Weeding between pavers is a chore that no one relishes, but there are ways to hinder weeds from growing. While the method does eventually allow weeds to come through, as with commercial weed barriers, it slows weed growth considerably, especially during the first couple of years. A second method completely blocks weeds and is easier, but you may have to replace the barrier every few years -- or pull the weeds.
Dig an 8-inch trench the length and width of the area you are going to pave. Layer the 2-inch gravel on the bottom of the trench about 4 inches deep. Shovel an inch of sand over the top of the gravel. Spray the sand down so that it packs itself into the gravel.
Add 1 inch of sand over the gravel and sand layer. Wet the sand down again, taking care to not wash the sand away. Layer the 1-inch gravel in a 2-inch layer over the previous layers. Spread sand on top of the gravel. Spray the sand to encourage it to pack itself between the gravel.
Add an inch of sand, then wet the sand again to encourage it to pack itself into the gravel. Rake the sand evenly. Add enough sand to make the layers even with the top of the trench. Wet the sand and rake it even.
Fit the pavers into your design on top of the sand. Stamp the pavers down as you install them. If the pavers are not level, adjust the sand under that paver to make it level.
Dig the sod out of the area in which you wish to install pavers.
Spray the area with weed killer. Cover the area with the plastic sheeting.
Install the pavers.
If you use the plastic barrier method, the plastic eventually cracks after a couple of years and allows weeds to grow between the pavers. Keep some weed killer on hand or pull the weeds once they start growing through. The thicker the plastic you use, the longer it stays intact and blocks weeds.
If you use the plastic barrier method, it is harder to make the pavers even. If you are building a patio or walkway, use the first method, as that also provides stability for the pavers, not to mention the ease of levelling them as you install them.