They are broad with smooth edges, some larger ones have scalloping along the edge, and a mild sheen on the top surface (though most things around here have a mild sheen, thanks to the humidity).  The hallmark of poison ivy, and what tipped me off in this case, is that the leaves grow in clusters of 3 on a single stalk.  We have poison ivy in Colorado, it is most commonly seen growing on the shaded slopes of  mountains.  There it grows as a ground covering, which has always made me wonder why it's called poison IVY.  Well, now I know.  The plant in my back patio did not originate from the soil between the walls, it's a tendril that has creeped its way down the wall from under a bush my neighbor's yard.  Which simultaneously solves the mystery of why this piece of poison ivy is in a sunny-ish location instead of the favored shaded, damp, cool location: the majority of the plant is in the latter-mentioned locale.  Which brings me to the next problem of, how am I going to get rid of it?  I can't very well just rip it out (I don't want to test the waters of that itchy, red, rash) and Round-Up isn't going to target the root very well.  As my sister said when the diagnosis of 'poison ivy' was confirmed, "have fun with that. :-)"