Question
What kind of sand do I use for pavers?  Is cement sand ok?  Also, is cement sand 30 mesh sand?  Someone told me to use the smaller grain sand - 30 mesh?  Thank you

Answer
Hello, Virginia;

揅oncrete Sand? or ASTM C-33, (I won't bore you with sieve/mesh sizes*)is course and will cause 揵ridging?if used to fill joints (more on bridging, below). The Concrete Sand is best for the compacted underneath/base of a paving installation. Another alternative for the compacted base is called 揷rusher fines? but isn抰 available in all areas.
 
揗asonry Sand? or ASTM C-144 is more fine, and the best for top dressing the pavers. The reason for the more coarse bedding sand is that Mason sand allows for a greater percentage of particle fines, which could trap water in the bedding layer;  The bedding layer is intended to help  the movement of water, away and avoid erosion from underneath.  

The more coarse Concrete Sand is not as good at completely fill in the joints, due to the particle sizes, and you'll frequently get a "bridging" effect.  This is where sand gets hung up on the joints a little, on its way to try and fill the joints of the pavers. This larger sand will eventually settle, revealing voids that can cause a loss of vertical interlocking or create aesthetic problems.

True 揗asonry Sand?is still angular and will lock up very well while more easily finding its way into the joint. Just be sure you don't use silica sand or play sand ?it is way too fine.

Finally, Polymeric Sand is an excellent (but slightly more expensive) alternative choice for the top dressing of the joints. There are a number of manufacturers (see www.icpi.org).  

Polymeric sand is usually only sold in bags, and I haven抰 seen it at the large 揜etail?stores like Home Depot / Lowes厃ou can get it a specialty stores that sell pavers (there are three in my area).  It hardens after applying, and gets wet.  It won抰 blow out of the joints, and also keeps ants and stuff out of the patio or walk.

If this paver area is in a high-traffic spot or you plan on sealing the pavers, I抎 spend the extra few dollars and go with polymeric sand.  A better over-all finish.

To recap ?Concrete sand below the paver, and Masonry Sand or Polymeric above; Avoid silica/play sand.  Hope it helped. ~Marc

P.S.
* If you REALLY want mesh sizes for "cement sand" vs. "masonry sand", here is a link:
www.claypaver.com/pdfs/bullets/Tech_Bullet_6.pdf