photo credit: Donna Cazadd via cc
The first step is to decide the contour of the walkway, do you just want a simple straight line or do you desire something that flows better with the surrounding topography? For a straight walkway determine the width and stake the four corners of the walkway and then run a string line between the stakes. For a curving, winding walkway you can use string, garden hoses, or extension cords- whatever is handy- and lay them out in the contour you desire, then use some spray paint to mark this boundary line. Then get out the shovels.
You will need to dig about 2-2 and a 1/2 inches deep, its best to use a flat type shovel and "scrape" the sod (sod is the grass and a thin layer of dirt that is held together like a mat by the root system of the grass), this sod will be used to "touch up" the edges of your walk and any leftover can be used elsewhere. Be sure to keep the sod moist and in a shady area until you need it so the grass doesn't die.
When you have the pathway dug you will then use the flat shovel and a rake to make the surface flat and even, although it has to be flat, it will NOT be level, it needs to shed water. Make one side (the side nearest any structures) a little higher than the other side, about one quarter inch per foot or so of width, it doesn't have to be perfect. For example, a 3 ft. wide walkway should be at least ½ inch, but no more than ¾ inch, higher on the structure side.
Once you have the pathway dug nice and smooth, flat, and slightly curved, it is a good idea to line the pathway with landscaping cloth. This will prevent weeds from growing up between the stones yet still allow water to drain. If you use a solid plastic liner the dug pathway will hold water, this is not desired.
After lining the pathway with the landscaping cloth, put an even layer of sand on the pathway, about ½ inches deep, and then tamp the sand with a wide, flat object. An actual tamper would be best but if you don't have one something can be improvised. The sand allows you to make adjustments to the flagstones so the edges line up better, you do not want any edges protruding up and creating a trip hazard.
After tamping the sand, place the flagstones in the pathway leaving about ½ inch between them, some cutting of the stones will be necessary to achieve a tight fit and sometimes you may need to place small pieces between larger stones to fill gaps. Cutting the stone is done with a chisel and mini-sledge hammer.
Once the flagstones are all in place then you just spread sand over the entire walkway working it into the gaps between the stones, a push broom is handy for this as it will not scratch the stones surface, although a regular broom can be used. DO NOT use a metal rake for this. Finally, gently but thoroughly wet the walkway so that the water helps to settle and compress the sand. You now have a beautiful flagstone walkway.
Recommended Links:
http://en.wikipedia.org/wiki/Flagstone
http://www.vanbeeks.com/product-catalogue/rock-flagstone
http://www.houzz.com/flagstone-patio
