Can't find my survey bars I am trying to determine where my property line is. My neighbour is putting in a concrete pathway down the side of her house, between our two houses. I want to make sure that she stays on her side of the boundary line. A friend o

A couple of things that you may not be ware of. First, survey bars are official survey monuments designed to enable land surveyors to communicate to each other (often over long periods of time) where boundary points are "on the ground". Survey monumentation is how surveyors take what's on paper (the land survey plan) and reflect it on the ground. The survey bars are not intended for the general public to use.

Second, residential properties (at least in Ontario) are only required to have survey bars placed at the front two corners of the property and not the back. Commercial properties always have them at the back as well.

Third, survey bars deteriorate over time. A bar set thirty years ago may have rusted and disintegrated, so sometimes there are not any bars where you'd expect them to be.

Having said all this, you can, in fact, look for your bars to get an idea of where tour property lines intersect the street line. These bars are usually buried so that their tops are a couple on inches below the surface. 

Knowing where the front two bars are does not, however, allow you to gain any sort of certainty as to where the property line runs. Your best bet, in this particular case, is to have a surveyor come and stake out your boundary. This is your only sure-fire way of knowing exactly where the boundary is and whether or not your neighbour is encroaching.