So, you may be asking yourself, what makes a paver permeable? Well, it's all about the joints and the base, baby. First of all, the pavers have lugs on all sides that interlock with the lugs of neighboring pavers, creating approximately a 7/8" space inbetween all the pavers. This joint is then filled in with a small gravel, #8 aggregate to be specific. This gravel-filled joint space is part of the reason why water permeates so easily through this surface. The second reason why this system is so permeable is because of the base construction. It is excavated by at least 12". That is what we did. For larger scale projects, a deeper base might be spec'd. Then we covered the bottom of the hole with a geo-textile fabric. This keeps the soil and patio fill from settling and seeping into one another. Next, approximately 7" of 57 stone, a coarse gravel, was added on top of the geo-textile (compacted in a series of level lifts). Then, another layer of geo-textile was added. Then came 2" of the #8's to serve as a setting bed for the pavers. The pavers were set in and their joints filled with the #8's. Finally, the whole patio was compacted with a vibratory plate compactor. Voila! There you have it, a permeable patio.
So, that's the quick and dirty of it all. Techo-Bloc provided us with some nice technical materials that I referenced in writing this little tid-bit. See picture below, from said materials, which gives a nice cross-section of a standard permeable patio. Also, check out the link below for some pictures of the kiosk patio being built.

One more thing...if you would like to check out the materials we used for yourself, you can go by Chandler Concrete of Virginia, Inc., located in Christiansburg. They carry the Techo-Bloc pavers as well as the Grotto Hardscapes weathered parapet blocks used for the wall.
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http://www2.snapfish.com/snapfish/thumbnailshare/AlbumID=2328013020/a=1591487020_1591487020/otsc=SHR/otsi=SALBlink/COBRAND_NAME=snapfish/